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Whitaker-Fornek JR, Nelson JK, Pilarski JQ. Chloride Modulates Central pH Sensitivity and Plasticity of Brainstem Breathing-Related Biorhythms in Zebra Finch Embryos. Dev Psychobiol 2024; 66:e22518. [PMID: 38924086 PMCID: PMC11210689 DOI: 10.1002/dev.22518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 05/26/2024] [Accepted: 05/28/2024] [Indexed: 06/28/2024]
Abstract
All terrestrial vertebrate life must transition from aquatic gas exchange in the embryonic environment to aerial or pulmonary respiration at birth. In addition to being able to breathe air, neonates must possess functional sensory feedback systems for maintaining acid-base balance. Respiratory neurons in the brainstem act as pH sensors that can adjust breathing to regulate systemic pH. The central pH sensitivity of breathing-related motor output develops over the embryonic period in the zebra finch (Taeniopygia guttata). Due to the key role of chloride ions in electrochemical stability and developmental plasticity, we tested chloride's role in the development of central pH sensitivity. We blocked gamma-aminobutyric acid-A receptors and cation-chloride cotransport that subtly modulated the low-pH effects on early breathing biorhythms. Further, chloride-free artificial cerebrospinal fluid altered the pattern and timing of breathing biorhythms and blocked the stimulating effect of acidosis in E12-14 brainstems. Early and middle stage embryos exhibited rebound plasticity in brainstem motor outputs during low-pH treatment, which was eliminated by chloride-free solution. Results show that chloride modulates low-pH sensitivity and rebound plasticity in the zebra finch embryonic brainstem, but work is needed to determine the cellular and circuit mechanisms that control functional chloride balance during acid-base disturbances.
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Affiliation(s)
| | - Jennie K. Nelson
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho
| | - Jason Q. Pilarski
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho
- Department of Dental Sciences, Idaho State University, Pocatello, Idaho
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2
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Bhader M, Al-Hindi M, Ghaddaf A, Alamoudi A, Abualola A, Kalantan R, AlKhulifi N, Halawani I, Al-Qurashi M. Noninvasive Neurally Adjusted Ventilation versus Nasal Continuous or Intermittent Positive Airway Pressure for Preterm Infants: A Systematic Review and Meta-Analysis. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1935. [PMID: 38136137 PMCID: PMC10741611 DOI: 10.3390/children10121935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/08/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023]
Abstract
The noninvasive neurally adjusted ventilatory assist (NIV-NAVA) is a newly developed noninvasive ventilation technique with promising clinical and ventilatory outcomes for preterm infants. This systematic review and meta-analysis aimed to investigate whether NIV-NAVA has better clinical and ventilatory outcomes than nasal continuous airway pressure (NCPAP) or noninvasive positive pressure ventilation (NIPP) on premature infants. MEDLINE, Embase, and CENTRAL were searched, and randomized controlled trials (RCTs) that compared NIV-NAVA with NCPAP or NIPP for preterm infants (gestational age: <37 weeks) were included. We evaluated the following outcomes in the neonatal intensive care unit: the desaturation rate, failure of noninvasive modality requiring intubation when received as the primary mode or the need for re-intubation after extubation from mechanical ventilation in the secondary mode (weaning), length of stay, and fraction of inspired oxygen. The mean difference and risk ratio were used to represent continuous and dichotomous outcomes, respectively. We included nine RCTs involving 339 preterm infants overall. NIV-NAVA showed similar clinical and ventilatory outcomes to NCPAP or NIPP, except for the maximum diaphragmatic electrical activity. The rate of failure of the noninvasive modality was not statistically different between NIV-NAVA and NCPAP. The pooled estimates for the maximum electrical activity were significantly reduced in NIV-NAVA compared with those in NIPP. The findings suggest that NIV-NAVA may be as safe and effective as NCPAP and NIPP for preterm neonates, particularly those who may not tolerate these alternative noninvasive methods. However, further trials are recommended for greater evidence.
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Affiliation(s)
- Mohammed Bhader
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia; (M.A.-H.); (A.G.); (A.A.); (R.K.); (N.A.); (M.A.-Q.)
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
| | - Mohammed Al-Hindi
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia; (M.A.-H.); (A.G.); (A.A.); (R.K.); (N.A.); (M.A.-Q.)
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
- Department of Pediatrics, King Abdulaziz Medical City, Jeddah 22384, Saudi Arabia
| | - Abdullah Ghaddaf
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia; (M.A.-H.); (A.G.); (A.A.); (R.K.); (N.A.); (M.A.-Q.)
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
| | - Anas Alamoudi
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia; (M.A.-H.); (A.G.); (A.A.); (R.K.); (N.A.); (M.A.-Q.)
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
| | - Amal Abualola
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia; (M.A.-H.); (A.G.); (A.A.); (R.K.); (N.A.); (M.A.-Q.)
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
| | - Renad Kalantan
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia; (M.A.-H.); (A.G.); (A.A.); (R.K.); (N.A.); (M.A.-Q.)
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
| | - Norah AlKhulifi
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia; (M.A.-H.); (A.G.); (A.A.); (R.K.); (N.A.); (M.A.-Q.)
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
| | - Ibrahim Halawani
- College of Medicine, King Abdulaziz University, Jeddah 22252, Saudi Arabia;
| | - Mansour Al-Qurashi
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia; (M.A.-H.); (A.G.); (A.A.); (R.K.); (N.A.); (M.A.-Q.)
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
- Department of Pediatrics, King Abdulaziz Medical City, Jeddah 22384, Saudi Arabia
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Tamir-Hostovsky L, Ivanovska J, Parajón E, Patel R, Wang H, Biouss G, Ivanovski N, Belik J, Pierro A, Montandon G, Gauda EB. Maturational effect of leptin on CO 2 chemosensitivity in newborn rats. Pediatr Res 2023; 94:971-978. [PMID: 37185965 DOI: 10.1038/s41390-023-02604-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 03/28/2023] [Accepted: 04/01/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND Leptin augments central CO2 chemosensitivity and stabilizes breathing in adults. Premature infants have unstable breathing and low leptin levels. Leptin receptors are on CO2 sensitive neurons in the Nucleus Tractus Solitarius (NTS) and locus coeruleus (LC). We hypothesized that exogenous leptin improves hypercapnic respiratory response in newborn rats by improving central CO2 chemosensitivity. METHODS In rats at postnatal day (p)4 and p21, hyperoxic and hypercapnic ventilatory responses, and pSTAT and SOCS3 protein expression in the hypothalamus, NTS and LC were measured before and after treatment with exogenous leptin (6 µg/g). RESULTS Exogenous leptin increased the hypercapnic response in p21 but not in p4 rats (P ≤ 0.001). At p4, leptin increased pSTAT expression only in the LC, and SOCS3 expression in the NTS and LC; while at p21 pSTAT and SOCS3 levels were higher in the hypothalamus, NTS, and LC (P ≤ 0.05). CONCLUSIONS We describe the developmental profile of the effect of exogenous leptin on CO2 chemosensitivity. Exogenous leptin does not augment central CO2 sensitivity during the first week of life in newborn rats. The translational implication of these findings is that low plasma leptin levels in premature infants may not be contributing to respiratory instability. IMPACT Exogenous leptin does not augment CO2 sensitivity during the first week of life in newborn rats, similar to the developmental period when feeding behavior is resistant to leptin. Exogenous leptin increases CO2 chemosensitivity in newborn rats after the 3rd week of life and upregulates the expression of pSTAT and SOC3 in the hypothalamus, NTS and LC. Low plasma leptin levels in premature infants are unlikely contributors to respiratory instability via decreased CO2 sensitivity in premature infants. Thus, it is highly unlikely that exogenous leptin would alter this response.
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Affiliation(s)
- Liran Tamir-Hostovsky
- Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Julijana Ivanovska
- Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Translational Program, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Eleana Parajón
- Cellular and Molecular Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Rachana Patel
- Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Huanhuan Wang
- Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - George Biouss
- Division of General and Thoracic Surgery, Developmental and Stem Cell Biology Program, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Nikola Ivanovski
- Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Translational Program, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Jaques Belik
- Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Translational Program, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Agostino Pierro
- Division of General and Thoracic Surgery, Developmental and Stem Cell Biology Program, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Gaspard Montandon
- Keenan Research Centre for Biomedical Sciences, St. Michael's Hospital, Unity Health Toronto, University of Toronto, Toronto, ON, Canada
| | - Estelle B Gauda
- Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Translational Program, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
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4
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Gangaram-Panday NH, van Essen T, van Weteringen W, Dremmen MHG, Goos TG, de Jonge RCJ, Reiss IKM. Transcutaneous carbon dioxide monitoring during therapeutic hypothermia for neonatal encephalopathy. Pediatr Res 2022; 92:1724-1730. [PMID: 35352004 DOI: 10.1038/s41390-022-02035-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 03/07/2022] [Accepted: 03/11/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND In neonates with post-asphyxial neonatal encephalopathy, further neuronal damage is prevented with therapeutic hypothermia (TH). In addition, fluctuations in carbon dioxide levels have been associated with poor neurodevelopmental outcome, demanding close monitoring. This study investigated the accuracy and clinical value of transcutaneous carbon dioxide (tcPCO2) monitoring during TH. METHODS In this retrospective cohort study in neonates, agreement between arterial carbon dioxide (PaCO2) values and tcPCO2 measurements during TH was determined. TcPCO2 levels during the first 24 h of hypothermia were tested for an association with ischemic brain injury on magnetic resonance imaging (MRI). RESULTS Thirty-four neonates were included. Agreement (bias (95% limits of agreement)) between tcPCO2 and PaCO2 levels was 3.9 (-12.4-20.2) mm Hg. No relation was found between the body temperature and tcPCO2 levels. TcPCO2 levels differed significantly between patients with considerable and minimal damage on MRI; after 6 h (P = 0.02) and 9 h (P = 0.04). CONCLUSIONS Although tcPCO2 provided a limited estimation of PaCO2, it can be used for trend monitoring during TH. TcPCO2 levels after birth could provide an early indicator of ischemic brain injury. This relation should be investigated in large prospective studies, in which adjustments for confounders can be made. IMPACT Transcutaneous carbon dioxide measurements during therapeutic hypothermia in neonates show limited accuracy similar to measurements reported in normothermic neonates and can be used for trend monitoring. Low transcutaneous carbon dioxide levels during the first 24 h were associated with considerable ischemic brain injury on MRI. The value of transcutaneous carbon dioxide measurements during the first 24 h as an indicator of considerable ischemic brain injury on MRI should be investigated in future studies, adjusting for confounders. Transcutaneous oxygen measurements during therapeutic hypothermia showed an inaccuracy that could not be related to a low body temperature.
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Affiliation(s)
- Norani H Gangaram-Panday
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands.
| | - Tanja van Essen
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Willem van Weteringen
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Pediatric Surgery, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marjolein H G Dremmen
- Department of Radiology and Nuclear Medicine, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Tom G Goos
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Biomechanical Engineering, Faculty of Mechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Rogier C J de Jonge
- Pediatric Intensive Care Unit, Departments of Pediatrics and Pediatric Surgery, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Irwin K M Reiss
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
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5
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Barrington KJ. The most immature infants: Is evidence-based practice possible? Semin Perinatol 2022; 46:151543. [PMID: 34895928 DOI: 10.1016/j.semperi.2021.151543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION At extremely low gestational ages, preterm infants are markedly physiologically immature, thus their responses to common clinical interventions may differ from more mature preterm babies. This study was performed to describe the evidence base which is available to make care decisions for such infants. METHODS A literature search of recent large neonatal randomized controlled trials (RCTs) was performed to determine the representation of infants <25 weeks of gestation, and whether it is clear if the overall results applied to the most immature infants. RESULTS Among 30 multi-centre RCTs in neonatology from the last 5 years, many excluded the most immature infants, and those that included them rarely presented the impacts of the intervention on the most at-risk group. Over 25,000 infants of under 32 weeks gestational age (GA) were included in these trials. Eight trials presented results of the primary outcome for infants of <26 weeks GA (n = 2,152) and a further four trials for infants <25 weeks, n = 711. CONCLUSION The evidence base for treatment decisions for the highest risk infants in the NICU is severely limited. RCTs in extremely preterm infants should not exclude the highest risk group, and lower limits of gestational age (or body weight) should be avoided, any infant receiving intensive care should be eligible regardless of how immature. The results among the most immature infants should be presented separately, or be easily available, in order to build a database of effective treatments among infants of 22,23, and 24 weeks GA.
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6
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Abstract
Brain PCO2 is sensed primarily via changes in [H+]. Small pH changes are detected in the medulla oblongata and trigger breathing adjustments that help maintain arterial PCO2 constant. Larger perturbations of brain CO2/H+, possibly also sensed elsewhere in the CNS, elicit arousal, dyspnea, and stress, and cause additional breathing modifications. The retrotrapezoid nucleus (RTN), a rostral medullary cluster of glutamatergic neurons identified by coexpression of Phoxb and Nmb transcripts, is the lynchpin of the central respiratory chemoreflex. RTN regulates breathing frequency, inspiratory amplitude, and active expiration. It is exquisitely responsive to acidosis in vivo and maintains breathing autorhythmicity during quiet waking, slow-wave sleep, and anesthesia. The RTN response to [H+] is partly an intrinsic neuronal property mediated by proton sensors TASK-2 and GPR4 and partly a paracrine effect mediated by astrocytes and the vasculature. The RTN also receives myriad excitatory or inhibitory synaptic inputs including from [H+]-responsive neurons (e.g., serotonergic). RTN is silenced by moderate hypoxia. RTN inactivity (periodic or sustained) contributes to periodic breathing and, likely, to central sleep apnea. RTN development relies on transcription factors Egr2, Phox2b, Lbx1, and Atoh1. PHOX2B mutations cause congenital central hypoventilation syndrome; they impair RTN development and consequently the central respiratory chemoreflex.
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Affiliation(s)
- Patrice G Guyenet
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States.
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States
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7
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Saini JK, Janes TA, MacLean JE, Pagliardini S. Expiratory activity during sleep in children. J Sleep Res 2021; 31:e13539. [PMID: 34921704 DOI: 10.1111/jsr.13539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 11/29/2022]
Abstract
Sleep irregularities and respiratory events (apnea, O2 desaturation or a combination thereof) are often present in the infant population. While inspiration is the main active process in the act of breathing, expiration is generally thought to occur passively. Although commonly considered as quiet during sleep, expiratory abdominal muscles have been proposed to be recruited to promote ventilation, facilitate gas exchange, and reduce the work of breathing during conditions of increased respiratory drive, exercise, or airway obstruction. In this study, we investigated the occurrence of expiratory abdominal muscle activity in polysomnographic studies of subjects (aged 0-2 years) suspected of sleep disordered breathing. Our results indicate that abdominal muscle activation occurs during sleep, most frequently during non-rapid eye movement and rapid-eye movement states compared to slow-wave sleep. Furthermore, abdominal muscle activity was present during regular breathing or associated with respiratory events (apneas or O2 desaturation). In the latter case, abdominal muscle recruitment more frequently followed the onset of respiratory events and terminated with recovery from blood O2 desaturation events. We conclude that expiratory abdominal muscle activity contributes to the pattern of respiratory muscle recruitment during sleep in infants and given its temporal relationship with respiratory events, we propose that its recruitment could facilitate proper ventilation by counteracting airway resistance and O2 desaturation in infancy across different stages of sleep.
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Affiliation(s)
- Jasmeen K Saini
- Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada
| | - Tara A Janes
- Women and Children's Health Research Institute, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada.,Department of Pediatrics, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada
| | - Joanna E MacLean
- Women and Children's Health Research Institute, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada.,Department of Pediatrics, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada.,Stollery Children's Hospital, Edmonton, Alberta, Canada
| | - Silvia Pagliardini
- Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada.,Department of Physiology, Faculty of Medicine and Dentistry University of Alberta, Edmonton, Alberta, Canada
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8
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Nagraj VP, Lake DE, Kuhn L, Moorman JR, Fairchild KD. Central Apnea of Prematurity: Does Sex Matter? Am J Perinatol 2021; 38:1428-1434. [PMID: 32578186 DOI: 10.1055/s-0040-1713405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVE Apnea is common among infants in the neonatal intensive care unit (NICU). Our group previously developed an automated algorithm to quantitate central apneas with associated bradycardia and desaturation (ABDs). Sex differences in lung disease are well described in preterm infants, but the influence of sex on apnea has not been established. STUDY DESIGN This study includes infants < 34 weeks' gestation admitted to the University of Virginia NICU from 2009 to 2014 with at least 1 day of bedside monitor data available when not on mechanical ventilation. Waveform and vital sign data were analyzed using a validated algorithm to detect ABD events of low variance in chest impedance signal lasting at least 10 seconds with associated drop in heart rate to < 100 beats/minute and drop in oxygen saturation to < 80%. Male and female infants were compared for prevalence of at least one ABD event during the NICU stay, treatment with caffeine, occurrence of ABDs at each week of postmenstrual age, and number of events per day. RESULTS Of 926 infants studied (median gestational age 30 weeks, 53% male), median days of data analyzed were 19 and 22 for males and females, respectively. There was no sex difference in prevalence of at least one ABD event during the NICU stay (males 62%, females 64%, p = 0.47) or in the percentage of infants treated with caffeine (males 64%, females 67%, p = 0.40). Cumulative prevalence of ABDs from postmenstrual ages 24 to 36 weeks was comparable between sexes. Males had 18% more ABDs per day of data, but this difference was not statistically significant (p = 0.16). CONCLUSION In this large cohort of infants < 34 weeks' gestation, we did not detect a sex difference in prevalence of central ABD events. There was a nonsignificant trend toward a greater number of ABDs per day in male infants. KEY POINTS · Central apnea is pervasive among preterm infants in the NICU, but potential disparities between males and females have not been thoroughly studied.. · Identification of risk factors for central apnea can lead to improved treatment protocols.. · The rate and prevalence of central apnea events accompanied by bradycardia and desaturation does not significantly differ between male and female preterm infants..
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Affiliation(s)
| | - Douglas E Lake
- Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Louise Kuhn
- Gertrude H. Sergievsky Center, Vagelos College of Physicians and Surgeons, and Department of Epidemiology, Mailman School of Public Health, Columbia University Irving Medical Center, New York, New York
| | - J Randall Moorman
- Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Karen D Fairchild
- Department of Pediatrics, University of Virginia, Charlottesville, Virginia
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9
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Williamson M, Poorun R, Hartley C. Apnoea of Prematurity and Neurodevelopmental Outcomes: Current Understanding and Future Prospects for Research. Front Pediatr 2021; 9:755677. [PMID: 34760852 PMCID: PMC8573333 DOI: 10.3389/fped.2021.755677] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/27/2021] [Indexed: 11/13/2022] Open
Abstract
Infants who are born prematurely are at significant risk of apnoea. In addition to the short-term consequences such as hypoxia, apnoea of prematurity has been associated with long-term morbidity, including poor neurodevelopmental outcomes. Clinical trials have illustrated the importance of methylxanthine drugs, in particular caffeine, in reducing the risk of long term adverse neurodevelopmental outcomes. However, the extent to which apnoea is causative of this secondary neurodevelopmental delay or is just associated in a background of other sequelae of prematurity remains unclear. In this review, we first discuss the pathophysiology of apnoea of prematurity, previous studies investigating the relationship between apnoea and neurodevelopmental delay, and treatment of apnoea with caffeine therapy. We propose a need for better methods of measuring apnoea, along with improved understanding of the neonatal brain's response to consequent hypoxia. Only then can we start to disentangle the effects of apnoea on neurodevelopment in preterm infants. Moreover, by better identifying those infants who are at risk of apnoea, and neurodevelopmental delay, we can work toward a risk stratification system for these infants that is clinically actionable, for example, with doses of caffeine tailored to the individual. Optimising treatment of apnoea for individual infants will improve neonatal care and long-term outcomes for this population.
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Affiliation(s)
- Max Williamson
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Ravi Poorun
- Department of Paediatrics, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom
| | - Caroline Hartley
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
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10
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Harper RM, Kesavan K. Neuromodulatory Support for Breathing and Cardiovascular Action During Development. Front Pediatr 2021; 9:753215. [PMID: 34660498 PMCID: PMC8514987 DOI: 10.3389/fped.2021.753215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 09/03/2021] [Indexed: 01/14/2023] Open
Abstract
Neonatal survival requires precise control of breathing and cardiovascular action, with fatal consequences or severe injury without support. Prematurity presents multiple opportunities to disrupt cardiorespiratory regulation, leading to expressions of apnea of prematurity, periodic breathing, and inappropriate cardiovascular responses to apnea. Failed breathing control can result from altered breathing drives, typically arising from untimely development of sensory or motor coordination processes. Some drives, such as temperature, are a special concern in neonates with low body mass, enhancing susceptibility to rapid body cooling. Chemical drives, such as pH or CO2 or O2, may be inadequately developed; in some conditions, such as congenital central hypoventilation syndrome (CCHS), breathing responses to CO2 or low O2 may be reduced or absent, and coupling of cardiovascular responses to breathing changes are abolished. Sleep states exert profound influences on both chemical and temperature drives, with rapid eye movement (REM) sleep potentially modifying descending temperature influences, and state transitions significantly altering respiratory responses to chemical stimuli. In addition, neonates spend the majority of time in REM sleep, a state which induces a generalized inhibition of skeletal muscle activity that abolishes muscle tone to upper airway and thoracic wall muscles, enhancing the likelihood for obstructive sleep apnea. Although disrupted regulatory drives can often be replaced by positive (or negative) pressure ventilation, such as continuous positive airway pressure or enhanced by manipulating neurotransmitter action via caffeine, those approaches may exert negative consequences in the long term; the lungs of neonates, especially premature infants, are fragile, and easily injured by positive pressure. The consequences of caffeine use, acting directly on neural receptors, although seemingly innocuous in the near-term, may have long-term concerns and disrupts the integrity of sleep. The developmental breathing field needs improved means to support ventilation when one or more drives to respiration fail, and when the cardiovascular system, depending heavily on interactions with breathing, is compromised. Neuromodulatory procedures which manipulate the vestibular system to stabilize breathing or use tactile or proprioceptive stimuli to activate long-established reflexive mechanisms coupling limb movement with respiratory efforts can provide support for central and obstructive apnea, as well as for periodic breathing and cardiovascular action, particularly during sleep.
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Affiliation(s)
- Ronald M. Harper
- Department of Neurobiology and the Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Kalpashri Kesavan
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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11
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Duenas-Meza E, Escamilla-Gil MI, Bazurto-Zapata MA, Caparo E, Suarez Cuartas M, Rincón Martínez L, Pernett Buenaver L, Rojas Ortega A, Torres J, Restrepo-Gualteros S, Parra Buitrago A, Gonzalez-Garcia M. Intermittent Hypoxia and Respiratory Patterns During Sleep of Preterm Infants Aged 3 to 18 Months Residing at High Altitudes. Sleep 2021; 45:6354695. [PMID: 34409457 DOI: 10.1093/sleep/zsab208] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 06/05/2021] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVES the aim of this study was to determine the impact of apneas on oxygen saturation and the presence of intermittent hypoxia, during sleep of preterm infants (PTIs) born at high altitudes and compare with full-term infants (FTIs) at the same altitude. METHODS PTIs and FTIs from 3 to 18 months were included. They were divided into three age groups: 3-4 months (Group 1); 6-7 months (Group 2) and 10-18 months (Group 3). Polysomnography parameters and oxygenation indices were evaluated. Intermittent hypoxia was defined as brief, repetitive cycles of decreased oxygen saturation. Kruskal-Wallis test for multiple comparisons, t-test or Mann-Whitney U test were used. RESULTS 127 PTI and 175 FTI were included. Total apnea-hypopnea index (AHI) was higher in PTI that FTI in all age groups (Group 1: 33.5/h vs. 12.8/h, p=0.042; Group 2: 27.0/h vs. 7.4/h, p<0.001 and Group 3: 11.6/h vs. 3.1/h, p<0.001). In Group 3, central-AHI (8.0/h vs. 2.3/h, p<0.001) and obstructive-AHI (1.8/h vs. 0.6/h, p<0.008) were higher in PTI than FTI. T90 (7.0% vs. 0.5, p<0.001), oxygen desaturation index (39.8/h vs. 11.3, p<0.001) were higher in PTI than FTI, nadir SpO2 (70.0% vs. 80.0, p<0.001) was lower in PTI . CONCLUSION At high altitude, compared to FTI, PTI have a higher rate of respiratory events, greater desaturation and a delayed resolution of these conditions, suggesting the persistence of intermittent hypoxia during the first 18 months of life. This indicates the need for follow-up of these infants for timely diagnosis and treatment of respiratory disturbances during sleep.
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Affiliation(s)
- Elida Duenas-Meza
- Fundación Neumológica Colombiana.,Universidad de La Sabana.,Fundación Cardioinfantil-Instituto de Cardiología
| | | | | | | | - Miguel Suarez Cuartas
- Fundación Neumológica Colombiana.,Universidad de La Sabana.,Fundación Cardioinfantil-Instituto de Cardiología
| | | | - Lisbeth Pernett Buenaver
- Fundación Neumológica Colombiana.,Universidad de La Sabana.,Fundación Cardioinfantil-Instituto de Cardiología
| | | | | | | | - Andrea Parra Buitrago
- Fundación Neumológica Colombiana.,Universidad de La Sabana.,Fundación Cardioinfantil-Instituto de Cardiología
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12
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Wang X, Guan R, Zhao X, Chen J, Zhu D, Shen L, Song N. TASK1 and TASK3 in orexin neuron of lateral hypothalamus contribute to respiratory chemoreflex by projecting to nucleus tractus solitarius. FASEB J 2021; 35:e21532. [PMID: 33817828 DOI: 10.1096/fj.202002189r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/19/2021] [Accepted: 03/01/2021] [Indexed: 11/11/2022]
Abstract
TWIK-related acid-sensitive potassium channels (TASKs)-like current was recorded in orexin neurons in the lateral hypothalamus (LH), which are essential in respiratory chemoreflex. However, the specific mechanism responsible for the pH-sensitivity remains elusive. Thus, we hypothesized that TASKs contribute to respiratory chemoreflex. In the present study, we found that TASK1 and TASK3 were expressed in orexin neurons. Blocking TASKs or microinjecting acid artificial cerebrospinal fluid (ACSF) in the LH stimulated breathing. In contrast, alkaline ACSF inhibited breathing, which was attenuated by blocking TASK1. Damage of orexin neurons attenuated the stimulatory effect on respiration caused by microinjection of acid ACSF (at a pH of 6.5) or TASKs antagonists. The orexinA-positive fiber and orexin type 1 receptor (OX1R) neurons were located in the nucleus tractus solitarius (NTS). The exciting effect of acidosis in the LH on respiration was inhibited by blocking OX1R of the NTS. Taken together, we conclude that orexin neurons sense the extracellular pH change through TASKs and regulate respiration by projecting to the NTS.
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Affiliation(s)
- Xia Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China.,Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Ruijuan Guan
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Xiaomei Zhao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jun Chen
- Department of Pathology, Changzheng Hospital, Naval Military Medical University, Shanghai, China
| | - Danian Zhu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Linlin Shen
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention, Fudan University, Shanghai, China
| | - Nana Song
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
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13
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Wheeler JA, Tutrow KD, Ebenroth ES, Gaston B, Bandyopadhyay A. Heart failure is not a determinant of central sleep apnea in the pediatric population. Pediatr Pulmonol 2021; 56:1092-1102. [PMID: 33434409 PMCID: PMC8035286 DOI: 10.1002/ppul.25242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/20/2020] [Accepted: 12/13/2020] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES Adults with heart failure (HF) have high prevalence of central sleep apnea (CSA). While this has been repeatedly investigated in adults, there is a deficiency of similar research in pediatric populations. The goal of this study was to compare prevalence of CSA in children with and without HF and correlate central apneic events with heart function. METHODS Retrospective analysis of data from children with and without HF was conducted. Eligible children were less than 18 years old with echocardiogram and polysomnogram within 6 months of each other. Children were separated into groups with and without HF based on left ventricular ejection fraction (LVEF). Defining CSA as central apnea-hypopnea index (CAHI) more than 1/hour, the cohort was also classified into children with and without CSA for comparative study. RESULTS A total of 120 children (+HF: 19, -HF: 101) were included. The +HF group was younger, with higher prevalence of trisomy 21, muscular dystrophy, oromotor incoordination, and structural heart disease. The +HF group had lower apnea-hypopnea index (median: 3/hour vs. 8.6/hour) and lower central apnea index (CAI) (median: 0.2/hour vs. 0.55/hour). Prevalence of CSA was similar in both groups (p = .195). LogCAHI was inversely correlated to age (Pearson correlation coefficient: -0.245, p = .022). Children with CSA were younger and had higher prevalence of prematurity (40% vs. 5.3%). There was no significant difference in LVEF between children with and without CSA. After excluding children with prematurity, relationship between CAHI and age was no longer sustained. CONCLUSIONS In contrast to adults, there is no difference in prevalence of CSA in children with and without HF. Unlike in adults, LVEF does not correlate with CAI in children. Overall, it appears that central apneic events may be more a function of age and prematurity rather than of heart function.
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Affiliation(s)
| | | | - Eric S. Ebenroth
- Indiana University School of Medicine, Division of Pediatric Cardiology
| | - Benjamin Gaston
- Indiana University School of Medicine, Section of Pediatric Pulmonology, Allergy and Sleep Medicine
| | - Anuja Bandyopadhyay
- Indiana University School of Medicine, Section of Pediatric Pulmonology, Allergy and Sleep Medicine
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14
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Bellù R, Romantsik O, Nava C, de Waal KA, Zanini R, Bruschettini M. Opioids for newborn infants receiving mechanical ventilation. Cochrane Database Syst Rev 2021; 3:CD013732. [PMID: 33729556 PMCID: PMC8121090 DOI: 10.1002/14651858.cd013732.pub2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mechanical ventilation is a potentially painful and discomforting intervention that is widely used in neonatal intensive care. Newborn infants demonstrate increased sensitivity to pain, which may affect clinical and neurodevelopmental outcomes. The use of drugs that reduce pain might be important in improving survival and neurodevelopmental outcomes. OBJECTIVES To determine the benefits and harms of opioid analgesics for neonates (term or preterm) receiving mechanical ventilation compared to placebo or no drug, other opioids, or other analgesics or sedatives. SEARCH METHODS We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 9), in the Cochrane Library; MEDLINE via PubMed (1966 to 29 September 2020); Embase (1980 to 29 September 2020); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 29 September 2020). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. SELECTION CRITERIA We included randomised and quasi-randomised controlled trials comparing opioids to placebo or no drug, to other opioids, or to other analgesics or sedatives in newborn infants on mechanical ventilation. We excluded cross-over trials. We included term (≥ 37 weeks' gestational age) and preterm (< 37 weeks' gestational age) newborn infants on mechanical ventilation. We included any duration of drug treatment and any dosage given continuously or as bolus; we excluded studies that gave opioids to ventilated infants for procedures. DATA COLLECTION AND ANALYSIS For each of the included trials, we independently extracted data (e.g. number of participants, birth weight, gestational age, types of opioids) using Cochrane Effective Practice and Organisation of Care Group (EPOC) criteria and assessed the risk of bias (e.g. adequacy of randomisation, blinding, completeness of follow-up). We evaluated treatment effects using a fixed-effect model with risk ratio (RR) for categorical data and mean difference (MD) for continuous data. We used the GRADE approach to assess the certainty of evidence. MAIN RESULTS We included 23 studies (enrolling 2023 infants) published between 1992 and 2019. Fifteen studies (1632 infants) compared the use of morphine or fentanyl versus placebo or no intervention. Four studies included both term and preterm infants, and one study only term infants; all other studies included only preterm infants, with five studies including only very preterm infants. We are uncertain whether opioids have an effect on the Premature Infant Pain Profile (PIPP) Scale in the first 12 hours after infusion (MD -5.74, 95% confidence interval (CI) -6.88 to -4.59; 50 participants, 2 studies) and between 12 and 48 hours after infusion (MD -0.98, 95% CI -1.35 to -0.61; 963 participants, 3 studies) because of limitations in study design, high heterogeneity (inconsistency), and imprecision of estimates (very low-certainty evidence - GRADE). The use of morphine or fentanyl probably has little or no effect in reducing duration of mechanical ventilation (MD 0.23 days, 95% CI -0.38 to 0.83; 1259 participants, 7 studies; moderate-certainty evidence because of unclear risk of bias in most studies) and neonatal mortality (RR 1.12, 95% CI 0.80 to 1.55; 1189 participants, 5 studies; moderate-certainty evidence because of imprecision of estimates). We are uncertain whether opioids have an effect on neurodevelopmental outcomes at 18 to 24 months (RR 2.00, 95% CI 0.39 to 10.29; 78 participants, 1 study; very low-certainty evidence because of serious imprecision of the estimates and indirectness). Limited data were available for the other comparisons (i.e. two studies (54 infants) on morphine versus midazolam, three (222 infants) on morphine versus fentanyl, and one each on morphine versus diamorphine (88 infants), morphine versus remifentanil (20 infants), fentanyl versus sufentanil (20 infants), and fentanyl versus remifentanil (24 infants)). For these comparisons, no meta-analysis was conducted because outcomes were reported by one study. AUTHORS' CONCLUSIONS We are uncertain whether opioids have an effect on pain and neurodevelopmental outcomes at 18 to 24 months; the use of morphine or fentanyl probably has little or no effect in reducing the duration of mechanical ventilation and neonatal mortality. Data on the other comparisons planned in this review (opioids versus analgesics; opioids versus other opioids) are extremely limited and do not allow any conclusions. In the absence of firm evidence to support a routine policy, opioids should be used selectively - based on clinical judgement and evaluation of pain indicators - although pain measurement in newborns has limitations.
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Affiliation(s)
- Roberto Bellù
- Neonatal Intensive Care Unit, Ospedale "A. Manzoni", Lecco, Italy
| | - Olga Romantsik
- Department of Clinical Sciences Lund, Paediatrics, Lund University, Skåne University Hospital, Lund, Sweden
| | - Chiara Nava
- Neonatal Intensive Care Unit, Ospedale "A. Manzoni", Lecco, Italy
| | - Koert A de Waal
- Neonatology, John Hunter Children's Hospital, New Lambton, Australia
| | - Rinaldo Zanini
- Neonatal Intensive Care Unit, Ospedale "A. Manzoni", Lecco, Italy
| | - Matteo Bruschettini
- Department of Clinical Sciences Lund, Paediatrics, Lund University, Skåne University Hospital, Lund, Sweden
- Cochrane Sweden, Lund University, Skåne University Hospital, Lund, Sweden
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15
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Patterson KC, Kahanovitch U, Gonçalves CM, Hablitz JJ, Staruschenko A, Mulkey DK, Olsen ML. K ir 5.1-dependent CO 2 /H + -sensitive currents contribute to astrocyte heterogeneity across brain regions. Glia 2021; 69:310-325. [PMID: 32865323 PMCID: PMC8665280 DOI: 10.1002/glia.23898] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 07/24/2020] [Accepted: 07/26/2020] [Indexed: 09/19/2023]
Abstract
Astrocyte heterogeneity is an emerging concept in which astrocytes within or between brain regions show variable morphological and/or gene expression profiles that presumably reflect different functional roles. Recent evidence indicates that retrotrapezoid nucleus (RTN) astrocytes sense changes in tissue CO2/ H+ to regulate respiratory activity; however, mechanism(s) by which they do so remain unclear. Alterations in inward K+ currents represent a potential mechanism by which CO2 /H+ signals may be conveyed to neurons. Here, we use slice electrophysiology in rats of either sex to show that RTN astrocytes intrinsically respond to CO2 /H+ by inhibition of an inward rectifying potassium (Kir ) conductance and depolarization of the membrane, while cortical astrocytes do not exhibit such CO2 /H+ -sensitive properties. Application of Ba2+ mimics the effect of CO2 /H+ on RTN astrocytes as measured by reductions in astrocyte Kir -like currents and increased RTN neuronal firing. These CO2 /H+ -sensitive currents increase developmentally, in parallel to an increased expression in Kir 4.1 and Kir 5.1 in the brainstem. Finally, the involvement of Kir 5.1 in the CO2 /H+ -sensitive current was verified using a Kir5.1 KO rat. These data suggest that Kir inhibition by CO2 /H+ may govern the degree to which astrocytes mediate downstream chemoreceptive signaling events through cell-autonomous mechanisms. These results identify Kir channels as potentially important regional CO2 /H+ sensors early in development, thus expanding our understanding of how astrocyte heterogeneity may uniquely support specific neural circuits and behaviors.
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Affiliation(s)
- Kelsey C Patterson
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Uri Kahanovitch
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | | | - John J Hablitz
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Daniel K Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269, USA
| | - Michelle L Olsen
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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16
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Shi Y, Stornetta DS, Reklow RJ, Sahu A, Wabara Y, Nguyen A, Li K, Zhang Y, Perez-Reyes E, Ross RA, Lowell BB, Stornetta RL, Funk GD, Guyenet PG, Bayliss DA. A brainstem peptide system activated at birth protects postnatal breathing. Nature 2021; 589:426-430. [PMID: 33268898 PMCID: PMC7855323 DOI: 10.1038/s41586-020-2991-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 09/29/2020] [Indexed: 01/29/2023]
Abstract
Among numerous challenges encountered at the beginning of extrauterine life, the most celebrated is the first breath that initiates a life-sustaining motor activity1. The neural systems that regulate breathing are fragile early in development, and it is not clear how they adjust to support breathing at birth. Here we identify a neuropeptide system that becomes activated immediately after birth and supports breathing. Mice that lack PACAP selectively in neurons of the retrotrapezoid nucleus (RTN) displayed increased apnoeas and blunted CO2-stimulated breathing; re-expression of PACAP in RTN neurons corrected these breathing deficits. Deletion of the PACAP receptor PAC1 from the pre-Bötzinger complex-an RTN target region responsible for generating the respiratory rhythm-phenocopied the breathing deficits observed after RTN deletion of PACAP, and suppressed PACAP-evoked respiratory stimulation in the pre-Bötzinger complex. Notably, a postnatal burst of PACAP expression occurred in RTN neurons precisely at the time of birth, coinciding with exposure to the external environment. Neonatal mice with deletion of PACAP in RTN neurons displayed increased apnoeas that were further exacerbated by changes in ambient temperature. Our findings demonstrate that well-timed PACAP expression by RTN neurons provides an important supplementary respiratory drive immediately after birth and reveal key molecular components of a peptidergic neural circuit that supports breathing at a particularly vulnerable period in life.
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Affiliation(s)
- Yingtang Shi
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Daniel S. Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Robert J. Reklow
- Department of Physiology, Women & Children’s Health Research Institute, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Alisha Sahu
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Yvonne Wabara
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Ashley Nguyen
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Keyong Li
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Yong Zhang
- Department of Physiology, Women & Children’s Health Research Institute, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Edward Perez-Reyes
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Rachel A. Ross
- Beth Israel Deaconess Medical Center, Harvard University, Boston, MA, USA,McLean Hospital, Department of Psychiatry, Harvard Medical School, Belmont, MA, USA
| | - Bradford B. Lowell
- Beth Israel Deaconess Medical Center, Harvard University, Boston, MA, USA
| | - Ruth L. Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Gregory D. Funk
- Department of Physiology, Women & Children’s Health Research Institute, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Patrice G. Guyenet
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Douglas A. Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
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17
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Gauda EB, Conde S, Bassi M, Zoccal DB, Almeida Colombari DS, Colombari E, Despotovic N. Leptin: Master Regulator of Biological Functions that Affects Breathing. Compr Physiol 2020; 10:1047-1083. [PMID: 32941688 DOI: 10.1002/cphy.c190031] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Obesity is a global epidemic in developed countries accounting for many of the metabolic and cardiorespiratory morbidities that occur in adults. These morbidities include type 2 diabetes, sleep-disordered breathing (SDB), obstructive sleep apnea, chronic intermittent hypoxia, and hypertension. Leptin, produced by adipocytes, is a master regulator of metabolism and of many other biological functions including central and peripheral circuits that control breathing. By binding to receptors on cells and neurons in the brainstem, hypothalamus, and carotid body, leptin links energy and metabolism to breathing. In this comprehensive article, we review the central and peripheral locations of leptin's actions that affect cardiorespiratory responses during health and disease, with a particular focus on obesity, SDB, and its effects during early development. Obesity-induced hyperleptinemia is associated with centrally mediated hypoventilation with decrease CO2 sensitivity. On the other hand, hyperleptinemia augments peripheral chemoreflexes to hypoxia and induces sympathoexcitation. Thus, "leptin resistance" in obesity is relative. We delineate the circuits responsible for these divergent effects, including signaling pathways. We review the unique effects of leptin during development on organogenesis, feeding behavior, and cardiorespiratory responses, and how undernutrition and overnutrition during critical periods of development can lead to cardiorespiratory comorbidities in adulthood. We conclude with suggestions for future directions to improve our understanding of leptin dysregulation and associated clinical diseases and possible therapeutic targets. Lastly, we briefly discuss the yin and the yang, specifically the contribution of relative adiponectin deficiency in adults with hyperleptinemia to the development of metabolic and cardiovascular disease. © 2020 American Physiological Society. Compr Physiol 10:1047-1083, 2020.
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Affiliation(s)
- Estelle B Gauda
- Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Silvia Conde
- CEDOC, NOVA Medical School, Faculdade de Ciências Médicas, Lisboa, Portugal
| | - Mirian Bassi
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Daniel B Zoccal
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Debora Simoes Almeida Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Nikola Despotovic
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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18
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Goel D, Oei JL, Smyth J, Schindler T. Diaphragm-triggered non-invasive respiratory support in preterm infants. Cochrane Database Syst Rev 2020; 3:CD012935. [PMID: 32176939 PMCID: PMC7075711 DOI: 10.1002/14651858.cd012935.pub2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Diaphragm-triggered non-invasive respiratory support, commonly referred to as NIV-NAVA (non-invasive neurally adjusted ventilatory assist), uses the electrical activity of the crural diaphragm to trigger the start and end of a breath. It provides variable inspiratory pressure that is proportional to an infant's changing inspiratory effort. NIV-NAVA has the potential to provide effective, non-invasive, synchronised, multilevel support and may reduce the need for invasive ventilation; however, its effects on short- and long-term outcomes, especially in the preterm infant, are unclear. OBJECTIVES To assess the effectiveness and safety of diaphragm-triggered non-invasive respiratory support in preterm infants (< 37 weeks' gestation) when compared to other non-invasive modes of respiratory support (nasal intermittent positive pressure ventilation (NIPPV); nasal continuous positive airway pressure (nCPAP); high-flow nasal cannulae (HFNC)), and to assess preterm infants with birth weight less than 1000 grams or less than 28 weeks' corrected gestation at the time of intervention as a sub-group. SEARCH METHODS We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2019, Issue 5), MEDLINE via PubMed (1946 to 10 May 2019), Embase (1947 to 10 May 2019), and CINAHL (1982 to 10 May 2019). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials. SELECTION CRITERIA Randomised and quasi-randomised controlled trials that compared diaphragm-triggered non-invasive versus other non-invasive respiratory support in preterm infants. DATA COLLECTION AND ANALYSIS Two review authors independently selected trials, assessed trial quality and extracted data from included studies. We performed fixed-effect analyses and expressed treatment effects as mean difference (MD), risk ratio (RR), and risk difference (RD) with 95% confidence intervals (CIs). We used the generic inverse variance method to analyse specific outcomes for cross-over trials. We used the GRADE approach to assess the certainty of evidence. MAIN RESULTS There were two small randomised controlled trials including a total of 23 infants eligible for inclusion in the review. Only one trial involving 16 infants included in the analysis reported on either of the primary outcomes of the review. This found no difference in failure of modality between NIV-NAVA and NIPPV (RR 0.33, 95% CI 0.02 to 7.14; RD -0.13, 95% CI -0.41 to 0.16; 1 study, 16 infants; heterogeneity not applicable). Both trials reported on secondary outcomes of the review, specific for cross-over trials (total 22 infants; 1 excluded due to failure of initial modality). One study involving seven infants reported a significant reduction in maximum FiO₂ with NIV-NAVA compared to NIPPV (MD -4.29, 95% CI -5.47 to -3.11; heterogeneity not applicable). There was no difference in maximum electric activity of the diaphragm (Edi) signal between modalities (MD -1.75, 95% CI -3.75 to 0.26; I² = 0%) and a significant increase in respiratory rate with NIV-NAVA compared to NIPPV (MD 7.22, 95% CI 0.21 to 14.22; I² = 72%) on a meta-analysis of two studies involving a total of 22 infants. The included studies did not report on other outcomes of interest. AUTHORS' CONCLUSIONS Due to limited data and very low certainty evidence, we were unable to determine if diaphragm-triggered non-invasive respiratory support is effective or safe in preventing respiratory failure in preterm infants. Large, adequately powered randomised controlled trials are needed to determine if diaphragm-triggered non-invasive respiratory support in preterm infants is effective or safe.
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Affiliation(s)
- Dimple Goel
- Westmead HospitalNeonatal Intensive CareHawkesbury Rd & Darcy RoadWestmeadNSWAustralia2145
| | - Ju Lee Oei
- Royal Hospital for WomenNewborn CareBarker StreetRandwickNSWAustralia2031
| | - John Smyth
- Royal Hospital for WomenNewborn CareBarker StreetRandwickNSWAustralia2031
| | - Tim Schindler
- Royal Hospital for WomenNewborn CareBarker StreetRandwickNSWAustralia2031
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19
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Abstract
Air-breathing animals do not experience hyperoxia (inspired O2 > 21%) in nature, but preterm and full-term infants often experience hyperoxia/hyperoxemia in clinical settings. This article focuses on the effects of normobaric hyperoxia during the perinatal period on breathing in humans and other mammals, with an emphasis on the neural control of breathing during hyperoxia, after return to normoxia, and in response to subsequent hypoxic and hypercapnic challenges. Acute hyperoxia typically evokes an immediate ventilatory depression that is often, but not always, followed by hyperpnea. The hypoxic ventilatory response (HVR) is enhanced by brief periods of hyperoxia in adult mammals, but the limited data available suggest that this may not be the case for newborns. Chronic exposure to mild-to-moderate levels of hyperoxia (e.g., 30-60% O2 for several days to a few weeks) elicits several changes in breathing in nonhuman animals, some of which are unique to perinatal exposures (i.e., developmental plasticity). Examples of this developmental plasticity include hypoventilation after return to normoxia and long-lasting attenuation of the HVR. Although both peripheral and CNS mechanisms are implicated in hyperoxia-induced plasticity, it is particularly clear that perinatal hyperoxia affects carotid body development. Some of these effects may be transient (e.g., decreased O2 sensitivity of carotid body glomus cells) while others may be permanent (e.g., carotid body hypoplasia, loss of chemoafferent neurons). Whether the hyperoxic exposures routinely experienced by human infants in clinical settings are sufficient to alter respiratory control development remains an open question and requires further research. © 2020 American Physiological Society. Compr Physiol 10:597-636, 2020.
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Affiliation(s)
- Ryan W Bavis
- Department of Biology, Bates College, Lewiston, Maine, USA
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Continuous vital sign analysis for predicting and preventing neonatal diseases in the twenty-first century: big data to the forefront. Pediatr Res 2020; 87:210-220. [PMID: 31377752 PMCID: PMC6962536 DOI: 10.1038/s41390-019-0527-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/20/2019] [Accepted: 07/25/2019] [Indexed: 01/03/2023]
Abstract
In the neonatal intensive care unit (NICU), heart rate, respiratory rate, and oxygen saturation are vital signs (VS) that are continuously monitored in infants, while blood pressure is often monitored continuously immediately after birth, or during critical illness. Although changes in VS can reflect infant physiology or circadian rhythms, persistent deviations in absolute values or complex changes in variability can indicate acute or chronic pathology. Recent studies demonstrate that analysis of continuous VS trends can predict sepsis, necrotizing enterocolitis, brain injury, bronchopulmonary dysplasia, cardiorespiratory decompensation, and mortality. Subtle changes in continuous VS patterns may not be discerned even by experienced clinicians reviewing spot VS data or VS trends captured in the monitor. In contrast, objective analysis of continuous VS data can improve neonatal outcomes by allowing heightened vigilance or preemptive interventions. In this review, we provide an overview of the studies that have used continuous analysis of single or multiple VS, their interactions, and combined VS and clinical analytic tools, to predict or detect neonatal pathophysiology. We make the case that big-data analytics are promising, and with continued improvements, can become a powerful tool to mitigate neonatal diseases in the twenty-first century.
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21
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McDonald FB, Dempsey EM, O'Halloran KD. The impact of preterm adversity on cardiorespiratory function. Exp Physiol 2019; 105:17-43. [PMID: 31626357 DOI: 10.1113/ep087490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/15/2019] [Indexed: 12/16/2022]
Abstract
NEW FINDINGS What is the topic of this review? We review the influence of prematurity on the cardiorespiratory system and examine the common sequel of alterations in oxygen tension, and immune activation in preterm infants. What advances does it highlight? The review highlights neonatal animal models of intermittent hypoxia, hyperoxia and infection that contribute to our understanding of the effect of stress on neurodevelopment and cardiorespiratory homeostasis. We also focus on some of the important physiological pathways that have a modulatory role on the cardiorespiratory system in early life. ABSTRACT Preterm birth is one of the leading causes of neonatal mortality. Babies that survive early-life stress associated with immaturity have significant prevailing short- and long-term morbidities. Oxygen dysregulation in the first few days and weeks after birth is a primary concern as the cardiorespiratory system slowly adjusts to extrauterine life. Infants exposed to rapid alterations in oxygen tension, including exposures to hypoxia and hyperoxia, have altered redox balance and active immune signalling, leading to altered stress responses that impinge on neurodevelopment and cardiorespiratory homeostasis. In this review, we explore the clinical challenges posed by preterm birth, followed by an examination of the literature on animal models of oxygen dysregulation and immune activation in the context of early-life stress.
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Affiliation(s)
- Fiona B McDonald
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland.,Irish Centre for Fetal and Neonatal Translational Research (INFANT) Research Centre, University College Cork, Cork, Ireland
| | - Eugene M Dempsey
- Irish Centre for Fetal and Neonatal Translational Research (INFANT) Research Centre, University College Cork, Cork, Ireland.,Department of Paediatrics & Child Health, School of Medicine, College of Medicine & Health, Cork University Hospital, Wilton, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland.,Irish Centre for Fetal and Neonatal Translational Research (INFANT) Research Centre, University College Cork, Cork, Ireland
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22
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Guyenet PG, Stornetta RL, Souza GMPR, Abbott SBG, Shi Y, Bayliss DA. The Retrotrapezoid Nucleus: Central Chemoreceptor and Regulator of Breathing Automaticity. Trends Neurosci 2019; 42:807-824. [PMID: 31635852 DOI: 10.1016/j.tins.2019.09.002] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/28/2019] [Accepted: 09/05/2019] [Indexed: 12/15/2022]
Abstract
The ventral surface of the rostral medulla oblongata has been suspected since the 1960s to harbor central respiratory chemoreceptors [i.e., acid-activated neurons that regulate breathing to maintain a constant arterial PCO2 (PaCO2)]. The key neurons, a.k.a. the retrotrapezoid nucleus (RTN), have now been identified. In this review we describe their transcriptome, developmental lineage, and anatomical projections. We also review their contribution to CO2 homeostasis and to the regulation of breathing automaticity during sleep and wake. Finally, we discuss several mechanisms that contribute to the activation of RTN neurons by CO2in vivo: cell-autonomous effects of protons; paracrine effects of pH mediated by surrounding astrocytes and blood vessels; and excitatory inputs from other CO2-responsive CNS neurons.
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Affiliation(s)
- Patrice G Guyenet
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA.
| | - Ruth L Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - George M P R Souza
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Stephen B G Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Yingtang Shi
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
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23
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Niblock MM, Perez A, Broitman S, Jacoby B, Aviv E, Gilkey S. In utero development of fetal breathing movements in C57BL6 mice. Respir Physiol Neurobiol 2019; 271:103288. [PMID: 31505274 DOI: 10.1016/j.resp.2019.103288] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/06/2019] [Accepted: 09/05/2019] [Indexed: 11/18/2022]
Abstract
Fetuses of many species, including humans, breathe during development. This fetal breathing aids in lung development, strengthens respiratory muscles, and is posited to fine-tune the neural circuitry that drives breathing. Previous studies suggested that fetal breathing could begin as early as the fifteenth day of gestation in the mouse, but fetal breathing movements (FBMs) had not been observed in mice in utero. We aimed to determine if and when FBMs commence in mice and if they change over time. We examined unanesthetised pregnant C57BL6 mice with ultrasound beginning on the seventh day of gestation. We first reliably observed episodic FBMs in mice on embryonic day 16. FBMs were sporadic, clustered, or rhythmic, and their frequency increased with age. Ultrasound examination of FBMs in mice has great potential utility in the study of transgenic mouse models to help us understand the prenatal characteristics of breathing related human developmental disorders, including Congenital Central Hypoventilation Syndrome (CCHS) and apnea of prematurity.
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Affiliation(s)
- Mary M Niblock
- Department of Biology, Dickinson College, Carlisle, PA, United States; Neuroscience Program, Dickinson College, Carlisle, PA, United States.
| | - Alanis Perez
- Department of Biology, Dickinson College, Carlisle, PA, United States
| | - Shahar Broitman
- Neuroscience Program, Dickinson College, Carlisle, PA, United States
| | - Brigitte Jacoby
- Neuroscience Program, Dickinson College, Carlisle, PA, United States; Biochemistry and Molecular Biology Program, Dickinson College, Carlisle, PA, United States
| | - Elana Aviv
- Department of Biology, Dickinson College, Carlisle, PA, United States
| | - Sydney Gilkey
- Neuroscience Program, Dickinson College, Carlisle, PA, United States; Biochemistry and Molecular Biology Program, Dickinson College, Carlisle, PA, United States
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24
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Pilarski JQ, Leiter JC, Fregosi RF. Muscles of Breathing: Development, Function, and Patterns of Activation. Compr Physiol 2019; 9:1025-1080. [PMID: 31187893 DOI: 10.1002/cphy.c180008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review is a comprehensive description of all muscles that assist lung inflation or deflation in any way. The developmental origin, anatomical orientation, mechanical action, innervation, and pattern of activation are described for each respiratory muscle fulfilling this broad definition. In addition, the circumstances in which each muscle is called upon to assist ventilation are discussed. The number of "respiratory" muscles is large, and the coordination of respiratory muscles with "nonrespiratory" muscles and in nonrespiratory activities is complex-commensurate with the diversity of activities that humans pursue, including sleep (8.27). The capacity for speech and adoption of the bipedal posture in human evolution has resulted in patterns of respiratory muscle activation that differ significantly from most other animals. A disproportionate number of respiratory muscles affect the nose, mouth, pharynx, and larynx, reflecting the vital importance of coordinated muscle activity to control upper airway patency during both wakefulness and sleep. The upright posture has freed the hands from locomotor functions, but the evolutionary history and ontogeny of forelimb muscles pervades the patterns of activation and the forces generated by these muscles during breathing. The distinction between respiratory and nonrespiratory muscles is artificial, as many "nonrespiratory" muscles can augment breathing under conditions of high ventilator demand. Understanding the ontogeny, innervation, activation patterns, and functions of respiratory muscles is clinically useful, particularly in sleep medicine. Detailed explorations of how the nervous system controls the multiple muscles required for successful completion of respiratory behaviors will continue to be a fruitful area of investigation. © 2019 American Physiological Society. Compr Physiol 9:1025-1080, 2019.
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Affiliation(s)
- Jason Q Pilarski
- Department of Biological and Dental Sciences, Idaho State University Pocatello, Idaho, USA
| | - James C Leiter
- Department of Molecular and Systems Biology, The Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
| | - Ralph F Fregosi
- Departments of Physiology and Neuroscience, The University of Arizona, Tucson, Arizona, USA
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25
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Dennery PA, Di Fiore JM, Ambalavanan N, Bancalari E, Carroll JL, Claure N, Hamvas A, Hibbs AM, Indic P, Kemp J, Krahn KN, Lake D, Laposky A, Martin RJ, Natarajan A, Rand C, Schau M, Weese-Mayer DE, Zimmet AM, Moorman JR. Pre-Vent: the prematurity-related ventilatory control study. Pediatr Res 2019; 85:769-776. [PMID: 30733614 PMCID: PMC6503843 DOI: 10.1038/s41390-019-0317-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/10/2019] [Accepted: 01/16/2019] [Indexed: 01/08/2023]
Abstract
BACKGROUND The increasing incidence of bronchopulmonary dysplasia in premature babies may be due in part to immature ventilatory control, contributing to hypoxemia. The latter responds to ventilation and/or oxygen therapy, treatments associated with adverse sequelae. This is an overview of the Prematurity-Related Ventilatory Control Study which aims to analyze the under-utilized cardiorespiratory continuous waveform monitoring data to delineate mechanisms of immature ventilatory control in preterm infants and identify predictive markers. METHODS Continuous ECG, heart rate, respiratory, and oxygen saturation data will be collected throughout the NICU stay in 500 infants < 29 wks gestation across 5 centers. Mild permissive hypercapnia, and hyperoxia and/or hypoxia assessments will be conducted in a subcohort of infants along with inpatient questionnaires, urine, serum, and DNA samples. RESULTS Primary outcomes will be respiratory status at 40 wks and quantitative measures of immature breathing plotted on a standard curve for infants matched at 36-37 wks. Physiologic and/or biologic determinants will be collected to enhance the predictive model linking ventilatory control to outcomes. CONCLUSIONS By incorporating bedside monitoring variables along with biomarkers that predict respiratory outcomes we aim to elucidate individualized cardiopulmonary phenotypes and mechanisms of ventilatory control contributing to adverse respiratory outcomes in premature infants.
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Affiliation(s)
- Phyllis A. Dennery
- Brown University, Warren Alpert School of Medicine, Hasbro Children’s Hospital, Providence, RI,Address for Correspondence Phyllis A. Dennery, MD, Department of Pediatrics, Warren Alpert School of Medicine at Brown University, Office of the Chair, Hasbro Children’s Hospital, 593 Eddy Street, Suite 125 / Providence, RI 02903, (401) 444-5648,
| | - Juliann M. Di Fiore
- Case Western Reserve University, School of Medicine, Department of Pediatrics, University Hospitals: Rainbow Babies & Children’s Hospital, Division of Neonatology, Cleveland, OH
| | - Namasivayam Ambalavanan
- University of Alabama at Birmingham School of Med, Div. of Neonatology, Dept. Pediatrics Molecular and Cellular Pathology, and Cell, Developmental, and Integrative Biology, Birmingham, AL
| | - Eduardo Bancalari
- University of Miami Miller School of Medicine, Holtz Children’s Hospital - Jackson Memorial Medical Center, Division of Neonatology, Department of Pediatrics, Miami, FL
| | - John L. Carroll
- University of Arkansas for Medical Science, Department of Pediatrics, Little Rock, AR
| | - Nelson Claure
- University of Miami Miller School of Medicine, Holtz Children’s Hospital - Jackson Memorial Medical Center, Division of Neonatology, Department of Pediatrics, Miami, FL
| | - Aaron Hamvas
- Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children’s Hospital of Chicago, Stanley Manne Children’s Research Institute, Chicago, IL
| | - Anna Maria Hibbs
- Case Western Reserve University, School of Medicine, Department of Pediatrics, University Hospitals: Rainbow Babies & Children’s Hospital, Division of Neonatology, Cleveland, OH
| | - Premananda Indic
- University of Texas Tyler, Department of Electrical Engineering, University of Alabama at Birmingham School of Med, Div. of Neonatology, Dept. Pediatrics, Tyler, TX
| | - James Kemp
- Washington University School of Medicine in St. Louis, Department of Pediatrics, St. Louis, MO
| | - Katy N. Krahn
- University of Virginia School of Medicine, Division of Cardiovascular Medicine, Charlottesville, VA
| | - Douglas Lake
- University of Virginia School of Medicine, Division of Cardiovascular Medicine, Charlottesville, VA
| | - Aaron Laposky
- National Institute of Health, National Center of Sleep Disorders Research, Bethesda, MD
| | - Richard J. Martin
- Case Western Reserve University, School of Medicine, Department of Pediatrics, University Hospitals: Rainbow Babies & Children’s Hospital, Division of Neonatology, Cleveland, OH
| | - Aruna Natarajan
- Division of Lung Diseases, National Heart Lung and Blood Institute, National Institute of Health, Bethesda, MD
| | - Casey Rand
- Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children’s Hospital of Chicago, Stanley Manne Children’s Research Institute, Chicago, IL
| | - Molly Schau
- Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children’s Hospital of Chicago, Stanley Manne Children’s Research Institute, Chicago, IL
| | - Debra E. Weese-Mayer
- Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children’s Hospital of Chicago, Stanley Manne Children’s Research Institute, Chicago, IL
| | - Amanda M. Zimmet
- University of Virginia School of Medicine, Division of Cardiovascular Medicine, Charlottesville, VA
| | - J. Randall Moorman
- University of Virginia School of Medicine, Division of Cardiovascular Medicine, Charlottesville, VA
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26
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Polysomnography in Preterm Infants with Bronchopulmonary Dysplasia for Monitoring Sleep-Disordered Breathing and Pulmonary Reserve. CURRENT SLEEP MEDICINE REPORTS 2019. [DOI: 10.1007/s40675-019-00141-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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27
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Bavis RW, Millström AH, Kim SM, MacDonald CA, O'Toole CA, Asklof K, McDonough AB. Combined effects of intermittent hyperoxia and intermittent hypercapnic hypoxia on respiratory control in neonatal rats. Respir Physiol Neurobiol 2018; 260:70-81. [PMID: 30439529 DOI: 10.1016/j.resp.2018.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/27/2018] [Accepted: 11/08/2018] [Indexed: 01/28/2023]
Abstract
Chronic exposure to intermittent hyperoxia causes abnormal carotid body development and attenuates the hypoxic ventilatory response (HVR) in neonatal rats. We hypothesized that concurrent exposure to intermittent hypercapnic hypoxia would influence this plasticity. Newborn rats were exposed to alternating bouts of hypercapnic hypoxia (10% O2/6% CO2) and hyperoxia (30-40% O2) (5 cycles h-1, 24 h d-1) through 13-14 days of age; the experiment was run twice, once in a background of 21% O2 and once in a background of 30% O2 (i.e., "relative hyperoxia"). Hyperoxia had only small effects on carotid body development when combined with intermittent hypercapnic hypoxia: the carotid chemoafferent response to hypoxia was reduced, but this did not affect the HVR. In contrast, sustained exposure to 30% O2 reduced carotid chemoafferent activity and carotid body size which resulted in a blunted HVR. When given alone, chronic intermittent hypercapnic hypoxia increased carotid body size and reduced the hypercapnic ventilatory response but did not affect the HVR. Overall, it appears that intermittent hypercapnic hypoxia counteracted the effects of hyperoxia on the carotid body and prevented developmental plasticity of the HVR.
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Affiliation(s)
- Ryan W Bavis
- Department of Biology, Bates College, Lewiston, ME 04240 USA.
| | | | - Song M Kim
- Department of Biology, Bates College, Lewiston, ME 04240 USA
| | | | | | - Kendra Asklof
- Department of Biology, Bates College, Lewiston, ME 04240 USA
| | - Amy B McDonough
- Department of Biology, Bates College, Lewiston, ME 04240 USA
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28
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Dahl MJ, Bowen S, Aoki T, Rebentisch A, Dawson E, Pettet L, Emerson H, Yu B, Wang Z, Yang H, Zhang C, Presson AP, Joss-Moore L, Null DM, Yoder BA, Albertine KH. Former-preterm lambs have persistent alveolar simplification at 2 and 5 months corrected postnatal age. Am J Physiol Lung Cell Mol Physiol 2018; 315:L816-L833. [PMID: 30211655 PMCID: PMC6295507 DOI: 10.1152/ajplung.00249.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/29/2018] [Accepted: 09/02/2018] [Indexed: 12/29/2022] Open
Abstract
Preterm birth and mechanical ventilation (MV) frequently lead to bronchopulmonary dysplasia, the histopathological hallmark of which is alveolar simplification. How developmental immaturity and ongoing injury, repair, and remodeling impact completion of alveolar formation later in life is not known, in part because of lack of suitable animal models. We report a new model, using former-preterm lambs, to test the hypothesis that they will have persistent alveolar simplification later in life. Moderately preterm lambs (~85% gestation) were supported by MV for ~6 days before being transitioned from all respiratory support to become former-preterm lambs. Results are compared with term control lambs that were not ventilated, and between males (M) and females (F). Alveolar simplification was quantified morphometrically and stereologically at 2 mo (4 M, 4 F) or 5 mo (4 M, 6 F) corrected postnatal age (cPNA) compared with unventilated, age-matched term control lambs (4 M, 4 F per control group). These postnatal ages in sheep are equivalent to human postnatal ages of 1-2 yr and ~6 yr, respectively. Multivariable linear regression results showed that former-preterm lambs at 2 or 5 mo cPNA had significantly thicker distal airspace walls ( P < 0.001 and P < 0.009, respectively), lower volume density of secondary septa ( P < 0.007 and P < 0.001, respectively), and lower radial alveolar count ( P < 0.003 and P < 0.020, respectively) compared with term control lambs. Sex-specific differences were not detected. We conclude that moderate preterm birth and MV for ~6 days impedes completion of alveolarization in former-preterm lambs. This new model provides the opportunity to identify underlying pathogenic mechanisms that may reveal treatment approaches.
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Affiliation(s)
- Mar Janna Dahl
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Sydney Bowen
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Toshio Aoki
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Andrew Rebentisch
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Elaine Dawson
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Luke Pettet
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Haleigh Emerson
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Baifeng Yu
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Zhengming Wang
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Haixia Yang
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Chong Zhang
- Division of Epidemiology, Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Angela P Presson
- Division of Epidemiology, Department of Internal Medicine, University of Utah , Salt Lake City, Utah
- Division of Critical Care, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Lisa Joss-Moore
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Donald M Null
- Division of Neonatology, University of California , Davis, California
| | - Bradley A Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Kurt H Albertine
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
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29
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Pickett KL, Stein PS, Vincen-Brown MA, Pilarski JQ. Maturation of Breathing-Related Inhibitory Neurotransmission in the Medulla Oblongata of the Embryonic and Perinatal Zebra Finch (Taeniopygia guttata). Dev Neurobiol 2018; 78:1081-1096. [PMID: 30160056 DOI: 10.1002/dneu.22632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 07/07/2018] [Accepted: 07/08/2018] [Indexed: 11/05/2022]
Abstract
The medullary portion of the embryonic zebra finch hindbrain was isolated and superfused with physiologically relevant artificial cerebral spinal fluid. This in vitro preparation produced uninterrupted rhythmic episodes of neural activity via cranial nerve IX (glossopharyngeal) from embryonic day 4 (E4) through hatching on E14. Cranial nerve IX carries motor activity to the glottis during the inspiratory phase of breathing, and we focused on the role of synaptic inhibition during the embryonic and perinatal maturation of this branchiomotor outflow. We show that spontaneous neural activity (SNA) is first observed on E4 and temporally transforms as the embryo ages. To start, SNA is dependent on the excitatory actions of GABAA and glycine. As the embryo continues to develop, GABAergic and glycinergic neurotransmission take on a modulatory role, albeit an excitatory one, through E10. After that, data show that GABAergic and glycinergic neurotransmission switches to a phenotype consistent with inhibition, coincident with the onset of functional breathing. We also report that the inhibitory action of GABAergic and glycinergic receptor gating is not necessary for the spontaneous generation of branchiomotor motor rhythms in these birds near hatching. This is the first report focusing on the development of central breathing-related inhibitory neurotransmission in birds during the entire period of embryogenesis.
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Affiliation(s)
- Kaci L Pickett
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho, 83209-8007
| | - Paxton S Stein
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho, 83209-8007
| | | | - Jason Q Pilarski
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho, 83209-8007.,Dental Sciences, Idaho State University, Pocatello, Idaho, 83209-8007
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30
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Porzionato A, Macchi V, De Caro R. Central and peripheral chemoreceptors in sudden infant death syndrome. J Physiol 2018; 596:3007-3019. [PMID: 29645275 PMCID: PMC6068209 DOI: 10.1113/jp274355] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 03/20/2018] [Indexed: 11/08/2022] Open
Abstract
The pathogenesis of sudden infant death syndrome (SIDS) has been ascribed to an underlying biological vulnerability to stressors during a critical period of development. This paper reviews the main data in the literature supporting the role of central (e.g. retrotrapezoid nucleus, serotoninergic raphe nuclei, locus coeruleus, orexinergic neurons, ventral medullary surface, solitary tract nucleus) and peripheral (e.g. carotid body) chemoreceptors in the pathogenesis of SIDS. Clinical and experimental studies indicate that central and peripheral chemoreceptors undergo critical development during the initial postnatal period, consistent with the age range of SIDS (<1 year). Most of the risk factors for SIDS (gender, genetic factors, prematurity, hypoxic/hyperoxic stimuli, inflammation, perinatal exposure to cigarette smoke and/or substance abuse) may structurally and functionally affect the developmental plasticity of central and peripheral chemoreceptors, strongly suggesting the involvement of these structures in the pathogenesis of SIDS. Morphometric and neurochemical changes have been found in the carotid body and brainstem respiratory chemoreceptors of SIDS victims, together with functional signs of chemoreception impairment in some clinical studies. However, the methodological problems of SIDS research will have to be addressed in the future, requiring large and highly standardized case series. Up-to-date autopsy protocols should be produced, involving substantial, and exhaustive sampling of all potentially involved structures (including peripheral arterial chemoreceptors). Morphometric approaches should include unbiased stereological methods with three-dimensional probes. Prospective clinical studies addressing functional tests and risk factors (including genetic traits) would probably be the gold standard, allowing markers of intrinsic or acquired vulnerability to be properly identified.
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Affiliation(s)
- Andrea Porzionato
- Section of Anatomy, Department of NeuroscienceUniversity of PadovaItaly
| | - Veronica Macchi
- Section of Anatomy, Department of NeuroscienceUniversity of PadovaItaly
| | - Raffaele De Caro
- Section of Anatomy, Department of NeuroscienceUniversity of PadovaItaly
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31
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Stojanovska V, Miller SL, Hooper SB, Polglase GR. The Consequences of Preterm Birth and Chorioamnionitis on Brainstem Respiratory Centers: Implications for Neurochemical Development and Altered Functions by Inflammation and Prostaglandins. Front Cell Neurosci 2018; 12:26. [PMID: 29449803 PMCID: PMC5799271 DOI: 10.3389/fncel.2018.00026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/17/2018] [Indexed: 11/16/2022] Open
Abstract
Preterm birth is a major cause for neonatal morbidity and mortality, and is frequently associated with adverse neurological outcomes. The transition from intrauterine to extrauterine life at birth is particularly challenging for preterm infants. The main physiological driver for extrauterine transition is the establishment of spontaneous breathing. However, preterm infants have difficulty clearing lung liquid, have insufficient surfactant levels, and underdeveloped lungs. Further, preterm infants have an underdeveloped brainstem, resulting in reduced respiratory drive. These factors facilitate the increased requirement for respiratory support. A principal cause of preterm birth is intrauterine infection/inflammation (chorioamnionitis), and infants with chorioamnionitis have an increased risk and severity of neurological damage, but also demonstrate impaired autoresuscitation capacity and prevalent apnoeic episodes. The brainstem contains vital respiratory centers which provide the neural drive for breathing, but the impact of preterm birth and/or chorioamnionitis on this brain region is not well understood. The aim of this review is to provide an overview of the role and function of the brainstem respiratory centers, and to highlight the proposed mechanisms of how preterm birth and chorioamnionitis may affect central respiratory functions.
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Affiliation(s)
- Vanesa Stojanovska
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Suzanne L Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
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Goel D, Oei JL, Smyth J, Schindler T. Diaphragm-triggered non-invasive respiratory support for preventing respiratory failure in preterm infants. Hippokratia 2018. [DOI: 10.1002/14651858.cd012935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Dimple Goel
- Westmead Hospital; Neonatal Intensive care; Hawkesbury Rd & Darcy Road Westmead NSW Australia 2145
| | - Ju Lee Oei
- Royal Hospital for Women; Newborn Care; Barker Street Randwick NSW Australia 2031
| | - John Smyth
- Royal Hospital for Women; Newborn Care; Barker Street Randwick NSW Australia 2031
| | - Tim Schindler
- Royal Hospital for Women; Newborn Care; Barker Street Randwick NSW Australia 2031
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FEATURES OF CARDIORESPIRATORY ADAPTATION OF LATER PRETERM INFANTS IN THE EARLY NEONATAL PERIOD. WORLD OF MEDICINE AND BIOLOGY 2018. [DOI: 10.26724/2079-8334-2018-4-66-100-103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Quintero MC, Putnam RW, Cordovez JM. Theoretical perspectives on central chemosensitivity: CO2/H+-sensitive neurons in the locus coeruleus. PLoS Comput Biol 2017; 13:e1005853. [PMID: 29267284 PMCID: PMC5755939 DOI: 10.1371/journal.pcbi.1005853] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 01/05/2018] [Accepted: 10/26/2017] [Indexed: 12/18/2022] Open
Abstract
Central chemoreceptors are highly sensitive neurons that respond to changes in pH and CO2 levels. An increase in CO2/H+ typically reflects a rise in the firing rate of these neurons, which stimulates an increase in ventilation. Here, we present an ionic current model that reproduces the basic electrophysiological activity of individual CO2/H+-sensitive neurons from the locus coeruleus (LC). We used this model to explore chemoreceptor discharge patterns in response to electrical and chemical stimuli. The modeled neurons showed both stimulus-evoked activity and spontaneous activity under physiological parameters. Neuronal responses to electrical and chemical stimulation showed specific firing patterns of spike frequency adaptation, postinhibitory rebound, and post-stimulation recovery. Conversely, the response to chemical stimulation alone (based on physiological CO2/H+ changes), in the absence of external depolarizing stimulation, showed no signs of postinhibitory rebound or post-stimulation recovery, and no depolarizing sag. A sensitivity analysis for the firing-rate response to the different stimuli revealed that the contribution of an applied stimulus current exceeded that of the chemical signals. The firing-rate response increased indefinitely with injected depolarizing current, but reached saturation with chemical stimuli. Our computational model reproduced the regular pacemaker-like spiking pattern, action potential shape, and most of the membrane properties that characterize CO2/H+-sensitive neurons from the locus coeruleus. This validates the model and highlights its potential as a tool for studying the cellular mechanisms underlying the altered central chemosensitivity present in a variety of disorders such as sudden infant death syndrome, depression, and anxiety. In addition, the model results suggest that small external electrical signals play a greater role in determining the chemosensitive response to changes in CO2/H+ than previously thought. This highlights the importance of considering electrical synaptic transmission in studies of intrinsic chemosensitivity. The sensory mechanism by which changes in CO2 and H+ levels are detected in the brain is known as central chemoreception. Altered chemoreception is common to a wide variety of clinical conditions, including sleep apnea, sudden infant death syndrome, hyperventilation, depression, anxiety and asthma. In addition, CO2/H+-sensitive neurons are present in some regions of the brain that have been identified as drug targets for the treatment of anxiety and panic disorders. We are interested in understanding the cellular mechanisms that determine and modulate the behavior of these neurons. We previously investigated possible mechanisms underlying their behavior in rats to elucidate whether they respond to changes in intracellular or extracellular pH, CO2, or a combination of these stimuli. To study the roles that signals and ion channel targets play in individual neurons we develop mathematical models that simulate their electrochemical behavior and their responses to hypercapnic and/or acidotic stimuli. Nowadays, we are focused on using computational tools to explore the firing pattern of such neurons in response to chemical (CO2/H+) and electrical (synaptic) stimulation. Our results reveal significant effects of electrical stimulation on the responses of brainstem neurons and highlight the importance of considering synaptic transmission in experimental studies of chemosensitivity.
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Affiliation(s)
- Maria C. Quintero
- Biomedical Engineering Department, Universidad de Los Andes, Bogotá, Colombia
- * E-mail: (MQ); (JC)
| | - Robert W. Putnam
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, United States of America
| | - Juan M. Cordovez
- Biomedical Engineering Department, Universidad de Los Andes, Bogotá, Colombia
- * E-mail: (MQ); (JC)
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Joosten K, de Goederen R, Pijpers A, Allegaert K. Sleep related breathing disorders and indications for polysomnography in preterm infants. Early Hum Dev 2017; 113:114-119. [PMID: 28711234 DOI: 10.1016/j.earlhumdev.2017.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
There is a range of breathing problems which occur and may persist in preterm infants, such as central apneas, obstructive apneas and periodic breathing. Preterm infants may also suffer from respiratory distress syndrome and chronic lung disease necessitating prolonged use of oxygen therapy after discharge from the hospital. Due to these persistent breathing pattern abnormalities in preterm infants, there is a higher risk of altered sleep and apparent life threatening events. Polysomnography can be a helpful tool to identify those infants who have abnormalities in their breathing pattern, to identify those infants who have an increased risk to get a sleep related breathing event at home and to decide about the discontinuation of oxygen therapy.
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Affiliation(s)
- Koen Joosten
- Erasmus MC, Sophia Children's Hospital, Pediatric Intensive Care, Rotterdam, The Netherlands.
| | - Robbin de Goederen
- Dutch Craniofacial Center, Department of Plastic, Reconstructive and Hand Surgery, Sophia Children's Hospital - Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Angelique Pijpers
- Kempenhaeghe Academic Center for Epileptology, Sleep Medicine and Neurocognition, Heeze, The Netherlands
| | - Karel Allegaert
- Department of Pediatric Surgery, Erasmus University Medical Center - Sophia, Rotterdam, The Netherlands; Department of Development and Regeneration, KU Leuven, Leuven, Belgium
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Kouchi H, Uppari N, Joseph V, Bairam A. Sex-specific respiratory effects of acute and chronic caffeine administration in newborn rats. Respir Physiol Neurobiol 2017; 240:8-16. [DOI: 10.1016/j.resp.2017.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/19/2017] [Accepted: 01/28/2017] [Indexed: 01/01/2023]
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More S, Bicout D, Botner A, Butterworth A, Calistri P, Depner K, Edwards S, Garin-Bastuji B, Good M, Gortazar Schmidt C, Michel V, Miranda MA, Saxmose Nielsen S, Velarde A, Thulke HH, Sihvonen L, Spoolder H, Stegeman JA, Raj M, Willeberg P, Candiani D, Winckler C. Animal welfare aspects in respect of the slaughter or killing of pregnant livestock animals (cattle, pigs, sheep, goats, horses). EFSA J 2017; 15:e04782. [PMID: 32625488 PMCID: PMC7009911 DOI: 10.2903/j.efsa.2017.4782] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
This scientific opinion addresses animal welfare aspects of slaughtering of livestock pregnant animals. Term of Reference (ToR) 1 requested assessment of the prevalence of animals slaughtered in a critical developmental stage of gestation when the livestock fetuses might experience negative affect. Limited data on European prevalence and related uncertainties necessitated a structured expert knowledge elicitation (EKE) exercise. Estimated median percentages of animals slaughtered in the last third of gestation are 3%, 1.5%, 0.5%, 0.8% and 0.2% (dairy cows, beef cattle, pigs, sheep and goats, respectively). Pregnant animals may be sent for slaughter for health, welfare, management and economic reasons (ToR2); there are also reasons for farmers not knowing that animals sent for slaughter are pregnant. Measures to reduce the incidence are listed. ToR3 asked whether livestock fetuses can experience pain and other negative affect. The available literature was reviewed and, at a second multidisciplinary EKE meeting, judgements and uncertainty were elicited. It is concluded that livestock fetuses in the last third of gestation have the anatomical and neurophysiological structures required to experience negative affect (with 90-100% likelihood). However, there are two different possibilities whether they perceive negative affect. It is more probable that the neurophysiological situation does not allow for conscious perception (with 66-99% likelihood) because of brain inhibitory mechanisms. There is also a less probable situation that livestock fetuses can experience negative affect (with 1-33% likelihood) arising from differences in the interpretation of the fetal electroencephalogram, observed responses to external stimuli and the possibility of fetal learning. Regarding methods to stun and kill livestock fetuses at slaughter (ToR4), sets of scenarios and respective actions take account of both the probable and less probable situation regarding fetal ability for conscious perception. Finally, information was collated on methods to establish the dam's gestational stage based on physical features of livestock fetuses (ToR5).
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Developmental plasticity in the neural control of breathing. Exp Neurol 2017; 287:176-191. [DOI: 10.1016/j.expneurol.2016.05.032] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/13/2016] [Accepted: 05/26/2016] [Indexed: 12/14/2022]
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Acid-sensing ion channels are expressed in the ventrolateral medulla and contribute to central chemoreception. Sci Rep 2016; 6:38777. [PMID: 27934921 PMCID: PMC5146928 DOI: 10.1038/srep38777] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 11/14/2016] [Indexed: 12/30/2022] Open
Abstract
The role of acid-sensing ion channels (ASICs) in the ventrolateral medulla (VLM) remains uncertain. Here, we found that ASIC1a and ASIC2 are widely expressed in rat medulla, and the expression level is higher at neonatal stage as compared to adult stage. The two ASIC subunits co-localized in medualla neurons. Furthermore, pH reduction triggered typical ASIC-type currents in the medulla, including the VLM. These currents showed a pH50 value of 6.6 and were blocked by amiloride. Based on their sensitivity to psalmotoxin 1 (PcTx1) and zinc, homomeric ASIC1a and heteromeric ASIC1a/2 channels were likely responsible for acid-mediated currents in the mouse medulla. ASIC currents triggered by pH 5 disappeared in the VLM neurons from ASIC1−/−, but not ASIC2−/− mice. Activation of ASICs in the medulla also triggered neuronal excitation. Moreover, microinjection of artificial cerebrospinal fluid at a pH of 6.5 into the VLM increased integrated phrenic nerve discharge, inspiratory time and respiratory drive in rats. Both amiloride and PcTx1 inhibited the acid-induced stimulating effect on respiration. Collectively, our data suggest that ASICs are highly expressed in the medulla including the VLM, and activation of ASICs in the VLM contributes to central chemoreception.
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Clinical associations with immature breathing in preterm infants: part 2-periodic breathing. Pediatr Res 2016; 80:28-34. [PMID: 27002984 PMCID: PMC4929034 DOI: 10.1038/pr.2016.58] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/19/2016] [Indexed: 11/13/2022]
Abstract
BACKGROUND Periodic breathing (PB) is a normal immature breathing pattern in neonates that, if extreme, may be associated with pathologic conditions. METHODS We used our automated PB detection system to analyze all bedside monitor chest impedance data on all infants <35 wk' gestation in the University of Virginia Neonatal Intensive Care Unit from 2009-2014 (n = 1,211). Percent time spent in PB was calculated hourly (>50 infant-years' data). Extreme PB was identified as a 12-h period with PB >6 SDs above the mean for gestational age (GA) and postmenstrual age and >10% time in PB. RESULTS PB increased with GA, with the highest amount in infants 30-33 wk' GA at about 2 wk' chronologic age. Extreme PB was identified in 76 infants and in 45% was temporally associated with clinical events including infection or necrotizing enterocolitis (NEC), immunizations, or caffeine discontinuation. In 8 out of 28 cases of septicemia and 10 out of 21 cases of NEC, there was a >2-fold increase in %PB over baseline on the day prior to diagnosis. CONCLUSION Infants <35 wk GA spend, on average, <6% of the time in PB. An acute increase in PB may reflect illness or physiological stressors or may occur without any apparent clinical event.
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Clinical associations of immature breathing in preterm infants: part 1-central apnea. Pediatr Res 2016; 80:21-7. [PMID: 26959485 PMCID: PMC5015591 DOI: 10.1038/pr.2016.43] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 12/15/2015] [Indexed: 11/08/2022]
Abstract
BACKGROUND Apnea of prematurity (AOP) is nearly universal among very preterm infants, but neither the apnea burden nor its clinical associations have been systematically studied in a large consecutive cohort. METHODS We analyzed continuous bedside monitor chest impedance and electrocardiographic waveforms and oxygen saturation data collected on all neonatal intensive care unit (NICU) patients <35 wk gestation from 2009 to 2014 (n = 1,211; >50 infant-years of data). Apneas, with bradycardia and desaturation (ABDs), defined as central apnea ≥10 s associated with both bradycardia <100 bpm and oxygen desaturation <80%, were identified using a validated automated algorithm. RESULTS Number and duration of apnea events decreased with increasing gestational age (GA) and postmenstrual age (PMA). ABDs were more frequent in infants <31 wk GA at birth but were not more frequent in those with severe retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), or severe intraventricular hemorrhage (IVH) after accounting for GA. In the day before diagnosis of late-onset septicemia and necrotizing enterocolitis, ABD events were increased in some infants. Many infants continued to experience short ABD events in the week prior to discharge home. CONCLUSION Frequency of apnea events is a function of GA and PMA in infants born preterm, and increased apnea is associated with acute but not with chronic pathologic conditions.
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Kesavan K, Frank P, Cordero DM, Benharash P, Harper RM. Neuromodulation of Limb Proprioceptive Afferents Decreases Apnea of Prematurity and Accompanying Intermittent Hypoxia and Bradycardia. PLoS One 2016; 11:e0157349. [PMID: 27304988 PMCID: PMC4909267 DOI: 10.1371/journal.pone.0157349] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/28/2016] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Apnea of Prematurity (AOP) is common, affecting the majority of infants born at <34 weeks gestational age. Apnea and periodic breathing are accompanied by intermittent hypoxia (IH). Animal and human studies demonstrate that IH exposure contributes to multiple pathologies, including retinopathy of prematurity (ROP), injury to sympathetic ganglia regulating cardiovascular action, impaired pancreatic islet cell and bone development, cerebellar injury, and neurodevelopmental disabilities. Current standard of care for AOP/IH includes prone positioning, positive pressure ventilation, and methylxanthine therapy; these interventions are inadequate, and not optimal for early development. OBJECTIVE The objective is to support breathing in premature infants by using a simple, non-invasive vibratory device placed over limb proprioceptor fibers, an intervention using the principle that limb movements trigger reflexive facilitation of breathing. METHODS Premature infants (23-34 wks gestational age), with clinical evidence of AOP/IH episodes were enrolled 1 week after birth. Caffeine treatment was not a reason for exclusion. Small vibration devices were placed on one hand and one foot and activated in 6 hour ON/OFF sequences for a total of 24 hours. Heart rate, respiratory rate, oxygen saturation (SpO2), and breathing pauses were continuously collected. RESULTS Fewer respiratory pauses occurred during vibration periods, relative to baseline (p<0.005). Significantly fewer SpO2 declines occurred with vibration (p<0.05), relative to control periods. Significantly fewer bradycardic events occurred during vibration periods, relative to no vibration periods (p<0.05). CONCLUSIONS In premature neonates, limb proprioceptive stimulation, simulating limb movement, reduces breathing pauses and IH episodes, and lowers the number of bradycardic events that accompany aberrant breathing episodes. This low-cost neuromodulatory procedure has the potential to provide a non-invasive intervention to reduce apnea, bradycardia and intermittent hypoxia in premature neonates. TRIAL REGISTRATION ClinicalTrials.gov NCT02641249.
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Affiliation(s)
- Kalpashri Kesavan
- Pediatrics, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
| | - Paul Frank
- Cardiothoracic Surgery, University of California Los Angeles, Los Angeles, California, United States of America
| | - Daniella M. Cordero
- Pediatrics, University of California Los Angeles, Los Angeles, California, United States of America
| | - Peyman Benharash
- Surgery, Harbor-UCLA, Los Angeles, California, United States of America
| | - Ronald M. Harper
- Neurobiology, University of California Los Angeles, Los Angeles, California, United States of America
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Oñatibia-Astibia A, Martínez-Pinilla E, Franco R. The potential of methylxanthine-based therapies in pediatric respiratory tract diseases. Respir Med 2016; 112:1-9. [PMID: 26880379 DOI: 10.1016/j.rmed.2016.01.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/07/2015] [Accepted: 01/28/2016] [Indexed: 02/03/2023]
Abstract
Caffeine, theophylline and theobromine are the most known methylxanthines as they are present in coffee, tea and/or chocolate. In the last decades, a huge experimental effort has been devoted to get insight into the variety of actions that these compounds exert in humans. From such knowledge it is known that methylxanthines have a great potential in prevention, therapy and/or management of a variety of diseases. The benefits of methylxanthine-based therapies in the apnea of prematurity and their translational potential in pediatric affections of the respiratory tract are here presented.
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Affiliation(s)
| | - Eva Martínez-Pinilla
- Neuroscience Department, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain.
| | - Rafael Franco
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain; CIBERNED, Centro de Investigación en Red, Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, 28049 Madrid, Spain; Institute of Biomedicine of the University of Barcelona, IBUB, 08028, Barcelona, Spain.
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Smith VC, Kelty-Stephen D, Qureshi Ahmad M, Mao W, Cakert K, Osborne J, Paydarfar D. Stochastic Resonance Effects on Apnea, Bradycardia, and Oxygenation: A Randomized Controlled Trial. Pediatrics 2015; 136:e1561-8. [PMID: 26598451 PMCID: PMC4657600 DOI: 10.1542/peds.2015-1334] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To evaluate the effect of stochastic resonance (SR) stimulation on preterm infant oxygen desaturation, bradycardia, and apnea events. We hypothesized that SR stimulation will reduce these events. METHODS This was a randomized crossover study conducted from April 2012 to July 2014. Eligible preterm infants were not receiving ventilation support and had at least 1 clinically documented apnea, bradycardia, and/or oxygen desaturation event. The 3 outcome variables were as follows: oxygen desaturation, bradycardia, and apnea events. Infants received up to two 3- or 4-hour intervention periods of 30-minute alternating intervals of SR stimulation and no SR stimulation. The first intervention period was randomly assigned to begin with SR stimulation either on or off, whereas the next intervention period automatically began with the opposite on/off state. We compared the SR stimulation "on" periods with the SR stimulation "off" periods with each infant serving as his or her own control. RESULTS The sample consisted of 36 infants with a mean (±SD) gestational age of 30.5 ± 3 weeks and a birth weight of 1409 ± 450 g. SR stimulation decreased the number of apneic events by 50%. SR stimulation ameliorated every aspect of clinically significant oxygen desaturation events, with a 20% to 35% decrease in the number, duration, and intensity of oxygen desaturation events when SR stimulation was on. Also, SR stimulation produced a nearly 20% reduction in the intensity of bradycardia events. CONCLUSIONS SR stimulation may be a noninvasive and nonpharmacologic treatment option for apnea, oxygen desaturation, and some aspects of bradycardia in premature infants.
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Affiliation(s)
- Vincent C. Smith
- Department of Neonatology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Damian Kelty-Stephen
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts;,Grinnell College, Grinnell, Iowa; and
| | - Mona Qureshi Ahmad
- Department of Neonatology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts;,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts
| | - Wenyang Mao
- Department of Neonatology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Kelly Cakert
- Department of Neonatology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts;,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts
| | - John Osborne
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts
| | - David Paydarfar
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts;,Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts
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Ren J, Ding X, Greer JJ. Ampakines Enhance Weak Endogenous Respiratory Drive and Alleviate Apnea in Perinatal Rats. Am J Respir Crit Care Med 2015; 191:704-10. [DOI: 10.1164/rccm.201410-1898oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Amin SB, Wang H. Unbound unconjugated hyperbilirubinemia is associated with central apnea in premature infants. J Pediatr 2015; 166:571-5. [PMID: 25596965 PMCID: PMC4344891 DOI: 10.1016/j.jpeds.2014.12.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 10/24/2014] [Accepted: 12/02/2014] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To evaluate whether jaundice, indexed by unbound bilirubin (UB), is associated with central apnea in premature infants. STUDY DESIGN A prospective observational study was performed with 27-33 weeks' gestational age infants who were not requiring either mechanical ventilation or noninvasive ventilation with continuous positive airway pressure beyond 24 hours after birth. Infants with congenital infections, chromosomal disorders, craniofacial anomalies, and/or family history of hearing loss were excluded. Total serum bilirubin and UB were measured twice daily during the first postnatal week and then when clinically indicated. Central apnea was evaluated by visual inspection of continuous, electronic cardiorespiratory recordings until 2 weeks of age. RESULTS One hundred infants were subdivided into 2 groups via median peak UB level: the high UB group (greater than median) and low UB group (less than median). The high UB group had an increased frequency of apnea events during the first 2 weeks compared with infants in the low UB group. After we controlled for confounders, the high UB group had more events of apnea during the first 2 postnatal weeks compared with the low UB group (incidence rate ratio: 1.9, 95% CI 1.2-3.2). CONCLUSIONS Our findings suggest that jaundice, as indexed by UB, is associated with central apnea in premature infants.
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Affiliation(s)
- Sanjiv B Amin
- Division of Neonatology, Department of Pediatrics, The University of Rochester School of Medicine and Dentistry, Rochester, NY.
| | - Hongyue Wang
- Department of Biostatistics, The University of Rochester School of Medicine and Dentistry
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Jeong K, Kim HS, Song ES, Choi YY. Comparison between Caffeine and Theophylline Therapy for Apnea of Prematurity. NEONATAL MEDICINE 2015. [DOI: 10.5385/nm.2015.22.1.14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Kumi Jeong
- Department of Pediatrics, Chonnam National University Hospital, Gwangju, Korea
| | - Ho Sung Kim
- Department of Pediatrics, Chonnam National University Hospital, Gwangju, Korea
| | - Eun Song Song
- Department of Pediatrics, Chonnam National University Hospital, Gwangju, Korea
| | - Young Youn Choi
- Department of Pediatrics, Chonnam National University Hospital, Gwangju, Korea
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Cummings KJ. Interaction of central and peripheral chemoreflexes in neonatal mice: evidence for hypo-addition. Respir Physiol Neurobiol 2014; 203:75-81. [PMID: 25192642 DOI: 10.1016/j.resp.2014.08.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 10/24/2022]
Abstract
The potential for interaction between the peripheral (PCR) and central (CCR) chemoreflexes has not been studied in the neonatal period, when breathing is inherently unstable. Based on recent work in adult rodents, this study addresses the hypothesis that in neonatal mice there is a hypoadditive interaction between the chemoreflexes. To test this, a mask-pneumotach system was used to expose postnatal day (P) 11-12 mouse pups to square-wave hyperoxia (100% O2; n=8) or hypoxia (10% O2; n=11), administered in normocapnic conditions (inspired CO2 (FICO2)=0.001-0.005), or following an episode of re-breathing to increase FICO2 by 0.015-0.02. The immediate (i.e. PCR-mediated) responses of frequency (fB), tidal volume (VT) and ventilation (V˙E) to square-wave hyperoxia and hypoxia were assessed. When given in a normocapnic background, hyperoxia induced an immediate (within the first 20 breaths, or ∼6s) but transient fall in fB (-46±9breaths/min) and V˙E (-149±41μlmin(-1)g(-1)) (P<0.001 for both), with no effect on VT. In contrast, hyperoxia had no influence on breathing when it was administered following re-breathing. Similarly, the hypoxia-induced increase in fB was greater when applied under normocapnic conditions (50±8breaths/min) then when applied following re-breathing (21±5breaths/min) (P=0.02). These data demonstrate a hypo-additive interaction between the PCR and CCR with respect to the immediate frequency response to inhibition or excitation of the PCR. Hypoaddition of the chemoreflexes could cause or mitigate neonatal apnea, depending on the prevailing PCO2.
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Affiliation(s)
- Kevin J Cummings
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
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49
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Kidder IJ, Mudery JA, Fiona Bailey E. Neural drive to respiratory muscles in the spontaneously breathing rat pup. Respir Physiol Neurobiol 2014; 202:64-70. [DOI: 10.1016/j.resp.2014.07.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/17/2014] [Accepted: 07/31/2014] [Indexed: 12/22/2022]
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50
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Abstract
Breathing movements have been demonstrated in the fetuses of every mammalian species investigated and are a critical component of normal fetal development. The classic sheep preparations instrumented for chronic fetal monitoring determined that fetal breathing movements (FBMs) occur in aggregates interspersed with long periods of quiescence that are strongly associated with neurophysiological state. The fetal sheep model also provided data regarding the neurochemical modulation of behavioral state and FBMs under a variety of in utero conditions. Subsequently, in vitro rodent models have been developed to advance our understanding of cellular, synaptic, network, and more detailed neuropharmacological aspects of perinatal respiratory neural control. This includes the ontogeny of the inspiratory rhythm generating center, the preBötzinger complex (preBötC), and the anatomical and functional development of phrenic motoneurons (PMNs) and diaphragm during the perinatal period. A variety of newborn animal models and studies of human infants have provided insights into age-dependent changes in state-dependent respiratory control, responses to hypoxia/hypercapnia and respiratory pathologies.
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Affiliation(s)
- John J Greer
- Department of Physiology, Centre for Neuroscience, Women and Children Health Research Institute, University of Alberta, Edmonton, Alberta, Canada.
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