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Koucký V, Koucká P, Koucký M. Hyperoxic ventilatory response in infants is related to nocturnal hypoxaemia. ERJ Open Res 2024; 10:00512-2023. [PMID: 38333650 PMCID: PMC10851931 DOI: 10.1183/23120541.00512-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/22/2023] [Indexed: 02/10/2024] Open
Abstract
Background The carotid bodies primarily serve as oxaemia sensors that affect tidal breathing. Their function has not yet been studied in infants with nocturnal hypoxaemia. This cross-sectional study aimed to characterise the hyperoxic ventilatory response (HVR) in infants and its relationship to nocturnal hypoxaemia. Methods The HVR was analysed in term infants aged <24 months with childhood interstitial lung disease (chILD), those with severe recurrent wheezing (wheeze), and nonrespiratory controls. The HVR timing was characterised using hyperoxia response time (HRT1), and HVR magnitude was characterised by the relative change in minute volume between normoxia and 30-s hyperoxia (VE_dH30). Time spent with an arterial haemoglobin oxygen saturation (SpO2) <90% during overnight monitoring (t90) was estimated. Results HVR data were available for 23 infants with chILD, 24 wheeze and 14 control infants. A significant decrease in minute volume under 30 s of hyperoxia was observed in all patients. HRT1 was shorter in chILD (5.6±1.2 s) and wheeze (5.9±1.5 s) groups than in the controls (12.6±5.5 s) (ANOVA p<0.001). VE_dH30 was increased in the chILD group (24.3±8.0%) compared with that in the controls (14.7±9.2%) (p=0.003). t90 was abnormal in the wheeze (8.0±5.0%) and chILD (32.7±25.8%) groups and higher in the chILD group than in the controls (p<0.001). HRT1 negatively correlated with t90 in all groups. Conclusion Significant differences in HVR timing and magnitude were noted in the chILD, wheeze and control groups. A relationship between nocturnal hypoxaemia and HRT1 was proposed. HVR characterisation may help identify patients with abnormal nocturnal SpO2.
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Affiliation(s)
- Václav Koucký
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University and University Hospital Motol, Prague, Czech Republic
| | - Pavlína Koucká
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University and University Hospital Motol, Prague, Czech Republic
| | - Miroslav Koucký
- Department of Mathematics, Faculty of Science, Humanities and Education, Technical University of Liberec, Liberec, Czech Republic
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2
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MacFarlane PM, Martin RJ, Di Fiore JM, Raffay TM, Tatsuoka C, Chen Z, Minich N, Quintas G, Sánchez-Illana Á, Kuligowski J, Piñeiro-Ramos JD, Vento M, Hibbs AM. Plasma serotonergic biomarkers are associated with hypoxemia events in preterm neonates. Pediatr Res 2023; 94:1436-1443. [PMID: 37188799 DOI: 10.1038/s41390-023-02620-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/15/2023] [Accepted: 04/07/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND Hypoxemia is a physiological manifestation of immature respiratory control in preterm neonates, which is likely impacted by neurotransmitter imbalances. We investigated relationships between plasma levels of the neurotransmitter serotonin (5-HT), metabolites of tryptophan (TRP), and parameters of hypoxemia in preterm neonates. METHODS TRP, 5-HT, 5-hydroxyindoleacetic acid (5-HIAA), and kynurenic acid (KA) were analyzed in platelet-poor plasma at ~1 week and ~1 month of life from a prospective cohort of 168 preterm neonates <31 weeks gestational age (GA). Frequency of intermittent hypoxemia (IH) events and percent time hypoxemic (<80%) were analyzed in a 6 h window after the blood draw. RESULTS At 1 week, infants with detectable plasma 5-HT had fewer IH events (OR (95% CI) = 0.52 (0.29, 0.31)) and less percent time <80% (OR (95% CI) = 0.54 (0.31, 0.95)) compared to infants with undetectable 5-HT. A similar relationship occurred at 1 month. At 1 week, infants with higher KA showed greater percent time <80% (OR (95% CI) = 1.90 (1.03, 3.50)). TRP, 5-HIAA or KA were not associated with IH frequency at either postnatal age. IH frequency and percent time <80% were positively associated with GA < 29 weeks. CONCLUSIONS Circulating neuromodulators 5-HT and KA might represent biomarkers of immature respiratory control contributing to hypoxemia in preterm neonates. IMPACT Hypoxemia events are frequent in preterm infants and are associated with poor outcomes. Mechanisms driving hypoxemia such as immature respiratory control may include central and peripheral imbalances in modulatory neurotransmitters. This study found associations between the plasma neuromodulators serotonin and kynurenic acid and parameters of hypoxemia in preterm neonates. Imbalances in plasma biomarkers affecting respiratory control may help identify neonates at risk of short- and long-term adverse outcomes.
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Affiliation(s)
- Peter Mathew MacFarlane
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA.
| | - Richard John Martin
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Juliann Marie Di Fiore
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Thomas Michael Raffay
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Curtis Tatsuoka
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Zhengyi Chen
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Nori Minich
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Guillermo Quintas
- Health and Biomedicine, Leitat Technological Center, Carrer de la Innovació, 2, 08225, Terrassa, Spain
- Analytical Unit, Health Research Institute La Fe, Avda Fernando Abril Martorell 106, 46026, Valencia, Spain
| | - Ángel Sánchez-Illana
- Neonatal Research Unit, Health Research Institute La Fe (IISLAFE), University & Polytechnic Hospita La Fe (HULAFE), Valencia, Spain
- Department of Analytical Chemistry, Chemistry Faculty, Universtitat de València, Burjassot, Spain
| | - Julia Kuligowski
- Neonatal Research Unit, Health Research Institute La Fe (IISLAFE), University & Polytechnic Hospita La Fe (HULAFE), Valencia, Spain
| | - José David Piñeiro-Ramos
- Neonatal Research Unit, Health Research Institute La Fe (IISLAFE), University & Polytechnic Hospita La Fe (HULAFE), Valencia, Spain
| | - Maximo Vento
- Neonatal Research Unit, Health Research Institute La Fe (IISLAFE), University & Polytechnic Hospita La Fe (HULAFE), Valencia, Spain
| | - Anna Maria Hibbs
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
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3
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Trachsel D, Erb TO, Hammer J, von Ungern‐Sternberg BS. Developmental respiratory physiology. Paediatr Anaesth 2022; 32:108-117. [PMID: 34877744 PMCID: PMC9135024 DOI: 10.1111/pan.14362] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/02/2021] [Accepted: 12/05/2021] [Indexed: 12/25/2022]
Abstract
Various developmental aspects of respiratory physiology put infants and young children at an increased risk of respiratory failure, which is associated with a higher rate of critical incidents during anesthesia. The immaturity of control of breathing in infants is reflected by prolonged central apneas and periodic breathing, and an increased risk of apneas after anesthesia. The physiology of the pediatric upper and lower airways is characterized by a higher flow resistance and airway collapsibility. The increased chest wall compliance and reduced gas exchange surface of the lungs reduce the pulmonary oxygen reserve vis-à-vis a higher metabolic oxygen demand, which causes more rapid oxygen desaturation when ventilation is compromised. This review describes the various developmental aspects of respiratory physiology and summarizes anesthetic implications.
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Affiliation(s)
- Daniel Trachsel
- Pediatric Intensive Care and PulmonologyUniversity Children’s Hospital of Basel UKBBBaselSwitzerland
| | - Thomas O. Erb
- Department AnesthesiologyUniversity Children’s Hospital of Basel UKBBBaselSwitzerland
| | - Jürg Hammer
- Pediatric Intensive Care and PulmonologyUniversity Children’s Hospital of Basel UKBBBaselSwitzerland
| | - Britta S. von Ungern‐Sternberg
- Department of Anaesthesia and Pain ManagementPerth Children’s HospitalPerthWAAustralia,Division of Emergency Medicine, Anaesthesia and Pain MedicineMedical SchoolThe University of Western AustraliaPerthWAAustralia,Perioperative Medicine TeamTelethon Kids InstitutePerthWAAustralia
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4
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Pergolizzi JV, Fort P, Miller TL, LeQuang JA, Raffa RB. The epidemiology of apnoea of prematurity. J Clin Pharm Ther 2022; 47:685-693. [PMID: 35018653 DOI: 10.1111/jcpt.13587] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 11/24/2021] [Accepted: 12/02/2021] [Indexed: 11/29/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Many premature infants less than 37 weeks gestational age (GA), and almost all infants less than 28 weeks GA, will experience apnoea of prematurity (AOP)-a cessation of respiration for 20 or more seconds (or less than 20 s if accompanied by other signs). Because the treatment options for AOP are so limited, we explore its epidemiology, with the ultimate hope of learning how to decrease its incidence. COMMENT Although AOP usually resolves with maturation of the respiratory system, many short- and long-term negative effects are correlated statistically with AOP (although direct causality has not been established). The primary risk factor for AOP is preterm birth, but delivery technique, genetics, socioeconomic status, racial disparities and other influences are suspected to be involved. Anaemia, asthma and gastric reflux have also been associated with preterm birth, but the relationship with AOP is unclear. The postulated associations and the strength of the evidence are briefly reviewed and discussed. WHAT IS NEW AND CONCLUSION Attempts to elucidate the epidemiology of apnoea of prematurity have been challenging. Studies of AOP are hampered in part by challenges in monitoring the condition, the interplay of multiple comorbidities in preterm neonates and lack of expert consensus definitions. However, since the primary risk factor is preterm birth, efforts to decrease the prevalence of preterm birth would have a positive secondary effect on the prevalence of AOP. Until then, better pharmacotherapeutic options are needed.
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Affiliation(s)
- Joseph V Pergolizzi
- NEMA Research Inc., Naples, Florida, USA.,Neumentum Inc., Summit, New Jersey, USA.,Enalare Therapeutics Inc., Princeton, New Jersey, USA
| | - Prem Fort
- Neonatology, Johns Hopkins All Children's Hospital, St. Petersburg, Florida, USA.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Thomas L Miller
- Enalare Therapeutics Inc., Princeton, New Jersey, USA.,Department of Pediatrics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | | | - Robert B Raffa
- Neumentum Inc., Summit, New Jersey, USA.,Enalare Therapeutics Inc., Princeton, New Jersey, USA.,College of Pharmacy (Adjunct), University of Arizona, Tucson, Arizona, USA.,Temple University School of Pharmacy (Prof. Emer.), Philadelphia, Pennsylvania, USA
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5
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Martin RJ, Mitchell LJ, MacFarlane PM. Apnea of prematurity and sudden infant death syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2022; 189:43-52. [PMID: 36031315 DOI: 10.1016/b978-0-323-91532-8.00010-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Apnea is a frequent occurrence in prematurity and its prevalence in the most severely preterm population is indicative of an immature respiratory neural control system. Preterm infants are also at increased risk of Sudden Infant Death Syndrome (SIDS), which has been associated with similar respiratory neural control dysfunction seen in prematurity. Generally, abnormalities in both central and peripheral mechanisms of respiratory control are thought to be key underlying features of abnormal respiratory system development. Numerous factors contribute to the etiology of apnea and respiratory control dysfunction including the environment (e.g., substance use/misuse), sex, genetics, a vulnerable neonate, and various underlying comorbidities. However, there are major gaps in our understanding of both normal and abnormal respiratory control system development, which highlights the need for continued research using novel and innovative methods.
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Affiliation(s)
- Richard J Martin
- Division of Neonatology, Department of Pediatrics, Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, United States.
| | - Lisa J Mitchell
- Division of Neonatology, Department of Pediatrics, Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, United States
| | - Peter M MacFarlane
- Division of Neonatology, Department of Pediatrics, Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, United States
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6
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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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7
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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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8
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Immature control of breathing and apnea of prematurity: the known and unknown. J Perinatol 2021; 41:2111-2123. [PMID: 33712716 PMCID: PMC7952819 DOI: 10.1038/s41372-021-01010-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 02/05/2021] [Accepted: 02/16/2021] [Indexed: 02/05/2023]
Abstract
This narrative review provides a broad perspective on immature control of breathing, which is universal in infants born premature. The degree of immaturity and severity of clinical symptoms are inversely correlated with gestational age. This immaturity presents as prolonged apneas with associated bradycardia or desaturation, or brief respiratory pauses, periodic breathing, and intermittent hypoxia. These manifestations are encompassed within the clinical diagnosis of apnea of prematurity, but there is no consensus on minimum criteria required for diagnosis. Common treatment strategies include caffeine and noninvasive respiratory support, but other therapies have also been advocated with varying effectiveness. There is considerable variability in when and how to initiate and discontinue treatment. There are significant knowledge gaps regarding effective strategies to quantify the severity of clinical manifestations of immature breathing, which prevent us from better understanding the long-term potential adverse outcomes, including neurodevelopment and sudden unexpected infant death.
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9
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Mitchell LJ, Mayer CA, Mayer A, Di Fiore JM, Shein SL, Raffay TM, MacFarlane PM. Caffeine prevents prostaglandin E 1-induced disturbances in respiratory control in neonatal rats: implications for infants with critical congenital heart disease. Am J Physiol Regul Integr Comp Physiol 2020; 319:R233-R242. [PMID: 32579854 DOI: 10.1152/ajpregu.00316.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Continuous infusion of prostaglandin E1 (PGE1) is used to maintain ductus arteriosus patency in infants with critical congenital heart disease, but it can also cause central apnea suggesting an effect on respiratory neural control. In this study, we investigated whether 1) PGE1 inhibits the various phases of the acute hypoxic ventilatory response (HVR; an index of respiratory control dysfunction) and increases apnea incidence in neonatal rats; and 2) whether these changes would be reversible with caffeine pretreatment. Whole body plethysmography was used to assess the HVR and apnea incidence in neonatal rats 2 h following a single bolus intraperitoneal injection of PGE1 with and without prior caffeine treatment. Untreated rats exhibited a biphasic HVR characterized by an initial increase in minute ventilation followed by a ventilatory decline of the late phase (~5th minute) of the HVR. PGE1 had a dose-dependent effect on the HVR. Contrary to our hypothesis, the lowest dose (1 µg/kg) of PGE1 prevented the ventilatory decline of the late phase of the HVR. However, PGE1 tended to increase postsigh apnea incidence and the coefficient of variability (CV) of breathing frequency, suggesting increased respiratory instability. PGE1 also decreased brainstem microglia mRNA and increased neuronal nitric oxide synthase (nNOS) and platelet-derived growth factor-β (PDGF-β) gene expression. Caffeine pretreatment prevented these effects of PGE1, and the adenosine A2A receptor inhibitor MSX-3 had similar preventative effects. Prostaglandin appears to have deleterious effects on brainstem respiratory control regions, possibly involving a microglial-dependent mechanism. The compensatory effects of caffeine or MSX-3 treatment raises the question of whether prostaglandin may also operate on an adenosine-dependent pathway.
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Affiliation(s)
- L J Mitchell
- Department of Pediatrics, Division of Neonatology, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio
| | - C A Mayer
- Department of Pediatrics, Division of Neonatology, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio
| | - A Mayer
- Department of Pediatrics, Division of Neonatology, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio
| | - J M Di Fiore
- Department of Pediatrics, Division of Neonatology, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio
| | - S L Shein
- Department of Pediatrics, Division of Pediatric Critical Care, Rainbow Babies and Children's Hospital, Cleveland, Ohio
| | - T M Raffay
- Department of Pediatrics, Division of Neonatology, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio
| | - P M MacFarlane
- Department of Pediatrics, Division of Neonatology, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio
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10
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Ventilatory and carotid body responses to acute hypoxia in rats exposed to chronic hypoxia during the first and second postnatal weeks. Respir Physiol Neurobiol 2020; 275:103400. [PMID: 32006667 DOI: 10.1016/j.resp.2020.103400] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/20/2019] [Accepted: 01/27/2020] [Indexed: 01/24/2023]
Abstract
Chronic hypoxia (CH) during postnatal development causes a blunted hypoxic ventilatory response (HVR) in neonatal mammals. The magnitude of the HVR generally increases with age, so CH could blunt the HVR by delaying this process. Accordingly, we predicted that CH would have different effects on the respiratory control of neonatal rats if initiated at birth versus initiated later in postnatal development (i.e., after the HVR has had time to mature). Rats had blunted ventilatory and carotid body responses to hypoxia whether CH (12 % O2) occurred for the first postnatal week (P0 to P7) or second postnatal week (P7 to P14). However, if initiated at P0, CH also caused the HVR to retain the "biphasic" shape characteristic of newborn mammals; CH during the second postnatal week did not result in a biphasic HVR. CH from birth delayed the transition from a biphasic HVR to a sustained HVR until at least P9-11, but the HVR attained a sustained (albeit blunted) phenotype by P13-15. Since delayed maturation of the HVR did not completely explain the blunted HVR, we tested the alternative hypothesis that the blunted HVR was caused by an inflammatory response to CH. Daily administration of the anti-inflammatory drug ibuprofen (4 mg kg-1, i.p.) did not alter the effects of CH on the HVR. Collectively, these data suggest that CH blunts the HVR in neonatal rats by impairing carotid body responses to hypoxia and by delaying (but not preventing) postnatal maturation of the biphasic HVR. The mechanisms underlying this plasticity require further investigation.
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11
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Mitchell L, MacFarlane PM. Mechanistic actions of oxygen and methylxanthines on respiratory neural control and for the treatment of neonatal apnea. Respir Physiol Neurobiol 2020; 273:103318. [PMID: 31626973 PMCID: PMC6986994 DOI: 10.1016/j.resp.2019.103318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 12/14/2022]
Abstract
Apnea remains one of the most concerning and prevalent respiratory disorders spanning all ages from infants (particularly those born preterm) to adults. Although the pathophysiological consequences of apnea are fairly well described, the neural mechanisms underlying the etiology of the different types of apnea (central, obstructive, and mixed) still remain incompletely understood. From a developmental perspective, however, research into the respiratory neural control system of immature animals has shed light on both central and peripheral neural pathways underlying apnea of prematurity (AOP), a highly prevalent respiratory disorder of preterm infants. Animal studies have also been fundamental in furthering our understanding of how clinical interventions (e.g. pharmacological and mechanical) exert their beneficial effects in the clinical treatment of apnea. Although current clinical interventions such as supplemental O2 and positive pressure respiratory support are critically important for the infant in respiratory distress, they are not fully effective and can also come with unfortunate, unintended (and long-term) side-effects. In this review, we have chosen AOP as one of the most common clinical scenarios involving apnea to highlight the mechanistic basis behind how some of the interventions could be both beneficial and also deleterious to the respiratory neural control system. We have included a section on infants with critical congenital heart diseases (CCHD), in whom apnea can be a clinical concern due to treatment with prostaglandin, and who may benefit from some of the treatments used for AOP.
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Affiliation(s)
- Lisa Mitchell
- Department of Pediatrics, Case Western Reserve University, Rainbow Babies & Children's Hospital, Cleveland, OH 44106, USA
| | - Peter M MacFarlane
- Department of Pediatrics, Case Western Reserve University, Rainbow Babies & Children's Hospital, Cleveland, OH 44106, USA.
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12
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Beyeler SA, Hodges MR, Huxtable AG. Impact of inflammation on developing respiratory control networks: rhythm generation, chemoreception and plasticity. Respir Physiol Neurobiol 2020; 274:103357. [PMID: 31899353 DOI: 10.1016/j.resp.2019.103357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/17/2019] [Accepted: 12/02/2019] [Indexed: 10/25/2022]
Abstract
The respiratory control network in the central nervous system undergoes critical developmental events early in life to ensure adequate breathing at birth. There are at least three "critical windows" in development of respiratory control networks: 1) in utero, 2) newborn (postnatal day 0-4 in rodents), and 3) neonatal (P10-13 in rodents, 2-4 months in humans). During these critical windows, developmental processes required for normal maturation of the respiratory control network occur, thereby increasing vulnerability of the network to insults, such as inflammation. Early life inflammation (induced by LPS, chronic intermittent hypoxia, sustained hypoxia, or neonatal maternal separation) acutely impairs respiratory rhythm generation, chemoreception and increases neonatal risk of mortality. These early life impairments are also greater in young males, suggesting sex-specific impairments in respiratory control. Further, neonatal inflammation has a lasting impact on respiratory control by impairing adult respiratory plasticity. This review focuses on how inflammation alters respiratory rhythm generation, chemoreception and plasticity during each of the three critical windows. We also highlight the need for additional mechanistic studies and increased investigation into how glia (such as microglia and astrocytes) play a role in impaired respiratory control after inflammation. Understanding how inflammation during critical windows of development disrupt respiratory control networks is essential for developing better treatments for vulnerable neonates and preventing adult ventilatory control disorders.
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Affiliation(s)
- Sarah A Beyeler
- Department of Human Physiology, University of Oregon, Eugene, OR, 97403, United States
| | - Matthew R Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Adrianne G Huxtable
- Department of Human Physiology, University of Oregon, Eugene, OR, 97403, United States.
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13
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Seppä‐Moilanen M, Andersson S, Rantakari K, Mikkola K, Kirjavainen T. Caffeine and supplemental oxygen effectively suppress periodic breathing with only minor effects during long episodes of apnoea in preterm infants. Acta Paediatr 2019; 108:443-451. [PMID: 30118174 DOI: 10.1111/apa.14541] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/13/2018] [Indexed: 12/29/2022]
Abstract
AIM We investigated the characteristics and effects of sleep stage, supplemental oxygen and caffeine on periodic breathing (PB) and apnoea of prematurity (AOP) in preterm infants. METHODS This 2013-2015 study recruited 21 preterm infants on neonatal wards in the Helsinki and Uusimaa Hospital District, Finland, at a median corrected gestational age of 35.7 weeks and performed polysomnography at baseline, during supplemental oxygen and during caffeine treatment. RESULTS All infants demonstrated PB, during a median of 11% of sleep time and 85% of PB occurred during non-rapid eye movement sleep (NREM). Apnoea episodes were brief during PB, but 66% were associated with oxygen desaturation. Supplemental oxygen substantially reduced PB time by 99% and caffeine by 91%. Oxygen desaturation decreased from 38 per hour at baseline to 8.5 with oxygen and 24 with caffeine (all p < 0.001). AOPs decreased from 1.4 per hour at baseline to 0.4 with oxygen (p = 0.03) and 0.3 with caffeine (p = 0.07). Most (84%) apnoea episodes over 15 seconds were mixed episodes during REM sleep. CONCLUSION PB occurred predominantly during NREM sleep, caused intermittent hypoxia, and was suppressed by supplemental oxygen and caffeine. In contrast, long apnoea episodes representing AOP were only modestly decreased.
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Affiliation(s)
- Maija Seppä‐Moilanen
- Children‘s Hospital Paediatric Research Center University of Helsinki Helsinki University Hospital Helsinki Finland
| | - Sture Andersson
- Children‘s Hospital Paediatric Research Center University of Helsinki Helsinki University Hospital Helsinki Finland
| | - Krista Rantakari
- Children‘s Hospital Paediatric Research Center University of Helsinki Helsinki University Hospital Helsinki Finland
| | - Kaija Mikkola
- Children‘s Hospital Paediatric Research Center University of Helsinki Helsinki University Hospital Helsinki Finland
| | - Turkka Kirjavainen
- Children‘s Hospital Paediatric Research Center University of Helsinki Helsinki University Hospital Helsinki Finland
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Hasenstab KA, Nawaz S, Lang IM, Shaker R, Jadcherla SR. Pharyngoesophageal and cardiorespiratory interactions: potential implications for premature infants at risk of clinically significant cardiorespiratory events. Am J Physiol Gastrointest Liver Physiol 2019; 316:G304-G312. [PMID: 30543445 PMCID: PMC6397335 DOI: 10.1152/ajpgi.00303.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The aims of this study were to 1) examine pharyngoesophageal and cardiorespiratory responses to provoking pharyngeal stimuli, and 2) to determine potential contributory factors impacting heart rate (HR) changes to provide insight into cardiorespiratory events occurring in preterm infants. Forty-eight neonates (19 females and 29 males, born at 27.7 ± 0.5 wk; mean ± SE) pending discharge on full oral feeds were studied at 38.7 ± 0.2 wk postmenstrual age using concurrent pharyngoesophageal manometry, electrocardiography, respiratory inductance plethysmography, and nasal airflow thermistor. Pharyngoesophageal and cardiorespiratory responses (prevalence, latency, and duration) were quantified upon abrupt pharyngeal water stimuli (0.1, 0.3, and 0.5 ml in triplicate). Mixed linear models and generalized estimating equations were used for comparisons between HR changes. Contributory factors included stimulus characteristics and subject characteristics. Of 338 pharyngeal stimuli administered, HR increased in 23 (7%), decreased in 108 (32%), and remained stable in 207 (61%) neonates. HR decrease resulted in repetitive swallowing, increased respiratory-rhythm disturbance, and decreased esophageal propagation rates (all, P < 0.05). HR responses were related to stimulus volume, stimulus flow rate, and extreme prematurity (all, P < 0.05). In preterm infants, HR remains stable in a majority of pharyngeal provocations. HR decrease, due to pharyngeal stimulation, is related to aberrant pharyngoesophageal motility and respiratory dysregulation and is magnified by prematurity. We infer that the observed aberrant responses across digestive, respiratory, and cardiovascular systems are related to maladaptive maturation of the parasympathetic nervous system. These aberrant responses may provide diagnostic clues for risk stratification of infants with troublesome cardiorespiratory events and swallowing difficulty. NEW & NOTEWORTHY Cardiorespiratory rhythms concurrent with pharyngeal, upper esophageal sphincter, and esophageal body responses were examined upon pharyngeal provocation in preterm-born infants who were studied at full-term maturation. Decreased heart rate (HR) was associated with extreme preterm birth and stimulus flow/volume. With HR decrease responses, aerodigestive reflex abnormalities were present, characterized by prolonged respiratory rhythm disturbance, repetitive multiple swallowing, and poor esophageal propagation. Promoting esophageal peristalsis may be a potential therapeutic target.
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Affiliation(s)
- Kathryn A. Hasenstab
- 1Innovative Neonatal and Infant Feeding Disorders Research Program, Center for Perinatal Research, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio
| | - Saira Nawaz
- 1Innovative Neonatal and Infant Feeding Disorders Research Program, Center for Perinatal Research, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio
| | - Ivan M. Lang
- 2Medical College of Wisconsin Dysphagia Institute, Division of Gastroenterology and Hepatology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Reza Shaker
- 2Medical College of Wisconsin Dysphagia Institute, Division of Gastroenterology and Hepatology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Sudarshan R. Jadcherla
- 1Innovative Neonatal and Infant Feeding Disorders Research Program, Center for Perinatal Research, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio,3Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio,4Division of Neonatology, Pediatric Gastroenterology and Nutrition, Nationwide Children’s Hospital, Columbus, Ohio
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Bates ML, Welch BT, Randall JT, Petersen-Jones HG, Limberg JK. Carotid body size measured by computed tomographic angiography in individuals born prematurely. Respir Physiol Neurobiol 2018; 258:47-52. [PMID: 29803761 DOI: 10.1016/j.resp.2018.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 05/07/2018] [Accepted: 05/24/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE We tested the hypothesis that the carotid bodies would be smaller in individuals born prematurely or exposed to perinatal oxygen therapy when compared individuals born full term that did not receive oxygen therapy. METHODS A retrospective chart review was conducted on patients who underwent head/neck computed tomography angiography (CTA) at the Mayo Clinic between 10 and 40 years of age (n = 2503). Patients were identified as premature ( < 38 weeks) or receiving perinatal oxygen therapy by physician completion or billing codes (n = 16 premature and n = 7 receiving oxygen). Widest axial measurements of the carotid body images captured during the CTA were performed. RESULTS Carotid body visualization was possible in 43% of patients and 52% of age, sex, and body mass index (BMI)-matched controls but only 17% of juvenile preterm subjects (p = .07). Of the carotid bodies that could be visualized, widest axial measurements of the carotid bodies in individuals born prematurely (n = 7, 34 ± 4 weeks gestation, birth weight: 2460 ± 454 g; average size: 2.5 ± 0.2 cm) or individuals exposed to perinatal oxygen therapy (n = 3, 38 ± 2 weeks gestation, Average size: 2.2 ± 0.1 cm) were not different when compared to controls (2.3 ± 0.2 cm and 2.3 ± 0.2 cm, respectively, p > 0.05). CONCLUSIONS Carotid body size, as measured using CTA, is not smaller in adults born prematurely or exposed to perinatal oxygen therapy when compared to sex, age, and BMI-matched controls. However, carotid body visualization was lower in juvenile premature patients. The decreased ability to visualize the carotid bodies in these individuals may be a result of their prematurity.
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Affiliation(s)
- Melissa L Bates
- Department of Health and Human Physiology, USA; Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
| | - Brian T Welch
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Jess T Randall
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | | | - Jacqueline K Limberg
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, USA.
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Ortiz LE, McGrath-Morrow SA, Sterni LM, Collaco JM. Sleep disordered breathing in bronchopulmonary dysplasia. Pediatr Pulmonol 2017; 52:1583-1591. [PMID: 29064170 PMCID: PMC5693767 DOI: 10.1002/ppul.23769] [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] [Received: 03/28/2017] [Accepted: 06/20/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND There are limited data on the effect of bronchopulmonary dysplasia (BPD) on sleep disordered breathing (SDB). We hypothesized that both the severity of prematurity and BPD would increase the likelihood of SDB in early childhood. Our secondary aim was to evaluate the association of demographic factors on the development of SDB. METHODS This is a retrospective study of patient factors and overnight polysomnogram (PSG) data of children enrolled in our BPD registry between 2008 and 2015. Association between PSG results and studied variables was assessed using multiple linear regression analysis. RESULTS One-hundred-forty children underwent at least one sleep study on room air. The mean respiratory disturbance index (RDI) was elevated at 9.9 events/hr (SD: 10.1). The mean obstructive apnea-hypopnea index (OAHI) was 6.5 (9.1) events/hr and the mean central event rate of 3.0 (3.7) events/hr. RDI had decreased by 22% or 1.5 events/hour (95%CI: 0.6, 1.9) with each year of age (P = 0.005). Subjects with more severe respiratory disease had 38% more central events (P = 0.02). Infants exposed to secondhand smoke had 2.4% lower (P = 0.04) oxygen saturation nadirs and a pattern for more desaturation events. Non-white subjects were found to have 33% higher OAHI (P = 0.05), while white subjects had a 61% higher rate of central events (P < 0.001). CONCLUSIONS RDI was elevated in a selected BPD population compared to norms for non-preterm children. BPD severity, smoke exposure, and race may augment the severity of SDB. RDI improved with age but was still elevated by age 4, suggesting that this population is at risk for the sequelae of SDB.
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Affiliation(s)
- Luis E Ortiz
- Johns Hopkins Medical Institutions, Baltimore, Maryland
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17
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Cardiorespiratory events in preterm infants: etiology and monitoring technologies. J Perinatol 2016; 36:165-71. [PMID: 26583939 DOI: 10.1038/jp.2015.164] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 10/05/2015] [Indexed: 12/13/2022]
Abstract
Every year, an estimated 15 million infants are born prematurely (<37 weeks gestation) with premature birth rates ranging from 5 to 18% across 184 countries. Although there are a multitude of reasons for this high rate of preterm birth, once birth occurs, a major challenge of infant care includes the stabilization of respiration and oxygenation. Clinical care of this vulnerable infant population continues to improve, yet there are major areas that have yet to be resolved including the identification of optimal respiratory support modalities and oxygen saturation targets, and reduction of associated short- and long-term morbidities. As intermittent hypoxemia is a consequence of immature respiratory control and resultant apnea superimposed upon an immature lung, improvements in clinical care must include a thorough knowledge of premature lung development and pathophysiology that is unique to premature birth. In Part 1 of a two-part review, we summarize early lung development and diagnostic methods for cardiorespiratory monitoring.
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Bairam A, Uppari N, Mubayed S, Joseph V. An Overview on the Respiratory Stimulant Effects of Caffeine and Progesterone on Response to Hypoxia and Apnea Frequency in Developing Rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 860:211-20. [DOI: 10.1007/978-3-319-18440-1_23] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Mayer CA, Wilson CG, MacFarlane PM. Changes in carotid body and nTS neuronal excitability following neonatal sustained and chronic intermittent hypoxia exposure. Respir Physiol Neurobiol 2014; 205:28-36. [PMID: 25266393 DOI: 10.1016/j.resp.2014.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 09/21/2014] [Accepted: 09/22/2014] [Indexed: 02/07/2023]
Abstract
We investigated whether pre-treatment with neonatal sustained hypoxia (SH) prior to chronic intermittent hypoxia (SH+CIH) would modify in vitro carotid body (CB) chemoreceptor activity and the excitability of neurons in the caudal nucleus of the solitary tract (nTS). Sustained hypoxia followed by CIH exposure simulates an oxygen paradigm experienced by extremely premature infants who developed persistent apnea. Rat pups were treated with 5 days of SH (11% O2) from postnatal age 1 (P1) followed by 10 days of subsequent chronic intermittent hypoxia (CIH, 5% O2/5 min, 8 h/day, between P6 and P15) as described previously (Mayer et al., Respir. Physiol. Neurobiol. 187(2): 167-75, 2013). At the end of SH+CIH exposure (P16), basal firing frequency was enhanced, and the hypoxic sensory response of single unit CB chemoafferents was attenuated. Further, basal firing frequency and the amplitude of evoked excitatory post-synaptic currents (ESPC's) of nTS neurons was augmented compared to age-matched rats raised in normoxia. These effects were unique to SH+CIH exposure as neither SH or CIH alone elicited any comparable effect on chemoafferent activity or nTS function. These data indicated that pre-treatment with neonatal SH prior to CIH exposure uniquely modified mechanisms of peripheral (CB) and central (nTS) neural function in a way that would be expected to disturb the ventilatory response to acute hypoxia.
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Affiliation(s)
- C A Mayer
- Department of Pediatrics, Case Western Reserve University, Rainbow Babies & Children's Hospital, Cleveland, OH 44106, USA
| | - C G Wilson
- Center for Perinatal Biology, Loma Linda University, Loma Linda, CA 92350, USA
| | - P M MacFarlane
- Department of Pediatrics, Case Western Reserve University, Rainbow Babies & Children's Hospital, Cleveland, OH 44106, USA.
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Mayer CA, Di Fiore JM, Martin RJ, Macfarlane PM. Vulnerability of neonatal respiratory neural control to sustained hypoxia during a uniquely sensitive window of development. J Appl Physiol (1985) 2013; 116:514-21. [PMID: 24371020 DOI: 10.1152/japplphysiol.00976.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The first postnatal weeks represent a period of development in the rat during which the respiratory neural control system may be vulnerable to aberrant environmental stressors. In the present study, we investigated whether sustained hypoxia (SH; 11% O2) exposure starting at different postnatal ages differentially modifies the acute hypoxic (HVR) and hypercapnic ventilatory response (HCVR). Three different groups of rat pups were exposed to 5 days of SH, starting at either postnatal age 1 (SH1-5), 11 (SH11-15), or 21 (SH21-25) days. Whole body plethysmography was used to assess the HVR and HCVR the day after SH exposure ended. The primary results indicated that 1) the HVR and HCVR of SH11-15 rats were absent or attenuated (respectively) compared with age-matched rats raised in normoxia; 2) there was a profoundly high (∼84% of pups) incidence of unexplained mortality in the SH11-15 rats; and 3) these phenomena were unique to the SH11-15 group with no comparable effect of the SH exposure on the HVR, HCVR, or mortality in the younger (SH1-5) or older (SH21-25) rats. These results share several commonalities with the risk factors thought to underlie the etiology of sudden infant death syndrome, including 1) a vulnerable neonate; 2) a critical period of development; and 3) an environmental stressor.
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Affiliation(s)
- C A Mayer
- Department of Pediatrics, Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, Ohio
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21
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Bates ML, Pillers DAM, Palta M, Farrell ET, Eldridge MW. Ventilatory control in infants, children, and adults with bronchopulmonary dysplasia. Respir Physiol Neurobiol 2013; 189:329-37. [PMID: 23886637 DOI: 10.1016/j.resp.2013.07.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 07/16/2013] [Accepted: 07/16/2013] [Indexed: 12/17/2022]
Abstract
Bronchopulmonary dysplasia (BPD), or chronic lung disease of prematurity, occurs in ~30% of preterm infants (15,000 per year) and is associated with a clinical history of mechanical ventilation and/or high inspired oxygen at birth. Here, we describe changes in ventilatory control that exist in patients with BPD, including alterations in chemoreceptor function, respiratory muscle function, and suprapontine control. Because dysfunction in ventilatory control frequently revealed when O2 supply and CO2 elimination are challenged, we provide this information in the context of four important metabolic stressors: stresses: exercise, sleep, hypoxia, and lung disease, with a primary focus on studies of human infants, children, and adults. As a secondary goal, we also identify three key areas of future research and describe the benefits and challenges of longitudinal human studies using well-defined patient cohorts.
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Affiliation(s)
- Melissa L Bates
- Department of Pediatrics, Division of Critical Care, University of Wisconsin, Madison, WI, USA; John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin, Madison, WI, USA.
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Mayer CA, Ao J, Di Fiore JM, Martin RJ, MacFarlane PM. Impaired hypoxic ventilatory response following neonatal sustained and subsequent chronic intermittent hypoxia in rats. Respir Physiol Neurobiol 2013; 187:167-75. [PMID: 23562917 DOI: 10.1016/j.resp.2013.03.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 03/20/2013] [Accepted: 03/21/2013] [Indexed: 11/15/2022]
Abstract
Neonatal chronic intermittent hypoxia (CIH) enhances the ventilatory sensitivity to acute hypoxia (acute hypoxic ventilatory response, HVR), whereas sustained hypoxia (SH) can have the opposite effect. Therefore, we investigated whether neonatal rats pre-treated with SH prior to CIH exhibit a modified HVR. Rat pups were exposed to CIH (5% O2/5min, 8h/day) between 6 and 15 days of postnatal age (P6-15) after pre-treatment with either normoxia or SH (11% O2; P1-5). Using whole-body plethysmography, the acute (5min, 10% O2) HVR at P16 (1 day post-CIH) was unchanged following CIH (67.9±6.7% above baseline) and also SH (58.8±10.5%) compared to age-matched normoxic rats (54.7±6.3%). In contrast, the HVR was attenuated (16.5±6.0%) in CIH exposed rats pre-treated with SH. These data suggest that while neonatal SH and CIH alone have little effect on the magnitude of the acute HVR, their combined effects impose a synergistic disturbance to postnatal development of the HVR. These data could provide important insight into the consequences of not maintaining adequate levels of oxygen saturation during the early neonatal period, especially in vulnerable preterm infants susceptible to frequent bouts of hypoxemic events (CIH) that are commonly associated with apnea of prematurity.
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Affiliation(s)
- C A Mayer
- Department of Pediatrics, Case Western Reserve University, Rainbow Babies & Children's Hospital, Cleveland, OH 44106, USA
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Chintamaneni K, Bruder ED, Raff H. Effects of age on ACTH, corticosterone, glucose, insulin, and mRNA levels during intermittent hypoxia in the neonatal rat. Am J Physiol Regul Integr Comp Physiol 2013; 304:R782-9. [PMID: 23485866 DOI: 10.1152/ajpregu.00073.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Apnea, the temporary cessation of respiratory airflow, is a common cause of intermittent hypoxia (IH) in premature infants. We hypothesized that IH elicits a stress response and alters glucose homeostasis in the neonatal rat. Rat pups were studied on postnatal day (PD) 2, 8, 10, 12, and 14. Pups were exposed to normoxia (control) or six cycles consisting of 30-s exposures to hypoxia (FiO2 = 3%) over a 60-min period. Blood samples were obtained at baseline, after the third cycle (~30 min), and after the sixth cycle (~60 min). Tissue samples were collected following the sixth cycle. Plasma ACTH, corticosterone, glucose, and insulin were analyzed at all ages. Hypothalamic, pituitary, and adrenal mRNA expression was evaluated by quantitative PCR in PD2, PD8, and PD12 pups. Exposure to IH elicited significant increases in plasma ACTH and corticosterone at all ages studied. The largest increase in corticosterone occurred in PD2 pups, despite only a very small increase in plasma ACTH. This ACTH-independent increase in corticosterone in PD2 pups was associated with increases in adrenal Ldlr and Star mRNA expression. Additionally, IH caused hyperglycemia and hyperinsulinemia at all ages. We conclude that IH elicits a significant pituitary-adrenal response and significantly alters glucose homeostasis. Furthermore, the quantitative and qualitative characteristics of these responses depend on developmental age.
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Affiliation(s)
- Kathan Chintamaneni
- Endocrine Research Laboratory, Aurora St. Luke's Medical Center, Aurora Research Institute, Milwaukee, WI 53215, USA
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Carroll JL, Donnelly DF, Bairam A. Foreword. Development of the carotid body. Respir Physiol Neurobiol 2013; 185:1-2. [PMID: 23078973 DOI: 10.1016/j.resp.2012.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 10/09/2012] [Indexed: 11/29/2022]
Affiliation(s)
- John L Carroll
- Division of Pediatric Pulmonary Medicine, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72202, USA.
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