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da Silva RB, Neves VR, Montarroyos UR, Silveira MS, Sobral Filho DC. Heart rate variability as a predictor of mechanical ventilation weaning outcomes. Heart Lung 2023; 59:33-36. [PMID: 36706686 DOI: 10.1016/j.hrtlng.2023.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 01/04/2023] [Accepted: 01/15/2023] [Indexed: 01/27/2023]
Abstract
BACKGROUND Delays in the mechanical ventilation (MV) weaning process increase mortality. The spontaneous breathing test is the gold standard to assess weaning and extubation success, although it has approximately 85% accuracy. Studies have demonstrated a correlation between decreased heart rate variability (HRV) and weaning failure. OBJECTIVES To assess the usefulness of HRV as a predictor of MV weaning outcomes. METHODS Cross-sectional analytical study in adults of both sexes on MV in intensive care unit (ICU) stay. Patients were divided into weaning success and failure groups. Clinical data were collected, and HRV records were obtained with a heart rate monitor. RESULTS The study included 68 individuals - 91.1% in the weaning success group and 8.9% in the failure group. All HRV indices analyzed in both groups were lower than the reference values. No statistical difference was found in the mean RR interval (RRi), the standard deviation of the NN interval (SDNN), and the square root of the mean squared differences of successive NN intervals (RMSSD) between the groups. The weaning failure group had a significant increase in LF (41 vs. 69.4) and LF/HF ratio (0.685 vs. 2.6) and a significant decrease in HF (58.85 vs. 30.2). CONCLUSIONS HRV measure with spectral analysis can be a good predictor of MV weaning failure. Integrating this assessment tool in ICU to predict weaning outcomes could provide more precise prognoses and more adequate assistance quality.
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Affiliation(s)
- Renata Baltar da Silva
- Postgraduation Program in Health Sciences (PPGCS), University of Pernambuco (UPE), Recife, PE, Brazil; Clinics Hospital of the Federal University of Pernambuco (HC-UFPE) - Brazilian Hospital Services Company (EBSERH), Recife, PE, Brazil; Agamenon Magalhães Hospital (HAM), UPE, Recife, PE, Brazil.
| | - Victor Ribeiro Neves
- Postgraduation Program in Functional Rehabilitation and Performance (PPGRDF), UPE, Petrolina, PE, Brazil.
| | - Ulisses Ramos Montarroyos
- Postgraduation Program in Health Sciences (PPGCS), University of Pernambuco (UPE), Recife, PE, Brazil.
| | - Matheus Sobral Silveira
- Postgraduation Program in Functional Rehabilitation and Performance (PPGRDF), UPE, Petrolina, PE, Brazil.
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Naar J, Mlcek M, Kruger A, Vondrakova D, Janotka M, Popkova M, Kittnar O, Neuzil P, Ostadal P. Acute Severe Heart Failure Reduces Heart Rate Variability: An Experimental Study in a Porcine Model. Int J Mol Sci 2022; 24:ijms24010493. [PMID: 36613937 PMCID: PMC9820097 DOI: 10.3390/ijms24010493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/22/2022] [Accepted: 12/25/2022] [Indexed: 12/29/2022] Open
Abstract
There are substantial differences in autonomic nervous system activation among heart (cardiac) failure (CF) patients. The effect of acute CF on autonomic function has not been well explored. The aim of our study was to assess the effect of experimental acute CF on heart rate variability (HRV). Twenty-four female pigs with a mean body weight of 45 kg were used. Acute severe CF was induced by global myocardial hypoxia. In each subject, two 5-min electrocardiogram segments were analyzed and compared: before the induction of myocardial hypoxia and >60 min after the development of severe CF. HRV was assessed by time-domain, frequency-domain and nonlinear analytic methods. The induction of acute CF led to a significant decrease in cardiac output, left ventricular ejection fraction and an increase in heart rate. The development of acute CF was associated with a significant reduction in the standard deviation of intervals between normal beats (50.8 [20.5−88.1] ms versus 5.9 [2.4−11.7] ms, p < 0.001). Uniform HRV reduction was also observed in other time-domain and major nonlinear analytic methods. Similarly, frequency-domain HRV parameters were significantly changed. Acute severe CF induced by global myocardial hypoxia is associated with a significant reduction in HRV.
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Affiliation(s)
- Jan Naar
- Department of Cardiology, Na Homolce Hospital, 150 30 Prague, Czech Republic
- Correspondence: ; Tel.: +420-257-272-208; Fax: +420-257-272-342
| | - Mikulas Mlcek
- Department of Physiology, First Faculty of Medicine, Charles University, 128 00 Prague, Czech Republic
| | - Andreas Kruger
- Department of Cardiology, Na Homolce Hospital, 150 30 Prague, Czech Republic
| | - Dagmar Vondrakova
- Department of Cardiology, Na Homolce Hospital, 150 30 Prague, Czech Republic
| | - Marek Janotka
- Department of Cardiology, Na Homolce Hospital, 150 30 Prague, Czech Republic
| | - Michaela Popkova
- Department of Physiology, First Faculty of Medicine, Charles University, 128 00 Prague, Czech Republic
| | - Otomar Kittnar
- Department of Physiology, First Faculty of Medicine, Charles University, 128 00 Prague, Czech Republic
| | - Petr Neuzil
- Department of Cardiology, Na Homolce Hospital, 150 30 Prague, Czech Republic
| | - Petr Ostadal
- Department of Cardiology, Na Homolce Hospital, 150 30 Prague, Czech Republic
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Crescimanno G, Greco F, Bertini M, Marrone O. Cardiovascular autonomic control during application of different modes of noninvasive ventilation in patients affected by amyotrophic lateral sclerosis. Heart Lung 2022; 56:161-166. [PMID: 35930914 DOI: 10.1016/j.hrtlng.2022.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Cardiovascular events commonly cause death in amyotrophic lateral sclerosis (ALS) even in patients treated by noninvasive ventilation (NIV). OBJECTIVES to evaluate autonomic function with the assessment of heart rate variability (HRV) in ALS patients treated by assist pressure control ventilation (APCV) and assist control ventilation (ACV) during sleep. METHODS Consecutive ALS patients underwent one polysomnography during APCV and one during ACV. HRV was analyzed both in the total sleep period (from first stage N1 to last awakening) and in a 5-minute period of stable stage N2. Time domain, frequency domain and nonlinear indexes of HRV were measured. RESULTS Nineteen patients (age 62.0 ± 8.7, 9F/10 M) were studied. The analysis did not reveal differences in blood gasses between NIV modalities, but a longer expiratory time (3.01±0.6 vs 2.8 ± 0.6 s, respectively APCV vs ACV, p = 0.001) and a lower arousal index (17.5 ± 9.1 vs 23.1 ± 13.9, p = 0.02) during APCV. HRV was indicative of higher vagal activity during APCV, especially in the 5-minute periods. In the total sleep periods, the HRV time domain indexes reflecting parasympathetic activity were positively correlated with the expiratory time and negatively with the inspiratory/expiratory time ratio. Low frequencies were positively, and high frequencies negatively, correlated with inspiratory time. HRV and sleep structure parameters were not correlated, except very low frequencies that were correlated to the arousal index. CONCLUSIONS Respiratory influences on autonomic control can be preserved in ALS. The slower breathing pattern during APCV may help to maintain a higher vagal activity. Through this mechanism, in the long-term APCV could more beneficial to ALS patients than ACV.
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Affiliation(s)
- Grazia Crescimanno
- National Research Council, Institute of Biomedical research and Innovation (IRIB-CNR); Regional Centre for Respiratory Complications of Rare Neuromuscular Diseases, Villa Sofia-Cervello Hospital Palermo.
| | - Francesca Greco
- Italian Union against Muscular Dystrophy, section of Palermo, Italy
| | - Manuela Bertini
- Regional Centre for Respiratory Complications of Rare Neuromuscular Diseases, Villa Sofia-Cervello Hospital Palermo
| | - Oreste Marrone
- National Research Council, Institute of Biomedical research and Innovation (IRIB-CNR)
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Influence of Spontaneous and Mechanical Ventilation on Frequency-Based Measures of Heart Rate Variability. Crit Care Res Pract 2022; 2021:8709262. [PMID: 34987867 PMCID: PMC8720601 DOI: 10.1155/2021/8709262] [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: 10/31/2021] [Accepted: 12/07/2021] [Indexed: 11/17/2022] Open
Abstract
Frequency-based measures of heart rate variability have been shown to be a useful physiological marker in both clinical and research settings providing insight into the functioning of the autonomic nervous system. Ongoing interactions between the autonomic nervous system control of the heart and lung occurs during each ventilation cycle because of their anatomical position within the closed thoracic cavity. Mechanical ventilation and subsequent removal change the normal ventilator mechanics producing alterations in the tidal volume, intrathoracic pressure, and oxygen delivery. A noninvasive method called heart rate variability (HRV) can be used to evaluate this interaction during ventilation and can be quantified by applying frequency-based measures of the variability between heartbeats. Although HRV is a reliable method to measure alteration of the autonomic nervous system (ANS) function and cardiopulmonary interaction, there have been limited reports concerning the changes in the frequency-based measure of HRV during both spontaneous and mechanical ventilation. The purpose of this methodological study is therefore to describe the physiological influence of both spontaneous and mechanical ventilation on frequency-based measures of HRV.
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Silva AMVD, Nard ATD, Righi GDA, Nascimento JR, Lima RM, Signori LU. Bilevel positive airway pressure improves the autonomic balance in the postoperative period following cardiac surgery: a randomized trial. FISIOTERAPIA E PESQUISA 2022. [DOI: 10.1590/1809-2950/19023129012022en] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT The use of bilevel positive airway pressure (BiPAP) has repercussions on cardiorespiratory outcomes. However, the literature still lacks analyses of the postoperative influence of BiPAP on the modulation of the autonomic nervous system after cardiac surgery. This study aimed to evaluate the effects of BiPAP on peripheral oxygen saturation, vital signs, and autonomic balance during hospitalization after cardiac surgery. This randomized controlled trial evaluated 36 patients before and after surgery. The BiPAP group was treated in two 20-minute daily sessions of routine physical therapy since 18 hours after surgery until discharge. The control group received routine physical therapy during the same period. Our primary outcome was peripheral oxygen saturation. Secondary outcomes were vital signs and autonomic balance evaluated by heart rate variability. We observed that peripheral oxygen saturation and blood pressure were unaffected at hospital discharge. Both groups showed a similar increase in heart and respiratory rates. The BiPAP group showed a reduction of the low sympathetic frequency component in −27.1 n.u. (95% CI: −39 to −15.2), increase of high parasympathetic frequency in 27.1 n.u. (95% CI: 15.2 to 39), and an improvement to the LF/HF ratio in −2.5 (95% CI: −3.8 to −1.2), when compared to the control group. BiPAP attenuated sympathetic activity and improved vagal modulation and autonomic balance at hospital discharge. These findings evidence that BiPAP enables more efficient autonomic mechanisms during hospitalization after cardiac surgery.
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Latremouille S, Bhuller M, Shalish W, Sant'Anna G. Cardiorespiratory effects of NIV-NAVA, NIPPV, and NCPAP shortly after extubation in extremely preterm infants: A randomized crossover trial. Pediatr Pulmonol 2021; 56:3273-3282. [PMID: 34379891 DOI: 10.1002/ppul.25607] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/05/2021] [Accepted: 07/29/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Investigate the cardiorespiratory effects of noninvasive neurally adjusted ventilatory assist (NIV-NAVA), nonsynchronized nasal intermittent positive pressure ventilation (NIPPV), and nasal continuous positive airway pressure (NCPAP) shortly after extubation. HYPOTHESIS Types of noninvasive pressure support and the presence of synchronization may affect cardiorespiratory parameters. STUDY DESIGN Randomized crossover trial. PATIENT-SUBJECT SELECTION Infants with birth weight (BW) 1250 g or under, undergoing their first planned extubation were randomly assigned to all three modes using a computer-generated sequence. METHODOLOGY Electrocardiogram and electrical activity of the diaphragm (Edi) were recorded for 30 min on each mode. Analysis of heart rate variability (HRV), diaphragmatic activity (Edi area, breath area, amplitude, inspiratory and expiratory times), and respiratory variability were compared between modes. RESULTS Twenty-three infants had full data recordings and analysis: Median (IQR) gestational age = 25.9 weeks (25.2-26.4), BW = 760 g (595-900), and postnatal age 7 (4-19) days. There were no differences in HRV between modes. A significantly reduced Edi area and breath amplitude, and increased coefficient of variation (CV) of breath amplitude were observed during NIV-NAVA and NIPPV compared to NCPAP. A higher proportion of assisted breaths (99% vs. 51%; p < .001) provided a higher mean airway pressure (MAP; 9.4 vs. 8.2 cmH2 O; p = .002) with lower peak inflation pressures (PIPs; 14 vs. 16 cmH2 O; p < .001) during NIV-NAVA compared to NIPPV. CONCLUSIONS NIV-NAVA and NIPPV applied shortly after extubation were associated with lower respiratory efforts and higher respiratory variability. These effects were more evident for NIV-NAVA where optimal patient-ventilator synchronization provided a higher MAP with lower PIPs.
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Affiliation(s)
- Samantha Latremouille
- Division of Experimental Medicine, McGill University Health Center, Montreal, Quebec, Canada
| | - Monica Bhuller
- Division of Experimental Medicine, McGill University Health Center, Montreal, Quebec, Canada
| | - Wissam Shalish
- Division of Neonatology, McGill University Health Center, Montreal, Quebec, Canada
| | - Guilherme Sant'Anna
- Division of Neonatology, McGill University Health Center, Montreal, Quebec, Canada
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Latremouille S, Shalish W, Kanbar L, Lamer P, Rao S, Kearney RE, Sant'Anna GM. The effects of nasal continuous positive airway pressure and high flow nasal cannula on heart rate variability in extremely preterm infants after extubation: A randomized crossover trial. Pediatr Pulmonol 2019; 54:788-796. [PMID: 30816025 DOI: 10.1002/ppul.24284] [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: 09/10/2018] [Accepted: 01/22/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND NCPAP and High flow nasal cannula (HFNC) are common modes of non-invasive respiratory support used after extubation. Heart rate variability (HRV) has been demonstrated as a marker of well-being in neonates and differences in HRV were described in preterm infants receiving respiratory care. The objective was to investigate the effects of NCPAP and HFNC on HRV after extubation. METHODS Randomized crossover trial in infants with birth weight (BW) ≤1250 g after undergoing their first elective extubation. ECG recordings were performed during 45 min while on HFNC and nasal continuous positive airway pressure (NCPAP). Time domain, non-linear, and frequency domain parameters were calculated and compared during HFNC and NCPAP using paired nonparametric tests. A secondary analysis was performed in the subgroup of infants that were successfully extubated. RESULTS Thirty infants with median [range] gestational age of 27 weeks [24.1-29.3] and BW of 930 g [610-1220] were studied at 5 days [1-39] of age. No differences in HRV parameters were observed between HFNC and NCPAP. In the secondary analysis, infants successfully extubated (n = 27) had a significantly higher HRV during HFNC for some time domain parameters. For instance, the standard deviation of the RR intervals (SDRR) was more likely to be higher during HFNC compared to NCPAP (HFNC: 18/27 vs NCPAP: 9/27, P = 0.017) . CONCLUSION During the first hours after extubation, no differences in HRV were detected between HFNC and NCPAP in the overall cohort. However, a significantly higher HRV was noted during HFNC in the subgroup of infants successfully extubated.
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Affiliation(s)
- Samantha Latremouille
- Division of Neonatology, Department of Pediatrics, McGill University Health Center, Montreal, Canada
| | - Wissam Shalish
- Division of Neonatology, Department of Pediatrics, McGill University Health Center, Montreal, Canada
| | - Lara Kanbar
- Department of Biomedical Engineering, McGill University, Montreal, Canada
| | - Philippe Lamer
- Division of Neonatology, Department of Pediatrics, McGill University Health Center, Montreal, Canada
| | - Smita Rao
- Division of Neonatology, Department of Pediatrics, McGill University Health Center, Montreal, Canada
| | - Robert E Kearney
- Department of Biomedical Engineering, McGill University, Montreal, Canada
| | - Guilherme M Sant'Anna
- Division of Neonatology, Department of Pediatrics, McGill University Health Center, Montreal, Canada
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Osier ND, Pham L, Savarese A, Sayles K, Alexander SA. Animal models in genomic research: Techniques, applications, and roles for nurses. Appl Nurs Res 2016; 32:247-256. [PMID: 27969037 PMCID: PMC5161027 DOI: 10.1016/j.apnr.2016.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 07/29/2016] [Accepted: 07/29/2016] [Indexed: 01/04/2023]
Abstract
Animal research has been conducted by scientists for over two millennia resulting in a better understanding of human anatomy, physiology, and pathology, as well as testing of novel therapies. In the molecular genomic era, pre-clinical models represent a key tool for understanding the genomic underpinnings of health and disease and are relevant to precision medicine initiatives. Nurses contribute to improved health by collecting and translating evidence from clinically relevant pre-clinical models. Using animal models, nurses can ask questions that would not be feasible or ethical to address in humans, and establish the safety and efficacy of interventions before translating them to clinical trials. Two advantages of using pre-clinical models are reduced variability between test subjects and the opportunity for precisely controlled experimental exposures. Standardized care controls the effects of diet and environment, while the availability of inbred strains significantly reduces the confounding effects of genetic differences. Outside the laboratory, nurses can contribute to the approval and oversight of animal studies, as well as translation to clinical trials and, ultimately, patient care. This review is intended as a primer on the use of animal models to advance nursing science; specifically, the paper discusses the utility of preclinical models for studying the pathophysiologic and genomic contributors to health and disease, testing interventions, and evaluating effects of environmental exposures. Considerations specifically geared to nurse researchers are also introduced, including discussion of how to choose an appropriate model and controls, potential confounders, as well as legal and ethical concerns. Finally, roles for nurse clinicians in pre-clinical research are also highlighted.
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Affiliation(s)
- Nicole D Osier
- University of Pittsburgh School of Nursing, Pittsburgh, PA 15213; Safar Center for Resuscitation Research, Pittsburgh, PA 15213
| | - Lan Pham
- University of Pittsburgh School of Nursing, Pittsburgh, PA 15213
| | - Amanda Savarese
- University of Pittsburgh School of Nursing, Pittsburgh, PA 15213
| | - Kendra Sayles
- University of Pittsburgh School of Nursing, Pittsburgh, PA 15213; McGowan Institute for Regenerative Medicine, Pittsburgh, PA, 15260
| | - Sheila A Alexander
- University of Pittsburgh School of Nursing, Pittsburgh, PA 15213; University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.
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Hammash MH, Moser DK, Frazier SK, Lennie TA, Hardin-Pierce M. Heart rate variability as a predictor of cardiac dysrhythmias during weaning from mechanical ventilation. Am J Crit Care 2015; 24:118-27. [PMID: 25727271 DOI: 10.4037/ajcc2015318] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
BACKGROUND Weaning from mechanical ventilation to spontaneous breathing is associated with changes in the hemodynamic and autonomic nervous systems that are reflected by heart rate variability. Although cardiac dysrhythmias are an important manifestation of hemodynamic alterations, the impact of heart rate variability on the occurrence of dysrhythmias during weaning has not been specifically studied. OBJECTIVES To describe differences in heart rate variability spectral power and occurrence of cardiac dysrhythmias at baseline and during the initial trial of weaning from mechanical ventilation and to evaluate the impact of heart rate variability during weaning on occurrence of dysrhythmias. METHOD Continuous 3-lead electrocardiographic recordings were collected from 35 patients receiving mechanical ventilation for 24 hours at baseline and during the initial weaning trial. Heart rate variability was evaluated by using spectral power analysis. RESULTS Low-frequency power increased (P = .04) and high-frequency and very-low-frequency power did not change during weaning. The mean number of supraventricular ectopic beats per hour during weaning was higher than the mean at baseline (P < .001); the mean of ventricular ectopic beats did not change. Low-frequency power was a predictor of ventricular and supraventricular ectopic beats during weaning (P < .001). High-frequency power was predictive of ventricular and supraventricular (P = .02) ectopic beats during weaning. Very-low-frequency power was predictive of ventricular ectopic beats (P < .001) only. CONCLUSION Heart rate variability power spectra during weaning were predictive of dysrhythmias.
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Affiliation(s)
- Muna H. Hammash
- Muna H. Hammash is an assistant professor at the University of Louisville, Louisville, Kentucky. Debra K. Moser and Terry A. Lennie are professors, Susan K. Frazier is an associate professor, and Melanie Hardin-Pierce is an assistant professor at the University of Kentucky, Lexington, Kentucky
| | - Debra K. Moser
- Muna H. Hammash is an assistant professor at the University of Louisville, Louisville, Kentucky. Debra K. Moser and Terry A. Lennie are professors, Susan K. Frazier is an associate professor, and Melanie Hardin-Pierce is an assistant professor at the University of Kentucky, Lexington, Kentucky
| | - Susan K. Frazier
- Muna H. Hammash is an assistant professor at the University of Louisville, Louisville, Kentucky. Debra K. Moser and Terry A. Lennie are professors, Susan K. Frazier is an associate professor, and Melanie Hardin-Pierce is an assistant professor at the University of Kentucky, Lexington, Kentucky
| | - Terry A. Lennie
- Muna H. Hammash is an assistant professor at the University of Louisville, Louisville, Kentucky. Debra K. Moser and Terry A. Lennie are professors, Susan K. Frazier is an associate professor, and Melanie Hardin-Pierce is an assistant professor at the University of Kentucky, Lexington, Kentucky
| | - Melanie Hardin-Pierce
- Muna H. Hammash is an assistant professor at the University of Louisville, Louisville, Kentucky. Debra K. Moser and Terry A. Lennie are professors, Susan K. Frazier is an associate professor, and Melanie Hardin-Pierce is an assistant professor at the University of Kentucky, Lexington, Kentucky
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Vitacca M, Scalvini S, Volterrani M, Clini EM, Paneroni M, Giordano A, Ambrosino N. In COPD patients on prolonged mechanical ventilation heart rate variability during the T-piece trial is better after pressure support plus PEEP: A pilot physiological study. Heart Lung 2014; 43:420-6. [DOI: 10.1016/j.hrtlng.2014.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/02/2014] [Accepted: 04/04/2014] [Indexed: 10/25/2022]
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Abstract
Weaning patients from mechanical ventilation has been compared to a cardiac stress test. Weaning failure (WF) from a cardiac origin can be common in patients with limited cardiac reserve. Diuretic and vasodilator therapies are indicated for WF due to excessive preload, afterload, or myocardial ischemia. Alteration in intrathoracic pressure and lung volumes may also impact weaning process in a patient with poor cardiac function. Noninvasive ventilation decreases cardiac stress load and should be utilized in weaning patients with poor cardiac reserves. In fact, positive pressure therapy is now the standard of care for treating a patient with acute pulmonary edema and to decrease afterload (Frazier et al. Biol Res Nurs 2000; 1(4): 253-264; Pinsky MR. Chest 2005; 128(5 Suppl 2): 592S-597S.). Recently, biomarkers and echocardiography have been utilized to assess weaning success during spontaneous breathing trials. In this article, we describe the physiological alterations in cardiac and pulmonary systems during the weaning process and its impact on weaning outcome.
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Affiliation(s)
- Jahan Porhomayon
- VA Western New York Healthcare System, Division of Critical Care Medicine, Department of Anesthesiology and Medicine, State University of New York, Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY, USA
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Huang CT, Tsai YJ, Lin JW, Ruan SY, Wu HD, Yu CJ. Application of heart-rate variability in patients undergoing weaning from mechanical ventilation. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:R21. [PMID: 24456585 PMCID: PMC4056081 DOI: 10.1186/cc13705] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 01/20/2014] [Indexed: 01/08/2023]
Abstract
Introduction The process of weaning may impose cardiopulmonary stress on ventilated patients. Heart-rate variability (HRV), a noninvasive tool to characterize autonomic function and cardiorespiratory interaction, may be a promising modality to assess patient capability during the weaning process. We aimed to evaluate the association between HRV change and weaning outcomes in critically ill patients. Methods This study included 101 consecutive patients recovering from acute respiratory failure. Frequency-domain analysis, including very low frequency, low frequency, high frequency, and total power of HRV was assessed during a 1-hour spontaneous breathing trial (SBT) through a T-piece and after extubation after successful SBT. Results Of 101 patients, 24 (24%) had SBT failure, and HRV analysis in these patients showed a significant decrease in total power (P = 0.003); 77 patients passed SBT and were extubated, but 13 (17%) of them required reintubation within 72 hours. In successfully extubated patients, very low frequency and total power from SBT to postextubation significantly increased (P = 0.003 and P = 0.004, respectively). Instead, patients with extubation failure were unable to increase HRV after extubation. Conclusions HRV responses differ between patients with different weaning outcomes. Measuring HRV change during the weaning process may help clinicians to predict weaning results and, in the end, to improve patient care and outcome.
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Failed weaning from mechanical ventilation and cardiac dysfunction. Crit Care Res Pract 2012; 2012:173527. [PMID: 22991658 PMCID: PMC3443576 DOI: 10.1155/2012/173527] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 08/03/2012] [Indexed: 11/17/2022] Open
Abstract
Failure to transition patient from controlled mechanical ventilation to spontaneous breathing trials (SBTs) in a timely fashion is associated with significant morbidity and mortality in the intensive care unit. In addition, weaning failures are common in patients with limited cardiac reserves. Recent advances in cardiac echocardiography and laboratory measurement of serum biomarkers to assess hemodynamic response to SBT may provide additional information to guide clinicians to predict weaning outcome.
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Kufoy E, Palma JA, Lopez J, Alegre M, Urrestarazu E, Artieda J, Iriarte J. Changes in the heart rate variability in patients with obstructive sleep apnea and its response to acute CPAP treatment. PLoS One 2012; 7:e33769. [PMID: 22438995 PMCID: PMC3306298 DOI: 10.1371/journal.pone.0033769] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Accepted: 02/16/2012] [Indexed: 01/28/2023] Open
Abstract
Introduction Obstructive Sleep Apnea (OSA) is a major risk factor for cardiovascular disease. The goal of this study was to demonstrate whether the use of CPAP produces significant changes in the heart rate or in the heart rate variability of patients with OSA in the first night of treatment and whether gender and obesity play a role in these differences. Methods Single-center transversal study including patients with severe OSA corrected with CPAP. Only patients with total correction after CPAP were included. Patients underwent two sleep studies on consecutive nights: the first night a basal study, and the second with CPAP. We also analyzed the heart rate changes and their relationship with CPAP treatment, sleep stages, sex and body mass index. Twenty-minute segments of the ECG were selected from the sleep periods of REM, no-REM and awake. Heart rate (HR) and heart rate variability (HRV) were studied by comparing the R-R interval in the different conditions. We also compared samples from the basal study and CPAP nights. Results 39 patients (15 females, 24 males) were studied. The mean age was 50.67 years old, the mean AHI was 48.54, and mean body mass index was 33.41 kg/m2 (31.83 males, 35.95 females). Our results showed that HRV (SDNN) decreased after the use of CPAP during the first night of treatment, especially in non-REM sleep. Gender and obesity did not have any influence on our results. Conclusions These findings support that cardiac variability improves as an acute effect, independently of gender or weight, in the first night of CPAP use in severe OSA patients, supporting the idea of continuous use and emphasizing that noncompliance of CPAP treatment should be avoided even if it is just once.
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Affiliation(s)
- Ernesto Kufoy
- Clinical Neurophysiology Service, University Clinic of Navarra, Pamplona, Spain
| | - Jose-Alberto Palma
- Clinical Neurophysiology Service, University Clinic of Navarra, Pamplona, Spain
- Department of Neurology, University Clinic of Navarra, Pamplona, Spain
| | - Jon Lopez
- Neurophysiology Laboratory, Neurosciences Area, Centro de Investigación Médica Aplicada (CIMA), University of Navarra, Pamplona, Spain
| | - Manuel Alegre
- Clinical Neurophysiology Service, University Clinic of Navarra, Pamplona, Spain
- Neurophysiology Laboratory, Neurosciences Area, Centro de Investigación Médica Aplicada (CIMA), University of Navarra, Pamplona, Spain
| | - Elena Urrestarazu
- Clinical Neurophysiology Service, University Clinic of Navarra, Pamplona, Spain
- Neurophysiology Laboratory, Neurosciences Area, Centro de Investigación Médica Aplicada (CIMA), University of Navarra, Pamplona, Spain
| | - Julio Artieda
- Clinical Neurophysiology Service, University Clinic of Navarra, Pamplona, Spain
- Neurophysiology Laboratory, Neurosciences Area, Centro de Investigación Médica Aplicada (CIMA), University of Navarra, Pamplona, Spain
| | - Jorge Iriarte
- Clinical Neurophysiology Service, University Clinic of Navarra, Pamplona, Spain
- * E-mail:
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Interrelations entre ventilation mécanique et système nerveux autonome. MEDECINE INTENSIVE REANIMATION 2011. [DOI: 10.1007/s13546-011-0218-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Pantoni C, Di Thommazo L, Mendes R, Catai A, Luzzi S, Amaral Neto O, Borghi-Silva A. Effects of different levels of positive airway pressure on breathing pattern and heart rate variability after coronary artery bypass grafting surgery. Braz J Med Biol Res 2011; 44:38-45. [DOI: 10.1590/s0100-879x2010007500129] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2010] [Accepted: 10/29/2010] [Indexed: 11/21/2022] Open
Affiliation(s)
| | | | | | - A.M. Catai
- Universidade Federal de São Carlos, Brasil
| | - S. Luzzi
- Irmandade da Santa Casa de Misericórdia de Araraquara, Brasil
| | - O. Amaral Neto
- Irmandade da Santa Casa de Misericórdia de Araraquara, Brasil
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Pantoni CBF, Mendes RG, Di Thommazo L, Catai AM, Sampaio LMM, Borghi-Silva A. Acute application of bilevel positive airway pressure influences the cardiac autonomic nervous system. Clinics (Sao Paulo) 2009; 64:1085-92. [PMID: 19936182 PMCID: PMC2780525 DOI: 10.1590/s1807-59322009001100008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Accepted: 08/06/2009] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION Noninvasive positive pressure has been used to treat several diseases. However, the physiological response of the cardiac autonomic system during bilevel positive airway pressure (Bilevel) remains unclear. OBJECTIVE The aim of this study was to evaluate the heart rate variability (HRV) during Bilevel in young healthy subjects. METHODS Twenty men underwent 10-minute R-R interval recordings during sham ventilation (SV), Bilevel of 8-15 cmH(2)O and Bilevel of 13-20 cmH(2)O. The HRV was analyzed by means of the parallel R-R interval (mean R-Ri), the standard deviation of all R-Ri (SDNN), the root mean square of the squares of the differences between successive R-Ri (rMSSD), the number of successive R-Ri pairs that differ by more than 50 milliseconds (NN50), the percentage of successive R-Ri that differ by more than 50 milliseconds (pNN50), the low frequency (LF), the high frequency (HF) and SD1 and SD2. Additionally, physiological variables, including blood pressure, breathing frequency and end tidal CO(2), were collected. Repeated-measures ANOVA and Pearson correlation were used to assess the differences between the three studied conditions and the relationships between the delta of Bilevel at 13-20 cmH(2)O and sham ventilation of the HRV indexes and the physiological variables, respectively. RESULTS The R-Ri mean, rMSSD, NN50, pNN50 and SD1 were reduced during Bilevel of 13-20 cmH(2)O as compared to SV. An R-Ri mean reduction was also observed in Bilevel of 13-20 cmH(2)O compared to 8-15 cmH(2)O. Both the R-Ri mean and HF were reduced during Bilevel of 8-15 cmH(2)O as compared to SV, while the LF increased during application of Bilevel of 8-15 cmH(2)O as compared to SV. The delta (between Bilevel at 13-20 cmH(2)O and sham ventilation) of ETCO(2) correlated positively with LF, HF, the LF/HF ratio, SDNN, rMSSD and SD1. Acute application of Bilevel was able to alter the cardiac autonomic nervous system, resulting in a reduction in parasympathetic activity and an increase in sympathetic activity and higher level of positive pressure can cause a greater influence on the cardiovascular and respiratory system.
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Affiliation(s)
- Camila Bianca Falasco Pantoni
- Cardiopulmonary Physiotherapy Laboratory, Nucleus of Research in Physical Exercise, Physiotherapy Department - Federal University of São Carlos - São Carlos/SP, Brazil.
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Li D, Chiang AY, Clawson CA, Main BW, Leishman DJ. Heartbeat dynamics in adrenergic blocker treated conscious beagle dogs. J Pharmacol Toxicol Methods 2008; 58:118-28. [DOI: 10.1016/j.vascn.2008.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Accepted: 05/02/2008] [Indexed: 10/22/2022]
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Borghi-Silva A, Reis MS, Mendes RG, Pantoni CBF, Simões RP, Martins LEB, Catai AM. Noninvasive ventilation acutely modifies heart rate variability in chronic obstructive pulmonary disease patients. Respir Med 2008; 102:1117-23. [PMID: 18585024 DOI: 10.1016/j.rmed.2008.03.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 03/12/2008] [Accepted: 03/16/2008] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The purpose of present study was to evaluate the acute effects of bi-level positive airway pressure (BiPAP) on heart rate variability (HRV) of stable chronic obstructive pulmonary disease patients (COPD). METHODS Nineteen males with COPD (69+/-8 years and with forced expiratory volume in 1s <50% of predicted) and eight healthy sedentary age-matched (69 years) males in the control group (CG) were evaluated during two conditions of controlled respiratory rate: spontaneous breathing (SB) and BiPAP (inspiratory and expiratory levels between 12-14 cmH(2)O and 4-6 cmH(2)O, respectively). Peripheral oxygen saturation (SpO(2)), end-tidal of carbon dioxide (ETCO(2)), systolic blood pressure (SBP) and R-R interval were obtained. HRV was analyzed by time (RMSSD and SDNN index) and frequency domains (high frequency - HF, low frequency - LF and HF/LF ratio). RESULTS Significant reduction of ETCO(2) and SBP in both groups and increase of SpO(2) in COPD group was observed during BiPAP ventilation (p<0.05). During spontaneous breathing, patients with COPD presented lower values of LF, LF/HF and higher values of HF when compared to CG (p<0.05). However, HF was significantly reduced and LF increased during BiPAP ventilation (58+/-19-48+/-15 and 41+/-19-52+/-15 un, respectively) in COPD group. Significant correlations between delta BiPAP-SB (Delta) ETCO(2) and DeltaHF were found (r=0.89). CONCLUSIONS Sympathetic and parasympathetic neural control of heart rate is altered in COPD patients and that BiPAP acutely improves ventilation, enhances sympathetic response and decreases vagal tonus. The improvement of ventilation caused by BiPAP was associated with reduced cardiac vagal activity in stable moderate-to-severe COPD patients.
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Affiliation(s)
- Audrey Borghi-Silva
- Cardiopulmonary Physiotherapy Laboratory, Nucleus of Research in Physical Exercise, Department of Physiotherapy, Federal University of São Carlos, UFSCar, Rodovia Washington Luis, São Carlos, SP, Brazil.
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Frazier SK, Moser DK, Schlanger R, Widener J, Pender L, Stone KS. Autonomic tone in medical intensive care patients receiving mechanical ventilation and during a CPAP weaning trial. Biol Res Nurs 2008; 9:301-10. [PMID: 18398225 DOI: 10.1177/1099800408314707] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Mechanical ventilator support and the resumption of spontaneous ventilation or weaning create significant alterations in alveolar and intrathoracic pressure that influence thoracic blood volume and flow. Compensatory autonomic tone alterations occur to ensure adequate tissue oxygen delivery, but autonomic responses may produce cardiovascular dysfunction with subsequent weaning failure. The authors describe autonomic responses of critically ill patients (n = 43) during a 24-hr period of mechanical ventilatory support and during the 24 hr that included their initial spontaneous breathing trial using continuous positive airway pressure. Nearly two thirds of these patients demonstrated abnormal autonomic function and this dysfunction was more severe in those patients who were unable to sustain spontaneous ventilation (n = 15). With further systematic study, autonomic responses may be useful in the identification of patients who are likely to develop cardiac dysfunction with the resumption of spontaneous breathing.
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Affiliation(s)
- Susan K Frazier
- University of Kentucky College of Nursing, Lexington, KY 40536-0232, USA.
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Abstract
Because of their anatomic position in the closed thoracic cavity, the heart and lungs interact during each ventilation cycle. The application of mechanical ventilation and subsequent removal changes normal ventilatory mechanics and produces alterations in cardiac preload and afterload that influence global hemodynamic state and delivery of oxygen and nutrients. Adverse cardiovascular responses to mechanical ventilation and weaning from ventilation include hemodynamic alterations and instability, myocardial ischemia, autonomic dysfunction, and cardiac dysrhythmias. Clinicians must have a clear understanding of the cardiovascular effects of mechanical ventilation and weaning so they may anticipate, recognize, and effectively manage negative effects and improve patient outcomes.
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Mochizuki H, Okahashi S, Ugawa Y, Tamura T, Suzuki M, Miyatake S, Shigeyama T, Ogata K, Kawai M. Heart rate variability and hypercapnia in Duchenne muscular dystrophy. Intern Med 2008; 47:1893-7. [PMID: 18981633 DOI: 10.2169/internalmedicine.47.1118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE To investigate the relationship between heart rate variability and hypercapnia. PATIENTS AND METHODS We measured the coefficient of variation of R-R interval (CVrr) and arterial blood gas pressures in 73 patients with Duchenne muscular dystrophy. RESULTS CVrr was negatively correlated with arterial partial pressure of carbon dioxide (PaCO(2)). In patients whose CVrr was larger than 5%, 84% of them had no hypercapnia while the other 16% had hypercapnia (PaCO(2) >45 mmHg). In contrast, 27% of those with CVrr smaller than 3% had no hypercapnia, 73% had hypercapnia and 47% had severe hypercapnia (PaCO(2) >50 mmHg). CONCLUSION We first showed that CVrr was negatively correlated with PaCO(2), and propose that abnormally low CVrr indicates respiratory insufficiency in patients with Duchenne muscular dystrophy.
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DEPRESSED HEART RATE VARIABILITY IS ASSOCIATED WITH HIGH IL-6 BLOOD LEVEL AND DECLINE IN THE BLOOD PRESSURE IN SEPTIC PATIENTS. Shock 2007. [DOI: 10.1097/shk.0b013e318063e8d1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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DEPRESSED HEART RATE VARIABILITY IS ASSOCIATED WITH HIGH IL-6 BLOOD LEVEL AND DECLINE IN THE BLOOD PRESSURE IN SEPTIC PATIENTS. Shock 2007; 28:549-53. [DOI: 10.1097/shk.0b013e3180638d1] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Garet M, Barthélémy JC, Degache F, Pichot V, Duverney D, Roche F. Modulations of human autonomic function induced by positive pressure-assisted breathing. Clin Physiol Funct Imaging 2006; 26:15-20. [PMID: 16398665 DOI: 10.1111/j.1475-097x.2005.00645.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In order to examine the acute autonomic response in humans during and immediately after positive pressure-assisted (PPA) breathing, spontaneous cardiac baroreflex (BR) sensitivity was studied through the adaptation of consecutive RR intervals in response to spontaneous systolic blood pressure fluctuations in 11 healthy subjects. The gain (alpha-index) in baroreceptor reflex was estimated using cross-spectral analysis (RR interval variability and systolic blood pressure variability) for the low frequency (LF) and high frequency (HF) bands. All measurements were made under fixed breathing rate (12 breaths per minute), and realized consecutively at baseline level (20 min), after-short inspiratory pressure support plus positive end-expiratory airway pressure (IPS + PEEP) ventilation (15 min), again under normal conditions (20 min; recovery period) and, finally, during a standard upward orthostatic challenge test (15 min; orthostatic challenge). The spontaneous BR gain in the HF band increases slightly during ventilation (+26.1 +/- 11.7%, P<0.05) and decreases significantly during recovery without any significant alteration in mean heart rate, systolic or diastolic blood pressure. The spontaneous BR gain in the LF band decreases during IPS + PEEP ventilation (8.4 +/- 4.4 versus 12.7 +/- 6.2 ms mm(-1) Hg; P<0.05) and returns to basal level during recovery. Orthostatic challenge altered significantly the BR gain in both HF and LF bands with significant heart rate acceleration. In humans, while the parasympathetic control of heart rate and blood pressure is found moderately enhanced, the sympathetic BR drive appears significantly and transitory altered under short term IPS + PEEP ventilation with a degree of alteration comparable to those observed during orthostatic challenge.
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Affiliation(s)
- Martin Garet
- Laboratoire de Physiologie - Groupe de Recherche PPEH, Association de Recherche SYNAPSE, Service de Physiologie Clinique et de l'Exercice, CHU Nord, Saint-Etienne, Université Jean Monnet, Saint-Etienne, France
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Harada T, Abe J, Shiotani M, Hamada Y, Horii I. EFFECT OF AUTONOMIC NERVOUS FUNCTION ON QT INTERVAL IN DOGS. J Toxicol Sci 2005; 30:229-37. [PMID: 16141656 DOI: 10.2131/jts.30.229] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The effects of drugs on the QT interval should be evaluated precisely in the early stages of drug development because QT prolongation can trigger the so-called torsades de pointes, a life-threatening polymorphic ventricular tachycardia. It has been reported that the QT interval is affected by autonomic nervous tone besides the heart rate. In this study, we investigated the direct effect of autonomic nervous tone on the QT interval using the parameters of heart rate variability in dogs, when the RR interval was constant (400 or 700 msec). Our results showed that the QT interval at the high HF (high vagal tone) or low LF/HF ratio (low sympathetic tone) was longer than that at the low HF (low vagal tone) or high LF/HF ratio (high sympathetic tone), when the RR intervals were constant, and that the effect of vagal tone on the QT interval might be somewhat stronger than that of the sympathetic tone. The present observations would support the idea that sympathetic as well as parasympathetic tone regulates QT interval and that QT interval may be controlled physiologically by myocardial autonomic nerves via and not via a sinus node. Therefore, a more precise correction formula of QT interval could be established using autonomic parameters other than RR interval (heart rate), while the QT interval is widely known to be dependent on the RR interval or heart rate.
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Affiliation(s)
- Takuma Harada
- Worldwide Safety Sciences, Pfizer Global Research and Development, Nagoya Laboratories, Pfizer Japan Inc
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Shen HN, Lin LY, Chen KY, Kuo PH, Yu CJ, Wu HD, Yang PC. Changes of heart rate variability during ventilator weaning. Chest 2003; 123:1222-8. [PMID: 12684315 DOI: 10.1378/chest.123.4.1222] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
STUDY OBJECTIVES Despite the recognition that ventilator weaning is associated with a change in autonomic nervous system activity, there has not been any report concerning the change of heart rate variability (HRV), a reliable method to detect autonomic nervous system activity, in patients during weaning. The aim of this study was to investigate the change of autonomic nervous system activity during ventilator weaning by HRV analysis. DESIGN Prospective study. SETTING A 16-bed medical ICU of a tertiary university hospital. PATIENTS Twenty-four patients receiving mechanical ventilation were included. Twelve patients with successful extubation after a spontaneous breathing trial (SBT) [T-piece trial] were classified as the success group; otherwise, the patients were placed in the failure group. INTERVENTIONS None. MEASUREMENTS AND RESULTS Variables, including the total power (TP), and the high-frequency (HF) and low-frequency (LF) components of HRV, were measured in three phases: assist/control mandatory ventilation, pressure support ventilation (PSV), and SBT. While shifting from PSV to SBT, the HRV components decreased significantly in the failure group (TP, p = 0.025; LF, p = 0.007; HF, p = 0.031), but not in the success group. CONCLUSIONS By HRV analysis, reduced HRV and vagal withdrawal of the autonomic nervous system activity are the main changes in patients with weaning failure.
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Affiliation(s)
- Hsiu-Nien Shen
- Department of Internal Medicine, En-Chu-Kong Hospital, Taipei, Taiwan
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Smith SL. Heart Period Variability of Intubated Very-Low-Birth-Weight Infants During Incubator Care and Maternal Holding. Am J Crit Care 2003. [DOI: 10.4037/ajcc2003.12.1.54] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
• Background Heart rate has been used to measure infants’ physiological stability during skin-to-skin holding. Variability in heart period (interbeat interval), a more sensitive measure of autonomic nervous system tone, has not.
• Objective To describe heart period variability in intubated very-low-birth-weight infants during incubator care and during maternal skin-to-skin holding.
• Design/Methods An experimental, interrupted time series, crossover design was used; infants served as their own controls. Infants were randomly assigned to treatment order: 2 hours of intermittent skin-to-skin holding for 2 consecutive days followed by 2 days of incubator care or vice versa. The analog signal representing heart period was sampled and quantized at 5 Hz via a dedicated computer system in multiple 300-second epochs each day.
• Results Fourteen infants with similar characteristics completed the protocol. The mean interbeat interval was 332 ms during skin-to-skin care and 368 ms during incubator care. Power within the low-and high-frequency regions of heart period was not significantly different between skin-to-skin holding and incubator care. Mean low-frequency power was 124.6 ms2 during skin-to-skin holding and ranged from 51.9 ms2 to 71.4 ms2 during all periods of incubator care. Mean high-frequency power was similar during skin-to-skin holding and incubator care (8.8 ms2 and 6.1 ms2). Infants of 32 to 34 weeks’ corrected gestational age had increased power in the low- and high-frequency regions.
• Conclusions Heart period variability did not improve during skin-to-skin holding. Gestationally older infants had increased power in the low- and high-frequency regions, suggesting a maturing autonomic nervous system.
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Abstract
Mechanical ventilation is a life-supporting process employed in the management of respiratory failure. Over the years, our understanding of the pathophysiology of lung injury has greatly improved, and has aided the technological development of ventilatory modes that are more patient 'sensitive' and less traumatizing to the lungs. This review will discuss the fundamental modes of mechanical ventilation, and present current concepts regarding patient-ventilator interaction that either promote lung healing and weaning from positive pressure ventilation or delay recovery because of the injudicious use of ventilatory modalities that are incapable of meeting the ventilatory demands of the patient on a breath-by-breath basis. In addition, the current strategy for mechanical ventilation in acute lung injury and acute respiratory distress syndrome will be summarized.
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Affiliation(s)
- Manuel Fontes
- The Weill Medical College of Cornell University, New York Presbyterian Hospital, New York 10021, USA.
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