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Prosperi P, Verratti V, Taverna A, Rua R, Bonan S, Rapacchiale G, Bondi D, Di Giulio C, Lorkowski J, Spacone A. Ventilatory function and oxygen delivery at high altitude in the Himalayas. Respir Physiol Neurobiol 2023:104086. [PMID: 37257573 DOI: 10.1016/j.resp.2023.104086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/22/2023] [Accepted: 05/26/2023] [Indexed: 06/02/2023]
Abstract
This study aimed to evaluate changes in lung function assessed by spirometry and blood gas content in healthy high-altitude sojourners during a trek in the Himalayas. A group of 19 Italian adults (11 males and 8 females, mean age 43 ±15 years, and BMI 24.2 ±3.7kg/m2) were evaluated as part of a Mount Everest expedition in Nepal. Spirometry and arterial blood gas content were evaluated at baseline in Kathmandu (≈1400m), at the Pyramid Laboratory - Observatory (peak altitude of ≈5000m), and on return to Kathmandu 2-3 days after arrival at each site. All participants took 250mg of acetazolamide per os once daily during the ascent. We found that arterial hemoglobin saturation, O2 and CO2 partial pressures, and the bicarbonate level all decreased (in all cases, p<0.001 with R2=0.70-0.90), while pHa was maintained stable at the peak altitude. Forced vital capacity (FVC) remained stable, while forced expiratory volume in 1sec (FEV1) decreased (p=0.010, n2p=0.228), resulting in a lower FEV1/FVC ratio (p<0.001, n2p=0.380). The best predictor for acute mountain sickness was the O2 partial pressure at the peak altitude (p=0.004, R2=0.39). Finger pulse oximetry overestimated peripheral saturation relative to arterial saturation. We conclude that high-altitude hypoxia alters the respiratory function and the oxygen saturation of the arterial blood hemoglobin. Additionally, air rarefaction and temperature reduction, favoring hypoxic bronchoconstriction, could affect respiration. Pulse oximetry seems not enough to assist medical decisions at high altitudes.
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Affiliation(s)
- Pierpaolo Prosperi
- Department of Pneumology and Respiratory Physiopathology, S. Spirito Hospital, 66020 Pescara, Italy.
| | - Vittore Verratti
- Department of Psychological, Health and Territorial Sciences, 'G. d'Annunzio' University of Chieti-Pescara, 66100 Chieti, Italy.
| | - Alberto Taverna
- Department of Translational Medicine and for Romagna, University of Ferrara, 44121 Ferrara, Italy.
| | - Riccardo Rua
- Department of Anesthesia, Critical Care, and Emergency, University of Turin, 10126 Turin, Italy.
| | - Sofia Bonan
- Department of Medicine and Aging Sciences, 'G. d'Annunzio' University of Chieti-Pescara, 66100 Chieti, Italy.
| | - Giorgia Rapacchiale
- Department of Pneumology and Respiratory Physiopathology, S. Spirito Hospital, 66020 Pescara, Italy.
| | - Danilo Bondi
- Department of Neuroscience, Imaging and Clinical Sciences, 'G. d'Annunzio' University of Chieti-Pescara, 66100 Chieti, Italy.
| | - Camillo Di Giulio
- Department of Neuroscience, Imaging and Clinical Sciences, 'G. d'Annunzio' University of Chieti-Pescara, 66100 Chieti, Italy.
| | - Jacek Lorkowski
- Department of Orthopedics, Traumatology, and Sports Medicine, Central Clinical Hospital of the Ministry of Internal Affairs and Administration, 02-507 Warsaw, Pol.
| | - Antonella Spacone
- Department of Pneumology and Respiratory Physiopathology, S. Spirito Hospital, 66020 Pescara, Italy.
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2
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Fernandes MVS, Müller PDT, Santos MCD, da Silva WA, Güntzel Chiappa AM, Chiappa GR. Ventilatory variability during cardiopulmonary exercise test is higher in heart failure and chronic obstructive pulmonary disease plus heart failure than in chronic obstructive pulmonary disease patients. J Cardiovasc Med (Hagerstown) 2022; 23:694-696. [PMID: 36099077 DOI: 10.2459/jcm.0000000000001327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Marcos V S Fernandes
- Graduate Program in Human Movement and Rehabilitation of Evangelical University of Goiás
| | - Paulo de Tarso Müller
- Federal University of Mato Grosso do Sul (UFMS)/Maria Aparecida Pedrossian Hospital (HUMAP), Laboratory of Respiratory Pathophysiology (LAFIR), Campo Grande, Mato Grosso do Sul, MS
| | | | - Weder Alves da Silva
- Graduate Program in Human Movement and Rehabilitation of Evangelical University of Goiás
| | | | - Gaspar R Chiappa
- Graduate Program in Human Movement and Rehabilitation of Evangelical University of Goiás
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3
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Oku Y. Temporal variations in the pattern of breathing: techniques, sources, and applications to translational sciences. J Physiol Sci 2022; 72:22. [PMID: 36038825 DOI: 10.1186/s12576-022-00847-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 08/12/2022] [Indexed: 11/10/2022]
Abstract
The breathing process possesses a complex variability caused in part by the respiratory central pattern generator in the brainstem; however, it also arises from chemical and mechanical feedback control loops, network reorganization and network sharing with nonrespiratory motor acts, as well as inputs from cortical and subcortical systems. The notion that respiratory fluctuations contain hidden information has prompted scientists to decipher respiratory signals to better understand the fundamental mechanisms of respiratory pattern generation, interactions with emotion, influences on the cortical neuronal networks associated with cognition, and changes in variability in healthy and disease-carrying individuals. Respiration can be used to express and control emotion. Furthermore, respiration appears to organize brain-wide network oscillations via cross-frequency coupling, optimizing cognitive performance. With the aid of information theory-based techniques and machine learning, the hidden information can be translated into a form usable in clinical practice for diagnosis, emotion recognition, and mental conditioning.
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Affiliation(s)
- Yoshitaka Oku
- Division of Physiome, Department of Physiology, Hyogo Medical University, Nishinomiya, Hyogo, 663-8501, Japan.
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4
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Balogh AL, Sudy R, Petak F, Habre W, Dos Santos Rocha A. Sevoflurane and Hypercapnia Blunt the Physiological Variability of Spontaneous Breathing: A Comparative Interventional Study. Front Physiol 2022; 13:871070. [PMID: 35480042 PMCID: PMC9035625 DOI: 10.3389/fphys.2022.871070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/25/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Although spontaneous breathing is known to exhibit substantial physiological fluctuation that contributes to alveolar recruitment, changes in the variability of the respiratory pattern following inhalation of carbon dioxide (CO2) and volatile anesthetics have not been characterized. Therefore, we aimed at comparing the indices of breathing variability under wakefulness, sleep, hypercapnia and sedative and anesthetic concentrations of sevoflurane.Methods: Spontaneous breathing pattern was recorded on two consecutive days in six rabbits using open whole-body plethysmography under wakefulness and spontaneous sleep and following inhalation of 5% CO2, 2% sevoflurane (0.5 MAC) and 4% (1 MAC) sevoflurane. Tidal volume (VT), respiratory rate (RR), minute ventilation (MV), inspiratory time (TI) and mean inspiratory flow (VT/TI) were calculated from the pressure fluctuations in the plethysmograph. Means and coefficients of variation were calculated for each measured variable. Autoregressive model fitting was applied to estimate the relative contributions of random, correlated, and oscillatory behavior to the total variance.Results: Physiological sleep decreased MV by lowering RR without affecting VT. Hypercapnia increased MV by elevating VT. Sedative and anesthetic concentrations of sevoflurane increased VT but decreased MV due to a decrease in RR. Compared to the awake stage, CO2 had no effect on VT/TI while sevoflurane depressed significantly the mean inspiratory flow. Compared to wakefulness, the variability in VT, RR, MV, TI and VT/TI were not affected by sleep but were all significantly decreased by CO2 and sevoflurane. The variance of TI originating from correlated behavior was significantly decreased by both concentrations of sevoflurane compared to the awake and asleep conditions.Conclusions: The variability of spontaneous breathing during physiological sleep and sevoflurane-induced anesthesia differed fundamentally, with the volatile agent diminishing markedly the fluctuations in respiratory volume, inspiratory airflow and breathing frequency. These findings may suggest the increased risk of lung derecruitment during procedures under sevoflurane in which spontaneous breathing is maintained.
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Affiliation(s)
- Adam L. Balogh
- Unit for Anaesthesiological Investigations, Department of Acute Medicine, University of Geneva, Geneva, Switzerland
- *Correspondence: Adam L. Balogh,
| | - Roberta Sudy
- Unit for Anaesthesiological Investigations, Department of Acute Medicine, University of Geneva, Geneva, Switzerland
| | - Ferenc Petak
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Walid Habre
- Unit for Anaesthesiological Investigations, Department of Acute Medicine, University of Geneva, Geneva, Switzerland
| | - Andre Dos Santos Rocha
- Unit for Anaesthesiological Investigations, Department of Acute Medicine, University of Geneva, Geneva, Switzerland
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5
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Straus C, Teulier M, Morel S, Wattiez N, Hajage D, Giboin C, Charbit B, Dasque E, Bodineau L, Chenuel B, Straus N, Attali V, Similowski T. Baclofen destabilises breathing during sleep in healthy humans: A randomised, controlled, double-blind crossover trial. Br J Clin Pharmacol 2020; 87:1814-1823. [PMID: 32986891 DOI: 10.1111/bcp.14569] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/31/2020] [Accepted: 09/13/2020] [Indexed: 11/29/2022] Open
Abstract
AIMS Periodic breathing is frequent in patients with severe heart failure. Apart from being an indicator of severity, periodic breathing has its own deleterious consequences (sleep-related oxygen desaturations, sleep fragmentation), which justifies attempts to correct it irrespective of the underlying disease. Animal models and human data suggest that baclofen can reconfigure respiratory central pattern generators. We hypothesised that baclofen, a GABAB agonist, may thus be able to correct periodic breathing in humans. METHODS Healthy volunteers were exposed to hypoxia during sleep. Participants who developed periodic breathing (n = 14 [53 screened]) were randomly assigned to double-blind oral baclofen (progressively increased to 60 mg/d) or placebo. The primary outcome was the coefficient of variation (CoVar) of respiratory cycle total time considered as an indicator of breathing irregularity. Secondary outcomes included the CoVar of tidal volume, apnoea-hypopnoea index, sleep fragmentation index and ventilatory complexity (noise limit). RESULTS The analysis was conducted in 9 subjects after exclusion of incomplete datasets. CoVar of respiratory cycle total time significantly increased with baclofen during non-rapid eye movement sleep (median with placebo 56.00% [37.63-78.95]; baclofen 85.42% [68.37-86.40], P = .020; significant difference during the N1-N2 phases of sleep but not during the N3 phase). CoVar of tidal volume significantly increased during N1-N2 sleep. The apnoea-hypopnoea index, sleep fragmentation index and ventilatory complexity were not significantly different between placebo and baclofen. CONCLUSION Baclofen did not stabilise breathing in our model. On the contrary, it increased respiratory variability. Baclofen should probably not be used in patients with or at risk of periodic breathing.
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Affiliation(s)
- Christian Straus
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France.,AP-HP, Groupe Hospitalier APHP-Sorbonne Université, Hôpital Pitié-Salpêtrière, Département R3S, Service des Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée, Paris, France
| | - Marion Teulier
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
| | - Sébastien Morel
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
| | - Nicolas Wattiez
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
| | - David Hajage
- Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Pierre Louis d'Epidémiologie et de Santé Publique, AP-HP. Sorbonne Université, Hôpital Pitié Salpêtrière, Département de Santé Publique, Unité de Recherche Clinique Salpêtrière-Charles Foix, Centre de Pharmacoépidémiologie (Cephepi), Sorbonne Université, Paris, France
| | - Caroline Giboin
- AP-HP, Groupe Hospitalier APHP-Sorbonne Université, Hôpital Pitié-Salpêtrière, Unité de Recherche Clinique Salpêtrière-Charles Foix, Paris, France
| | - Beny Charbit
- INSERM and AP-HP, CIC-1901 module Paris-Est, Groupe Hospitalier Universitaire APHP-Sorbonne Université, site Pitié-Salpêtrière, Paris, France.,Department of Anesthesiology and Intensive Care, CHU Reims, Hôpital Robert Debré, Reims, France
| | - Eric Dasque
- INSERM and AP-HP, CIC-1901 module Paris-Est, Groupe Hospitalier Universitaire APHP-Sorbonne Université, site Pitié-Salpêtrière, Paris, France
| | - Laurence Bodineau
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
| | - Bruno Chenuel
- CHRU de Nancy, Service des Explorations Fonctionnelles Respiratoires et Centre Universitaire de Médecine du Sport et Activité Physique Adaptée, Vandoeuvre-lès-Nancy, France.,Faculté de Médecine de Nancy, EA DevAH - Universié de Lorraine, Vandoeuvre-lès-Nancy, France
| | - Nicolas Straus
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
| | - Valérie Attali
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France.,AP-HP, Groupe Hospitalier APHP-Sorbonne Université, Hôpital Pitié-Salpêtrière, Hôpital Pitié-Salpêtrière, Département R3S, Service des Pathologies du Sommeil, Paris, France
| | - Thomas Similowski
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France.,AP-HP, Groupe Hospitalier APHP-Sorbonne Université, Hôpital Pitié-Salpêtrière, Hôpital Pitié-Salpêtrière, Département R3S, Service de Pneumologie, Médecine Intensive et Réanimation, Paris, France
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6
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Betka S, Canzoneri E, Adler D, Herbelin B, Bello-Ruiz J, Kannape OA, Similowski T, Blanke O. Mechanisms of the breathing contribution to bodily self-consciousness in healthy humans: Lessons from machine-assisted breathing? Psychophysiology 2020; 57:e13564. [PMID: 32162704 PMCID: PMC7507190 DOI: 10.1111/psyp.13564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 02/02/2023]
Abstract
Previous studies investigated bodily self-consciousness (BSC) by experimentally exposing subjects to multisensory conflicts (i.e., visuo-tactile, audio-tactile, visuo-cardiac) in virtual reality (VR) that involve the participant's torso in a paradigm known as the full-body illusion (FBI). Using a modified FBI paradigm, we found that synchrony of visuo-respiratory stimulation (i.e., a flashing outline surrounding an avatar in VR; the flash intensity depending on breathing), is also able to modulate BSC by increasing self-location and breathing agency toward the virtual body. Our aim was to investigate such visuo-respiratory effects and determine whether respiratory motor commands contributes to BSC, using non-invasive mechanical ventilation (i.e., machine-delivered breathing). Seventeen healthy participants took part in a visuo-respiratory FBI paradigm and performed the FBI during two breathing conditions: (a) "active breathing" (i.e., participants actively initiate machine-delivered breaths) and (b) "passive breathing" (i.e., breaths' timing was determined by the machine). Respiration rate, tidal volume, and their variability were recorded. In line with previous results, participants experienced subjective changes in self-location, breathing agency, and self-identification toward the avatar's body, when presented with synchronous visuo-respiratory stimulation. Moreover, drift in self-location was reduced and tidal volume variability were increased by asynchronous visuo-respiratory stimulations. Such effects were not modulated by breathing control manipulations. Our results extend previous FBI findings showing that visuo-respiratory stimulation affects BSC, independently from breathing motor command initiation. Also, variability of respiratory parameters was influenced by visuo-respiratory feedback and might reduce breathing discomfort. Further exploration of such findings might inform the development of respiratory therapeutic tools using VR in patients.
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Affiliation(s)
- Sophie Betka
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics & Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Elisa Canzoneri
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics & Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Dan Adler
- Division of Pulmonary Diseases, Geneva University Hospital, Geneva, Switzerland
| | - Bruno Herbelin
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics & Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Javier Bello-Ruiz
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics & Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Oliver Alan Kannape
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics & Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Thomas Similowski
- UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, INSERM, Sorbonne Université, Paris, France.,Département R3S, Service de Pneumologie, Médecine Intensive et Réanimation, AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Paris, France
| | - Olaf Blanke
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics & Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland.,Department of Clinical Neurosciences, Geneva University Hospital, Geneva, Switzerland
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Benghanem S, Mazeraud A, Azabou E, Chhor V, Shinotsuka CR, Claassen J, Rohaut B, Sharshar T. Brainstem dysfunction in critically ill patients. Crit Care 2020; 24:5. [PMID: 31907011 PMCID: PMC6945639 DOI: 10.1186/s13054-019-2718-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 12/23/2019] [Indexed: 02/06/2023] Open
Abstract
The brainstem conveys sensory and motor inputs between the spinal cord and the brain, and contains nuclei of the cranial nerves. It controls the sleep-wake cycle and vital functions via the ascending reticular activating system and the autonomic nuclei, respectively. Brainstem dysfunction may lead to sensory and motor deficits, cranial nerve palsies, impairment of consciousness, dysautonomia, and respiratory failure. The brainstem is prone to various primary and secondary insults, resulting in acute or chronic dysfunction. Of particular importance for characterizing brainstem dysfunction and identifying the underlying etiology are a detailed clinical examination, MRI, neurophysiologic tests such as brainstem auditory evoked potentials, and an analysis of the cerebrospinal fluid. Detection of brainstem dysfunction is challenging but of utmost importance in comatose and deeply sedated patients both to guide therapy and to support outcome prediction. In the present review, we summarize the neuroanatomy, clinical syndromes, and diagnostic techniques of critical illness-associated brainstem dysfunction for the critical care setting.
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Affiliation(s)
- Sarah Benghanem
- Department of Neurology, Neuro-ICU, Sorbonne University, APHP Pitié-Salpêtrière Hospital, Paris, France
- Medical ICU, Cochin Hospital, AP-HP, Paris, France
| | - Aurélien Mazeraud
- Department of Neuro-ICU, GHU-Paris, Paris-Descartes University, Paris, France
- Laboratory of Experimental Neuropathology, Pastuer Institute, Paris, France
| | - Eric Azabou
- Department of Physiology, Clinical Neurophysiology Unit, APHP, Raymond Poincaré Hospital, University of Versailles Saint Quentin en Yvelines, Garches, France
| | - Vibol Chhor
- Department of Intensive Care Medicine, Saint-Joseph Hospital, Paris, France
| | - Cassia Righy Shinotsuka
- Intensive Care Unit and Postgraduate Program, Instituto Nacional de Câncer, Rio de Janeiro, Brazil
- D'Or Institute for Research and Education, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jan Claassen
- Department of Neurology, Neuro-ICU, Columbia University, New York, NY, USA
| | - Benjamin Rohaut
- Department of Neurology, Neuro-ICU, Sorbonne University, APHP Pitié-Salpêtrière Hospital, Paris, France
- Department of Neurology, Neuro-ICU, Columbia University, New York, NY, USA
- Institut du Cerveau et de la Moelle épinière, ICM, INSERM UMRS 1127, CNRS UMR 7225, Pitié- Salpêtrière Hospital, Paris, F-75013, France
| | - Tarek Sharshar
- Department of Neuro-ICU, GHU-Paris, Paris-Descartes University, Paris, France.
- Laboratory of Experimental Neuropathology, Pastuer Institute, Paris, France.
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8
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Young BP, Loparo KA, Dick TE, Jacono FJ. Ventilatory pattern variability as a biometric for severity of acute lung injury in rats. Respir Physiol Neurobiol 2019; 265:161-171. [PMID: 30928542 PMCID: PMC9994622 DOI: 10.1016/j.resp.2019.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 03/05/2019] [Accepted: 03/26/2019] [Indexed: 01/27/2023]
Abstract
We hypothesize that ventilatory pattern variability (VPV) varies with the magnitude of acute lung injury (ALI). In adult male rats, we instilled a low- or high- dose of bleomycin or saline (PBS) intratracheally. While representative samples of pulmonary tissue indicated graded lung injury, coefficient of variation (CV) of TTOT did not differ among the 3 groups. Broncho-alveolar lavage fluid (BALF), respiratory rate (fR), mutual information were greater in ALI than sham rats; but did not differ between bleomycin doses. However, nonlinear complexity index (NLCI), which is the difference in sample entropy between original and surrogate data sets was greater for high- versus low- dose; but did not differ between low-dose and sham groups. Further, NLCI correlated to an injury index based on protein concentration of BALF and failure to gain weight. Finally, Receiver Operator Curves (ROCs) indicated that both mutual information and NLCI had greater sensitivity and specificity than fR and CVTTOT in identifying ALI. Thus, nonlinear analyses of VPV can distinguish ALI and out performs fR as a biometric.
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Affiliation(s)
- Benjamin P Young
- Division of Pulmonary, Critical Care, & Sleep Medicine, Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Kenneth A Loparo
- Department of Electrical Engineering and Computer Science, School of Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Thomas E Dick
- Division of Pulmonary, Critical Care, & Sleep Medicine, Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Neurosciences, School of Medicine Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Frank J Jacono
- Division of Pulmonary, Critical Care, & Sleep Medicine, Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Louis Stokes VA Medical Center, Cleveland, OH 44106, USA
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9
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Niérat MC, Laveneziana P, Dubé BP, Shirkovskiy P, Ing RK, Similowski T. Physiological Validation of an Airborne Ultrasound Based Surface Motion Camera for a Contactless Characterization of Breathing Pattern in Humans. Front Physiol 2019; 10:680. [PMID: 31191363 PMCID: PMC6549521 DOI: 10.3389/fphys.2019.00680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/13/2019] [Indexed: 02/03/2023] Open
Abstract
Characterizing the breathing pattern in naturally breathing humans brings important information on respiratory mechanics, respiratory muscle, and breathing control. However, measuring breathing modifies breathing (observer effect) through the effects of instrumentation and awareness: measuring human breathing under true ecological conditions is currently impossible. This study tested the hypothesis that non-contact vibrometry using airborne ultrasound (SONAR) could measure breathing movements in a contactless and invisible manner. Thus, first, we evaluated the validity of SONAR measurements by testing their interchangeability with pneumotachograph (PNT) measurements obtained at the same time. We also aimed at evaluating the observer effect by comparing breathing variability obtained by SONAR versus SONAR-PNT measurements. Twenty-three healthy subjects (12 men and 11 women; mean age 33 years - range: 20-54) were studied during resting breathing while sitting on a chair. Breathing activity was described in terms of ventilatory flow measured using a PNT and, either simultaneously or sequentially, with a SONAR device measuring the velocity of the surface motion of the chest wall. SONAR was focused either anteriorly on the xiphoid process or posteriorly on the lower part of the costal margin. Discrete ventilatory temporal and volume variables and their coefficients of variability were calculated from the flow signal (PNT) and the velocity signal (SONAR) and tested for interchangeability (Passing-Bablok regression). Tidal volume (VT) and displacement were linearly related. Breathing frequency (BF), total cycle time (TT), inspiratory time (TI), and expiratory time (TE) met interchangeability criteria. Their coefficients of variation were not statistically significantly different with PNT and SONAR-only. This was true for both the anterior and the posterior SONAR measurements. Non-contact vibrometry using airborne ultrasound is a valid tool for measuring resting breathing pattern.
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Affiliation(s)
- Marie-Cécile Niérat
- INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Sorbonne Université, Paris, France
| | - Pierantonio Laveneziana
- INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Sorbonne Université, Paris, France
- Assistance Publique – Hôpitaux de Paris (AP-HP), Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service des Explorations Fonctionnelles de la Respiration, de l’Exercice et de la Dyspnée, Département R3S, Paris, France
| | - Bruno-Pierre Dubé
- INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Sorbonne Université, Paris, France
- Carrefour de l’Innovation et de l’Évaluation en Santé, Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montreal, QC, Canada
| | - Pavel Shirkovskiy
- Institut Langevin, CNRS UMR7587, ESPCI ParisTech, PSL Research University, Paris, France
| | - Ros-Kiri Ing
- Institut Langevin, CNRS UMR7587, ESPCI ParisTech, PSL Research University, Paris, France
| | - Thomas Similowski
- INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Sorbonne Université, Paris, France
- Assistance Publique – Hôpitaux de Paris (AP-HP), Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie, Médecine Intensive et Réanimation, Département R3S, Paris, France
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Satalin J, Habashi NM, Nieman GF. Never give the lung the opportunity to collapse. TRENDS IN ANAESTHESIA AND CRITICAL CARE 2018. [DOI: 10.1016/j.tacc.2018.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Oppersma E, Doorduin J, van der Hoeven JG, Veltink PH, van Hees HWH, Heunks LMA. The effect of metabolic alkalosis on the ventilatory response in healthy subjects. Respir Physiol Neurobiol 2018; 249:47-53. [PMID: 29307724 DOI: 10.1016/j.resp.2018.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/07/2017] [Accepted: 01/03/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND Patients with acute respiratory failure may develop respiratory acidosis. Metabolic compensation by bicarbonate production or retention results in posthypercapnic alkalosis with an increased arterial bicarbonate concentration. The hypothesis of this study was that elevated plasma bicarbonate levels decrease respiratory drive and minute ventilation. METHODS In an intervention study in 10 healthy subjects the ventilatory response using a hypercapnic ventilatory response (HCVR) test was assessed, before and after administration of high dose sodium bicarbonate. Total dose of sodiumbicarbonate was 1000 ml 8.4% in 3 days. RESULTS Plasma bicarbonate increased from 25.2 ± 2.2 to 29.2 ± 1.9 mmol/L. With increasing inspiratory CO2 pressure during the HCVR test, RR, Vt, Pdi, EAdi and VE increased. The clinical ratio ΔVE/ΔPetCO2 remained unchanged, but Pdi, EAdi and VE were significantly lower after bicarbonate administration for similar levels of inspired CO2. CONCLUSION This study demonstrates that in healthy subjects metabolic alkalosis decreases the neural respiratory drive and minute ventilation, as a response to inspiratory CO2.
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Affiliation(s)
- E Oppersma
- MIRA - Institute for Biomedical Technology & Technical Medicine, University of Twente, Enschede, The Netherlands; Department of Critical Care Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - J Doorduin
- Department of Critical Care Medicine, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - J G van der Hoeven
- Department of Critical Care Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - P H Veltink
- MIRA - Institute for Biomedical Technology & Technical Medicine, University of Twente, Enschede, The Netherlands
| | - H W H van Hees
- Department of Pulmonary Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - L M A Heunks
- Department of Critical Care Medicine, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Intensive Care Medicine, VU University Medical Center, Amsterdam, The Netherlands.
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12
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Loiseau C, Cayetanot F, Joubert F, Perrin-Terrin AS, Cardot P, Fiamma MN, Frugiere A, Straus C, Bodineau L. Current Perspectives for the use of Gonane Progesteronergic Drugs in the Treatment of Central Hypoventilation Syndromes. Curr Neuropharmacol 2018; 16:1433-1454. [PMID: 28721821 PMCID: PMC6295933 DOI: 10.2174/1570159x15666170719104605] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/30/2017] [Accepted: 07/12/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Central alveolar hypoventilation syndromes (CHS) encompass neurorespiratory diseases resulting from congenital or acquired neurological disorders. Hypercapnia, acidosis, and hypoxemia resulting from CHS negatively affect physiological functions and can be lifethreatening. To date, the absence of pharmacological treatment implies that the patients must receive assisted ventilation throughout their lives. OBJECTIVE To highlight the relevance of determining conditions in which using gonane synthetic progestins could be of potential clinical interest for the treatment of CHS. METHODS The mechanisms by which gonanes modulate the respiratory drive were put into the context of those established for natural progesterone and other synthetic progestins. RESULTS The clinical benefits of synthetic progestins to treat respiratory diseases are mixed with either positive outcomes or no improvement. A benefit for CHS patients has only recently been proposed. We incidentally observed restoration of CO2 chemosensitivity, the functional deficit of this disease, in two adult CHS women by desogestrel, a gonane progestin, used for contraception. This effect was not observed by another group, studying a single patient. These contradictory findings are probably due to the complex nature of the action of desogestrel on breathing and led us to carry out mechanistic studies in rodents. Our results show that desogestrel influences the respiratory command by modulating the GABAA and NMDA signaling in the respiratory network, medullary serotoninergic systems, and supramedullary areas. CONCLUSION Gonanes show promise for improving ventilation of CHS patients, although the conditions of their use need to be better understood.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Laurence Bodineau
- Address correspondence to this author at the Sorbonne Universités, UPMC Univ. Paris 06, INSERM, UMR_S1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75013, Paris, France; Tel: 33 1 40 77 97 15; Fax: 33 1 40 77 97 89; E-mail:
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13
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Niérat MC, Dubé BP, Llontop C, Bellocq A, Layachi Ben Mohamed L, Rivals I, Straus C, Similowski T, Laveneziana P. Measuring Ventilatory Activity with Structured Light Plethysmography (SLP) Reduces Instrumental Observer Effect and Preserves Tidal Breathing Variability in Healthy and COPD. Front Physiol 2017; 8:316. [PMID: 28572773 PMCID: PMC5435806 DOI: 10.3389/fphys.2017.00316] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 05/02/2017] [Indexed: 11/13/2022] Open
Abstract
The use of a mouthpiece to measure ventilatory flow with a pneumotachograph (PNT) introduces a major perturbation to breathing ("instrumental/observer effect") and suffices to modify the respiratory behavior. Structured light plethysmography (SLP) is a non-contact method of assessment of breathing pattern during tidal breathing. Firstly, we validated the SLP measurements by comparing timing components of the ventilatory pattern obtained by SLP vs. PNT under the same condition; secondly, we compared SLP to SLP+PNT measurements of breathing pattern to evaluate the disruption of breathing pattern and breathing variability in healthy and COPD subjects. Measurements were taken during tidal breathing with SLP alone and SLP+PNT recording in 30 COPD and healthy subjects. Measurements included: respiratory frequency (Rf), inspiratory, expiratory, and total breath time/duration (Ti, Te, and Tt). Passing-Bablok regression analysis was used to evaluate the interchangeability of timing components of the ventilatory pattern (Rf, Ti, Te, and Tt) between measurements performed under the following experimental conditions: SLP vs. PNT, SLP+PNT vs. SLP, and SLP+PNT vs. PNT. The variability of different ventilatory variables was assessed through their coefficients of variation (CVs). In healthy: according to Passing-Bablok regression, Rf, TI, TE and TT were interchangeable between measurements obtained under the three experimental conditions (SLP vs. PNT, SLP+PNT vs. SLP, and SLP+PNT vs. PNT). All the CVs describing "traditional" ventilatory variables (Rf, Ti, Te, Ti/Te, and Ti/Tt) were significantly smaller in SLP+PNT condition. This was not the case for more "specific" SLP-derived variables. In COPD: according to Passing-Bablok regression, Rf, TI, TE, and TT were interchangeable between measurements obtained under SLP vs. PNT and SLP+PNT vs. PNT, whereas only Rf, TE, and TT were interchangeable between measurements obtained under SLP+PNT vs. SLP. However, most discrete variables were significantly different between the SLP and SLP+PNT conditions and CVs were significantly lower when COPD patients were assessed in the SLP+PNT condition. Measuring ventilatory activity with SLP preserves resting tidal breathing variability, reduces instrumental observer effect and avoids any disruptions in breathing pattern induced by the use of PNT-mouthpiece-nose-clip combination.
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Affiliation(s)
- Marie-Cécile Niérat
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France
| | - Bruno-Pierre Dubé
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France.,Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département "R3S", Pôle PRAGUES)Paris, France.,Département de Médecine, Service de Pneumologie, Hôpital Hôtel-Dieu du Centre Hospitalier de l'Université de MontréalMontréal, QC, Canada
| | - Claudia Llontop
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France.,Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service des Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée (Département "R3S", Pôle PRAGUES)Paris, France
| | - Agnès Bellocq
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France.,Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service des Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée (Département "R3S", Pôle PRAGUES)Paris, France
| | - Lila Layachi Ben Mohamed
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France.,Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département "R3S", Pôle PRAGUES)Paris, France
| | - Isabelle Rivals
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France.,Equipe de Statistique Appliquée, ESPCI Paris, PSL Research UniversityParis, France
| | - Christian Straus
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France.,Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service des Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée (Département "R3S", Pôle PRAGUES)Paris, France
| | - Thomas Similowski
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France.,Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département "R3S", Pôle PRAGUES)Paris, France
| | - Pierantonio Laveneziana
- Sorbonne Universités, UPMC Université Paris 06, Institut National de la Santé et de la Recherche Médicale, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et CliniqueParis, France.,Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service des Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée (Département "R3S", Pôle PRAGUES)Paris, France
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14
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Dhingra RR, Dutschmann M, Galán RF, Dick TE. Kölliker-Fuse nuclei regulate respiratory rhythm variability via a gain-control mechanism. Am J Physiol Regul Integr Comp Physiol 2016; 312:R172-R188. [PMID: 27974314 DOI: 10.1152/ajpregu.00238.2016] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 11/14/2016] [Accepted: 12/11/2016] [Indexed: 11/22/2022]
Abstract
Respiration varies from breath to breath. On the millisecond timescale of spiking, neuronal circuits exhibit variability due to the stochastic properties of ion channels and synapses. Does this fast, microscopic source of variability contribute to the slower, macroscopic variability of the respiratory period? To address this question, we modeled a stochastic oscillator with forcing; then, we tested its predictions experimentally for the respiratory rhythm generated by the in situ perfused preparation during vagal nerve stimulation (VNS). Our simulations identified a relationship among the gain of the input, entrainment strength, and rhythm variability. Specifically, at high gain, the periodic input entrained the oscillator and reduced variability, whereas at low gain, the noise interacted with the input, causing events known as "phase slips", which increased variability on a slow timescale. Experimentally, the in situ preparation behaved like the low-gain model: VNS entrained respiration but exhibited phase slips that increased rhythm variability. Next, we used bilateral muscimol microinjections in discrete respiratory compartments to identify areas involved in VNS gain control. Suppression of activity in the nucleus tractus solitarii occluded both entrainment and amplification of rhythm variability by VNS, confirming that these effects were due to the activation of the Hering-Breuer reflex. Suppressing activity of the Kölliker-Fuse nuclei (KFn) enhanced entrainment and reduced rhythm variability during VNS, consistent with the predictions of the high-gain model. Together, the model and experiments suggest that the KFn regulates respiratory rhythm variability via a gain control mechanism.
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Affiliation(s)
- Rishi R Dhingra
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Division of Pulmonary, Critical Care & Sleep, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Mathias Dutschmann
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia; and
| | - Roberto F Galán
- Department of Electrical Engineering and Computer Science, School of Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Thomas E Dick
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio; .,Division of Pulmonary, Critical Care & Sleep, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
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15
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Samson N, Praud JP, Quenet B, Similowski T, Straus C. New insights into sucking, swallowing and breathing central generators: A complexity analysis of rhythmic motor behaviors. Neurosci Lett 2016; 638:90-95. [PMID: 27956236 DOI: 10.1016/j.neulet.2016.12.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 11/25/2016] [Accepted: 12/08/2016] [Indexed: 10/20/2022]
Abstract
Sucking, swallowing and breathing are dynamic motor behaviors. Breathing displays features of chaos-like dynamics, in particular nonlinearity and complexity, which take their source in the automatic command of breathing. In contrast, buccal/gill ventilation in amphibians is one of the rare motor behaviors that do not display nonlinear complexity. This study aimed at assessing whether sucking and swallowing would also follow nonlinear complex dynamics in the newborn lamb. Breathing movements were recorded before, during and after bottle-feeding. Sucking pressure and the integrated EMG of the thyroartenoid muscle, as an index of swallowing, were recorded during bottle-feeding. Nonlinear complexity of the whole signals was assessed through the calculation of the noise limit value (NL). Breathing and swallowing always exhibited chaos-like dynamics. The NL of breathing did not change significantly before, during or after bottle-feeding. On the other hand, sucking inconsistently and significantly less frequently than breathing exhibited a chaos-like dynamics. Therefore, the central pattern generator (CPG) that drives sucking may be functionally different from the breathing CPG. Furthermore, the analogy between buccal/gill ventilation and sucking suggests that the latter may take its phylogenetic origin in the gill ventilation CPG of the common ancestor of extant amphibians and mammals.
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Affiliation(s)
- Nathalie Samson
- Neonatal Respiratory Research Unit, Department of Pediatric and Pharmacology-Physiology, Université de Sherbrooke, Qc, Canada
| | - Jean-Paul Praud
- Neonatal Respiratory Research Unit, Department of Pediatric and Pharmacology-Physiology, Université de Sherbrooke, Qc, Canada
| | - Brigitte Quenet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France; Equipe de Statistique Appliquée ESPCI-Paris, PSL Research University, Paris, France
| | - Thomas Similowski
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France; AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), F-75013, Paris, France
| | - Christian Straus
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France; AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service d'Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée (Département R3S), F-75013, Paris, France.
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16
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17
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Bokov P, Fiamma MN, Chevalier-Bidaud B, Chenivesse C, Straus C, Similowski T, Delclaux C. Increased ventilatory variability and complexity in patients with hyperventilation disorder. J Appl Physiol (1985) 2016; 120:1165-72. [DOI: 10.1152/japplphysiol.00859.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/10/2016] [Indexed: 12/18/2022] Open
Abstract
It has been hypothesized that hyperventilation disorders could be characterized by an abnormal ventilatory control leading to enhanced variability of resting ventilation. The variability of tidal volume (VT) often depicts a nonnormal distribution that can be described by the negative slope characterizing augmented breaths formed by the relationship between the probability density distribution of VT and VT on a log-log scale. The objectives of this study were to describe the variability of resting ventilation [coefficient of variation (CV) of VT and slope], the stability in respiratory control (loop, controller and plant gains characterizing ventilatory-chemoresponsiveness interactions) and the chaotic-like dynamics (embedding dimension, Kappa values characterizing complexity) of resting ventilation in patients with a well-defined dysfunctional breathing pattern characterized by air hunger and constantly decreased PaCO2 during a cardiopulmonary exercise test. Compared with 14 healthy subjects with similar anthropometrics, 23 patients with hyperventilation were characterized by increased variability of resting tidal ventilation (CV of VT median [interquartile]: 26% [19-35] vs. 36% [28–48], P = 0.020; slope: −6.63 [−7.65; −5.36] vs. −3.88 [−5.91; −2.66], P = 0.004) that was not related to increased chemical drive (loop gain: 0.051 [0.039–0.221] vs. 0.044 [0.012–0.087], P = 0.149) but that was related to an increased ventilatory complexity (Kappa values, P < 0.05). Plant gain was decreased in patients and correlated with complexity (with Kappa 5 − degree 5: Rho = −0.48, P = 0.006). In conclusion, well-defined patients suffering from hyperventilation disorder are characterized by increased variability of their resting ventilation due to increased ventilatory complexity with stable ventilatory-chemoresponsiveness interactions.
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Affiliation(s)
- Plamen Bokov
- AP-HP, Hôpital Européen Georges Pompidou, Service de Physiologie, Clinique de la Dyspnée, Paris, and Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Marie-Noëlle Fiamma
- Sorbonne Universités, UPMC Université Paris 06, UMR_S 1158, Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
| | - Brigitte Chevalier-Bidaud
- AP-HP, Hôpital Européen Georges Pompidou, Unité d'Épidémiologie et de Recherche Clinique, Paris, France
| | - Cécile Chenivesse
- Sorbonne Universités, UPMC Université Paris 06, UMR_S 1158, Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale, Paris, France
| | - Christian Straus
- Sorbonne Universités, UPMC Université Paris 06, UMR_S 1158, Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service d'Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée, Paris, France
| | - Thomas Similowski
- Sorbonne Universités, UPMC Université Paris 06, UMR_S 1158, Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale, Paris, France
| | - Christophe Delclaux
- AP-HP, Hôpital Européen Georges Pompidou, Service de Physiologie, Clinique de la Dyspnée, Paris, and Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
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18
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Ranohavimparany A, Bautin N, Fiamma MN, Similowski T, Straus C. Source of ventilatory complexity in the postmetamorphic tadpole brainstem, Pelophylax ridibundus: A pharmacological study. Respir Physiol Neurobiol 2016; 224:27-36. [DOI: 10.1016/j.resp.2014.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 10/22/2014] [Accepted: 11/06/2014] [Indexed: 10/24/2022]
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19
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Di Mussi R, Spadaro S, Mirabella L, Volta CA, Serio G, Staffieri F, Dambrosio M, Cinnella G, Bruno F, Grasso S. Impact of prolonged assisted ventilation on diaphragmatic efficiency: NAVA versus PSV. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2016; 20:1. [PMID: 26728475 PMCID: PMC4700777 DOI: 10.1186/s13054-015-1178-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/19/2015] [Indexed: 12/16/2022]
Abstract
Background Prolonged controlled mechanical ventilation depresses diaphragmatic efficiency. Assisted modes of ventilation should improve it. We assessed the impact of pressure support ventilation versus neurally adjusted ventilator assist on diaphragmatic efficiency. Method Patients previously ventilated with controlled mechanical ventilation for 72 hours or more were randomized to be ventilated for 48 hours with pressure support ventilation (n =12) or neurally adjusted ventilatory assist (n = 13). Neuro-ventilatory efficiency (tidal volume/diaphragmatic electrical activity) and neuro-mechanical efficiency (pressure generated against the occluded airways/diaphragmatic electrical activity) were measured during three spontaneous breathing trials (0, 24 and 48 hours). Breathing pattern, diaphragmatic electrical activity and pressure time product of the diaphragm were assessed every 4 hours. Results In patients randomized to neurally adjusted ventilator assist, neuro-ventilatory efficiency increased from 27 ± 19 ml/μV at baseline to 62 ± 30 ml/μV at 48 hours (p <0.0001) and neuro-mechanical efficiency increased from 1 ± 0.6 to 2.6 ± 1.1 cmH2O/μV (p = 0.033). In patients randomized to pressure support ventilation, these did not change. Electrical activity of the diaphragm, neural inspiratory time, pressure time product of the diaphragm and variability of the breathing pattern were significantly higher in patients ventilated with neurally adjusted ventilatory assist. The asynchrony index was 9.48 [6.38– 21.73] in patients ventilated with pressure support ventilation and 5.39 [3.78– 8.36] in patients ventilated with neurally adjusted ventilatory assist (p = 0.04). Conclusion After prolonged controlled mechanical ventilation, neurally adjusted ventilator assist improves diaphragm efficiency whereas pressure support ventilation does not. Trial registration ClinicalTrials.gov study registration: NCT0247317, 06/11/2015.
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Affiliation(s)
- Rosa Di Mussi
- Dipartimento dell'Emergenza e Trapianti d'Organo (DETO), Sezione di Anestesiologia e Rianimazione, Università degli Studi di Bari "Aldo Moro", Piazza Giulio Cesare 11, Bari, Italy.
| | - Savino Spadaro
- Dipartimento di Morfologia, Chirurgia e Medicina Sperimentale, Sezione di Anestesiologia e Terapia Intensiva Universitaria, Università degli studi di Ferrara, Ferrara, Italy.
| | - Lucia Mirabella
- Dipartimento di Anestesia e Rianimazione, Università di Foggia, Foggia, Italy.
| | - Carlo Alberto Volta
- Dipartimento di Morfologia, Chirurgia e Medicina Sperimentale, Sezione di Anestesiologia e Terapia Intensiva Universitaria, Università degli studi di Ferrara, Ferrara, Italy.
| | - Gabriella Serio
- Dipartimento di Scienze Biomediche ed Oncologia Umana, Cattedra di Statistica Medica, Università degli Studi Aldo Moro, Bari, Italy.
| | - Francesco Staffieri
- Dipartimento dell'Emergenza e Trapianti d'Organo (DETO), Sezione di Chirurgia Veterinaria, Università degli Studi di Bari "Aldo Moro", Bari, Italy.
| | - Michele Dambrosio
- Dipartimento di Anestesia e Rianimazione, Università di Foggia, Foggia, Italy.
| | - Gilda Cinnella
- Dipartimento di Anestesia e Rianimazione, Università di Foggia, Foggia, Italy.
| | - Francesco Bruno
- Dipartimento dell'Emergenza e Trapianti d'Organo (DETO), Sezione di Anestesiologia e Rianimazione, Università degli Studi di Bari "Aldo Moro", Piazza Giulio Cesare 11, Bari, Italy.
| | - Salvatore Grasso
- Dipartimento dell'Emergenza e Trapianti d'Organo (DETO), Sezione di Anestesiologia e Rianimazione, Università degli Studi di Bari "Aldo Moro", Piazza Giulio Cesare 11, Bari, Italy.
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20
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Corcoran AE, Richerson GB, Harris MB. Functional link between the hypocretin and serotonin systems in the neural control of breathing and central chemosensitivity. J Neurophysiol 2015; 114:381-9. [PMID: 25878157 DOI: 10.1152/jn.00870.2013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 04/09/2015] [Indexed: 11/22/2022] Open
Abstract
Serotonin (5-HT)-synthesizing neurons of the medullary raphe are putative central chemoreceptors, proposed to be one of potentially multiple brain stem chemosensitive cell types and loci interacting to produce the respiratory chemoreflex. Hypocretin-synthesizing neurons of the lateral hypothalamus are important contributors to arousal state, thermoregulation, and feeding behavior and are also reportedly involved in the hypercapnic ventilatory response. Recently, a functional interaction was found between the hypocretin system and 5-HT neurons of the dorsal raphe. The validity and potential significance of hypocretin modulation of medullary raphe 5-HT neurons, however, is unknown. As such, the purpose of this study was to explore functional interactions between the hypocretin system and 5-HT system of the medullary raphe on baseline respiratory output and central chemosensitivity. To explore such interactions, we used the neonatal in vitro medullary slice preparation derived from wild-type (WT) mice (normal 5-HT function) and a knockout strain lacking all central 5-HT neurons (Lmx1b(f/f/p) mice). We examined effects of acidosis, hypocretin-1, a hypocretin receptor antagonist (SB-408124), and the effect of the antagonist on the response to acidosis. We confirmed the critical role of 5-HT neurons in central chemosensitivity given that the increased hypoglossal burst frequency with acidosis, characteristic of WT mice, was absent in preparations derived from Lmx1b(f/f/p) mice. We also found that hypocretin facilitated baseline neural ventilatory output in part through 5-HT neurons. Although the impact of hypocretin on 5-HT neuronal sensitivity to acidosis is still unclear, hypocretins did appear to mediate the burst duration response to acidosis via serotonergic mechanisms.
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Affiliation(s)
- Andrea E Corcoran
- Department of Biology and Wildlife, and Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska; Departments of Neurology and Cellular & Molecular Physiology, Yale University, New Haven, Connecticut; Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire;
| | - George B Richerson
- Departments of Neurology and Cellular & Molecular Physiology, Yale University, New Haven, Connecticut; Veteran's Affairs Medical Center, West Haven, Connecticut; and Departments of Neurology and Molecular Physiology & Biophysics, University of Iowa, Iowa City, Iowa
| | - Michael B Harris
- Department of Biology and Wildlife, and Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
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Schmidt M, Kindler F, Cecchini J, Poitou T, Morawiec E, Persichini R, Similowski T, Demoule A. Neurally adjusted ventilatory assist and proportional assist ventilation both improve patient-ventilator interaction. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:56. [PMID: 25879592 PMCID: PMC4355459 DOI: 10.1186/s13054-015-0763-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 01/22/2015] [Indexed: 12/02/2022]
Abstract
Introduction The objective was to compare the impact of three assistance levels of different modes of mechanical ventilation; neurally adjusted ventilatory assist (NAVA), proportional assist ventilation (PAV), and pressure support ventilation (PSV) on major features of patient-ventilator interaction. Methods PSV, NAVA, and PAV were set to obtain a tidal volume (VT) of 6 to 8 ml/kg (PSV100, NAVA100, and PAV100) in 16 intubated patients. Assistance was further decreased by 50% (PSV50, NAVA50, and PAV50) and then increased by 50% (PSV150, NAVA150, and PAV150) with all modes. The three modes were randomly applied. Airway flow and pressure, electrical activity of the diaphragm (EAdi), and blood gases were measured. VT, peak EAdi, coefficient of variation of VT and EAdi, and the prevalence of the main patient-ventilator asynchronies were calculated. Results PAV and NAVA prevented the increase of VT with high levels of assistance (median 7.4 (interquartile range (IQR) 5.7 to 10.1) ml/kg and 7.4 (IQR, 5.9 to 10.5) ml/kg with PAV150 and NAVA150 versus 10.9 (IQR, 8.9 to 12.0) ml/kg with PSV150, P <0.05). EAdi was higher with PAV than with PSV at level100 and level150. The coefficient of variation of VT was higher with NAVA and PAV (19 (IQR, 14 to 31)% and 21 (IQR 16 to 29)% with NAVA100 and PAV100 versus 13 (IQR 11 to 18)% with PSV100, P <0.05). The prevalence of ineffective triggering was lower with PAV and NAVA than with PSV (P <0.05), but the prevalence of double triggering was higher with NAVA than with PAV and PSV (P <0.05). Conclusions PAV and NAVA both prevent overdistention, improve neuromechanical coupling, restore the variability of the breathing pattern, and decrease patient-ventilator asynchrony in fairly similar ways compared with PSV. Further studies are needed to evaluate the possible clinical benefits of NAVA and PAV on clinical outcomes. Trial registration Clinicaltrials.gov NCT02056093. Registered 18 December 2013. Electronic supplementary material The online version of this article (doi:10.1186/s13054-015-0763-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Matthieu Schmidt
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,INSERM, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), F-75013, Paris, France. .,Service de Pneumologie et Réanimation Médicale, Groupe Hospitalier Pitié-Salpêtrière, 47-83 boulevard de l'Hôpital, 75651, Paris, Cedex 13, France.
| | - Felix Kindler
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), F-75013, Paris, France.
| | - Jérôme Cecchini
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,INSERM, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France.
| | - Tymothée Poitou
- Université Pierre et Marie Curie-CNRS-INSERM, ICM, Equipe Neurologie et Thérapeutique Expérimentale, Hôpital de la Salpêtrière, Paris, France.
| | - Elise Morawiec
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,INSERM, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), F-75013, Paris, France.
| | - Romain Persichini
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), F-75013, Paris, France.
| | - Thomas Similowski
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,INSERM, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), F-75013, Paris, France.
| | - Alexandre Demoule
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,INSERM, UMR_S 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75005, Paris, France. .,AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), F-75013, Paris, France. .,U974, Institut National de la Santé et de la Recherche médicale, Paris, France.
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Jerath R, Crawford MW, Barnes VA, Harden K. Widespread depolarization during expiration: A source of respiratory drive? Med Hypotheses 2015; 84:31-7. [DOI: 10.1016/j.mehy.2014.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 10/23/2014] [Accepted: 11/08/2014] [Indexed: 12/21/2022]
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Schmidt M, Cecchini J, Kindler F, Similowski T, Demoule A. Variabilité ventilatoire et assistance ventilatoire en réanimation. MEDECINE INTENSIVE REANIMATION 2014. [DOI: 10.1007/s13546-014-0843-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Dames KK, Lopes AJ, de Melo PL. Airflow pattern complexity during resting breathing in patients with COPD: effect of airway obstruction. Respir Physiol Neurobiol 2013; 192:39-47. [PMID: 24334010 DOI: 10.1016/j.resp.2013.12.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/29/2013] [Accepted: 12/03/2013] [Indexed: 12/01/2022]
Abstract
We investigated the influence of airway obstruction in the complexity of the airflow pattern in COPD and its use as a marker of disease activity. The sample entropy (SampEnV') and the variability (SDV') of the airflow pattern were measured in a group of 88 subjects with various levels of airway obstruction. Airway obstruction resulted in a reduction in the SampEnV' (p<0.0001) that was significantly correlated with spirometric indices of airway obstruction (R=0.50, p<0.001). The early adverse effects in mild airway obstruction were detected by the SampEnV' with an accuracy of 84%. SDV' increased with airway obstruction (p<0.002). We conclude that (1) the airflow patterns in COPD exhibit reduced complexity compared with healthy subjects; (2) this reduction in complexity is proportional to airway obstruction; and (3) the evaluation of SampEnV' may provide novel respiratory biomarkers suitable to facilitate the diagnosis of respiratory abnormalities in COPD.
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Affiliation(s)
- Karla Kristine Dames
- Biomedical Instrumentation Laboratory, Institute of Biology and Faculty of Engineering, State University of Rio de Janeiro, Brazil
| | - Agnaldo José Lopes
- Pulmonary Function Laboratory, Faculty of Medical Sciences, State University of Rio de Janeiro, Brazil
| | - Pedro Lopes de Melo
- Biomedical Instrumentation Laboratory, Institute of Biology and Faculty of Engineering, State University of Rio de Janeiro, Brazil; Clinical and Experimental Research Laboratory in Vascular Biology, Institute of Biology, State University of Rio de Janeiro, Brazil.
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Tobin MJ, Laghi F, Jubran A. Ventilatory failure, ventilator support, and ventilator weaning. Compr Physiol 2013; 2:2871-921. [PMID: 23720268 DOI: 10.1002/cphy.c110030] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The development of acute ventilatory failure represents an inability of the respiratory control system to maintain a level of respiratory motor output to cope with the metabolic demands of the body. The level of respiratory motor output is also the main determinant of the degree of respiratory distress experienced by such patients. As ventilatory failure progresses and patient distress increases, mechanical ventilation is instituted to help the respiratory muscles cope with the heightened workload. While a patient is connected to a ventilator, a physician's ability to align the rhythm of the machine with the rhythm of the patient's respiratory centers becomes the primary determinant of the level of rest accorded to the respiratory muscles. Problems of alignment are manifested as failure to trigger, double triggering, an inflationary gas-flow that fails to match inspiratory demands, and an inflation phase that persists after a patient's respiratory centers have switched to expiration. With recovery from disorders that precipitated the initial bout of acute ventilatory failure, attempts are made to discontinue the ventilator (weaning). About 20% of weaning attempts fail, ultimately, because the respiratory controller is unable to sustain ventilation and this failure is signaled by development of rapid shallow breathing. Substantial advances in the medical management of acute ventilatory failure that requires ventilator assistance are most likely to result from research yielding novel insights into the operation of the respiratory control system.
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Affiliation(s)
- Martin J Tobin
- Division of Pulmonary and Critical Care Medicine, Edward Hines Jr. Veterans Affairs Hospital and Loyola University of Chicago Stritch School of Medicine, Hines, Illinois, USA.
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Seppä VP, Pelkonen AS, Kotaniemi-Syrjänen A, Mäkelä MJ, Viik J, Malmberg LP. Tidal breathing flow measurement in awake young children by using impedance pneumography. J Appl Physiol (1985) 2013; 115:1725-31. [PMID: 24092693 DOI: 10.1152/japplphysiol.00657.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Characteristics of tidal breathing (TB) relate to lung function and may be assessed even in young children. Thus far, the accuracy of impedance pneumography (IP) in recording TB flows in young children with or without bronchial obstruction has not been evaluated. The aim of this study was to evaluate the agreement between IP and direct flow measurement with pneumotachograph (PNT) in assessing TB flow and flow-derived indices relating to airway obstruction in young children. Tidal flow was recorded for 1 min simultaneously with IP and PNT during different phases of a bronchial challenge test with methacholine in 21 wheezy children aged 3 to 7 years. The agreement of IP with PNT was found to be excellent in direct flow signal comparison, the mean deviation from linearity ranging from 2.4 to 3.1% of tidal peak inspiratory flow. Methacholine-induced bronchoconstriction or consecutive bronchodilation induced only minor changes in the agreement. Between IP and PNT, the obstruction-related tidal flow indices were equally repeatable, and agreement was found to be high, with intraclass correlation coefficients for T PTEF/T E, V PTEF/V E, and parameter S being 0.94, 0.91, and 0.68, respectively. Methacholine-induced changes in tidal flow indices showed significant associations with changes in mechanical impedance of the respiratory system assessed by the oscillometric technique, with the highest correlation found in V PTEF/V E (r = -0.54; P < 0.005 and r = -0.55; P < 0.005 by using IP or PNT, respectively). The results indicate that IP can be considered as a valid method for recording tidal airflow profiles in young children with wheezing disorders.
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Affiliation(s)
- Ville-Pekka Seppä
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
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Hess A, Yu L, Klein I, De Mazancourt M, Jebrak G, Mal H, Brugière O, Fournier M, Courbage M, Dauriat G, Schouman-Clayes E, Clerici C, Mangin L. Neural mechanisms underlying breathing complexity. PLoS One 2013; 8:e75740. [PMID: 24098396 PMCID: PMC3789752 DOI: 10.1371/journal.pone.0075740] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 08/20/2013] [Indexed: 01/22/2023] Open
Abstract
Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD). COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI), we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL) medulla (pre-Bötzinger complex) and the caudal VL pons (parafacial group). fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in neurons can contribute to chaos in airflow and reproduces key experimental fMRI findings.
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Affiliation(s)
- Agathe Hess
- Laboratoire Matière et Systèmes complexes, UMR 7057, CNRS, Université Paris 7, Paris, France
- Service de Radiologie, APHP, Hôpital Bichat-Claude Bernard, Paris, France
| | - Lianchun Yu
- Laboratoire Matière et Systèmes complexes, UMR 7057, CNRS, Université Paris 7, Paris, France
- Institute of Theoretical Physics, Lanzhou University, Lanzhou, China
| | - Isabelle Klein
- Service de Radiologie, APHP, Hôpital Bichat-Claude Bernard, Paris, France
- Unité Inserm 698, Université Paris 7, Paris, France
| | - Marine De Mazancourt
- Laboratoire Matière et Systèmes complexes, UMR 7057, CNRS, Université Paris 7, Paris, France
- Ecole Normale Supérieure, Paris, France
| | - Gilles Jebrak
- Service de Pneumologie B, APHP, Hôpital Bichat-Claude Bernard, Paris, France
| | - Hervé Mal
- Service de Pneumologie B, APHP, Hôpital Bichat-Claude Bernard, Paris, France
| | - Olivier Brugière
- Service de Pneumologie B, APHP, Hôpital Bichat-Claude Bernard, Paris, France
| | - Michel Fournier
- Service de Pneumologie B, APHP, Hôpital Bichat-Claude Bernard, Paris, France
| | - Maurice Courbage
- Laboratoire Matière et Systèmes complexes, UMR 7057, CNRS, Université Paris 7, Paris, France
| | - Gaelle Dauriat
- Service de Pneumologie B, APHP, Hôpital Bichat-Claude Bernard, Paris, France
| | | | - Christine Clerici
- Département de Physiologie-Explorations fonctionnelles, APHP, Hôpital Bichat-Claude Bernard, Paris, France
- Unité Inserm 700, Université Paris 7, Paris, France
| | - Laurence Mangin
- Laboratoire Matière et Systèmes complexes, UMR 7057, CNRS, Université Paris 7, Paris, France
- Département de Physiologie-Explorations fonctionnelles, APHP, Hôpital Bichat-Claude Bernard, Paris, France
- Centre d’Investigation Clinique APHP, Hôpital Bichat, Paris, France
- * E-mail:
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Control of ventilation in COPD and lung injury. Respir Physiol Neurobiol 2013; 189:371-6. [PMID: 23856486 DOI: 10.1016/j.resp.2013.07.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Revised: 06/27/2013] [Accepted: 07/04/2013] [Indexed: 11/23/2022]
Abstract
Breathing occurs in single breaths and in patterns which are altered by the onset, progression and resolution of respiratory diseases. Through modulations of rate, depth, and patterning of breathing, the ventilatory control system maintains numerous critical variables within their homeostatic ranges. A dynamic respiratory control system is critical to successful adaptation in the face of progressive pulmonary pathology. The objective of this review, is to illustrate functional changes and compensatory mechanisms which occur with the onset and progression of acute and chronic lung disease. Chronic obstructive pulmonary disease (COPD) will be considered as a model of a slowly progressive pulmonary process, where destruction of lung parenchyma and airway obstruction leads to hypoxemia and hypercapnia. Over time, adaptations of the respiratory control system to this disease include changes in the intrinsic properties of respiratory muscles, chemoreceptor signaling, and central respiratory drive which increase motor output to the respiratory muscles. In contrast, acute respiratory distress syndrome (ARDS) is an exemplar of an acute pulmonary process. The result of severe lung injury, ARDS is characterized by lung infiltrates, rapidly progressive hypoxemic respiratory failure, and possible progression to pulmonary fibrosis. Changes in breathing patterns result from these functional changes, as well as altered processing of afferent feedback by the central controller, possibly influenced by brainstem inflammation. Taken together, these disease models highlight the plasticity of the respiratory control system in response to the development and progression of lung disease.
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Terzi N, Piquilloud L, Rozé H, Mercat A, Lofaso F, Delisle S, Jolliet P, Sottiaux T, Tassaux D, Roesler J, Demoule A, Jaber S, Mancebo J, Brochard L, Richard JCM. Clinical review: Update on neurally adjusted ventilatory assist--report of a round-table conference. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2012; 16:225. [PMID: 22715815 PMCID: PMC3580602 DOI: 10.1186/cc11297] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Conventional mechanical ventilators rely on pneumatic pressure and flow sensors and controllers to detect breaths. New modes of mechanical ventilation have been developed to better match the assistance delivered by the ventilator to the patient's needs. Among these modes, neurally adjusted ventilatory assist (NAVA) delivers a pressure that is directly proportional to the integral of the electrical activity of the diaphragm recorded continuously through an esophageal probe. In clinical settings, NAVA has been chiefly compared with pressure-support ventilation, one of the most popular modes used during the weaning phase, which delivers a constant pressure from breath to breath. Comparisons with proportional-assist ventilation, which has numerous similarities, are lacking. Because of the constant level of assistance, pressure-support ventilation reduces the natural variability of the breathing pattern and can be associated with asynchrony and/or overinflation. The ability of NAVA to circumvent these limitations has been addressed in clinical studies and is discussed in this report. Although the underlying concept is fascinating, several important questions regarding the clinical applications of NAVA remain unanswered. Among these questions, determining the optimal NAVA settings according to the patient's ventilatory needs and/or acceptable level of work of breathing is a key issue. In this report, based on an investigator-initiated round table, we review the most recent literature on this topic and discuss the theoretical advantages and disadvantages of NAVA compared with other modes, as well as the risks and limitations of NAVA.
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Lee J, Nemati S, Silva I, Edwards BA, Butler JP, Malhotra A. Transfer entropy estimation and directional coupling change detection in biomedical time series. Biomed Eng Online 2012; 11:19. [PMID: 22500692 PMCID: PMC3403001 DOI: 10.1186/1475-925x-11-19] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 04/13/2012] [Indexed: 11/28/2022] Open
Abstract
Background The detection of change in magnitude of directional coupling between two non-linear time series is a common subject of interest in the biomedical domain, including studies involving the respiratory chemoreflex system. Although transfer entropy is a useful tool in this avenue, no study to date has investigated how different transfer entropy estimation methods perform in typical biomedical applications featuring small sample size and presence of outliers. Methods With respect to detection of increased coupling strength, we compared three transfer entropy estimation techniques using both simulated time series and respiratory recordings from lambs. The following estimation methods were analyzed: fixed-binning with ranking, kernel density estimation (KDE), and the Darbellay-Vajda (D-V) adaptive partitioning algorithm extended to three dimensions. In the simulated experiment, sample size was varied from 50 to 200, while coupling strength was increased. In order to introduce outliers, the heavy-tailed Laplace distribution was utilized. In the lamb experiment, the objective was to detect increased respiratory-related chemosensitivity to O2 and CO2 induced by a drug, domperidone. Specifically, the separate influence of end-tidal PO2 and PCO2 on minute ventilation (V˙E) before and after administration of domperidone was analyzed. Results In the simulation, KDE detected increased coupling strength at the lowest SNR among the three methods. In the lamb experiment, D-V partitioning resulted in the statistically strongest increase in transfer entropy post-domperidone for PO2→V˙E. In addition, D-V partitioning was the only method that could detect an increase in transfer entropy for PCO2→V˙E, in agreement with experimental findings. Conclusions Transfer entropy is capable of detecting directional coupling changes in non-linear biomedical time series analysis featuring a small number of observations and presence of outliers. The results of this study suggest that fixed-binning, even with ranking, is too primitive, and although there is no clear winner between KDE and D-V partitioning, the reader should note that KDE requires more computational time and extensive parameter selection than D-V partitioning. We hope this study provides a guideline for selection of an appropriate transfer entropy estimation method.
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Affiliation(s)
- Joon Lee
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA.
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Comparisons of predictive performance of breathing pattern variability measured during T-piece, automatic tube compensation, and pressure support ventilation for weaning intensive care unit patients from mechanical ventilation. Crit Care Med 2011; 39:2253-62. [PMID: 21666447 DOI: 10.1097/ccm.0b013e31822279ed] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the influence of different ventilatory supports on the predictive performance of breathing pattern variability for extubation outcomes in intensive care unit patients. DESIGN AND SETTING A prospective measurement of retrospectively analyzed breathing pattern variability in a medical center. PATIENTS Sixty-eight consecutive and ready-for-weaning patients were divided into success (n=45) and failure (n=23) groups based on their extubation outcomes. MEASUREMENTS Breath-to-breath analyses of peak inspiratory flow, total breath duration, tidal volume, and rapid shallow breathing index were performed for three 30-min periods while patients randomly received T-piece, 100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure, and 5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure trials. Coefficient of variations and data dispersion (standard descriptor values SD1 and SD2 of the Poincaré plot) were analyzed to serve as breathing pattern variability indices. MAIN RESULTS Under all three trials, breathing pattern variability in extubation failure patients was smaller than in extubation success patients. Compared to the T-piece trial, 100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure and 5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure decreased the ability of certain breathing pattern variability indices to discriminate extubation success from extubation failure. The areas under the receiver operating characteristic curve of these breathing pattern variability indices were: T-piece (0.73-0.87)>100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure (0.60-0.79)>5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure (0.53-0.76). Analysis of the classification and regression tree indicated that during the T-piece trial, a SD1 of peak inspiratory flow>3.36 L/min defined a group including all extubation success patients. Conversely, the combination of a SD1 of peak inspiratory flow ≤3.36 L/min and a coefficient of variations of rapid shallow breathing index ≤0.23 defined a group of all extubation failure patients. The decision strategies using SD1 of peak inspiratory flow and coefficient of variations of rapid shallow breathing index measured during 100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure and 5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure trials achieved a less clear separation of extubation failure from extubation success. CONCLUSIONS Since 100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure and 5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure reduce the predictive performance of breathing pattern variability, breathing pattern variability measurement during the T-piece trial is the best choice for predicting extubation outcome in intensive care unit patients patients.
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Jacono FJ, Mayer CA, Hsieh YH, Wilson CG, Dick TE. Lung and brainstem cytokine levels are associated with breathing pattern changes in a rodent model of acute lung injury. Respir Physiol Neurobiol 2011; 178:429-38. [PMID: 21569869 PMCID: PMC3170447 DOI: 10.1016/j.resp.2011.04.022] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 04/22/2011] [Accepted: 04/27/2011] [Indexed: 02/07/2023]
Abstract
Acute lung injury evokes a pulmonary inflammatory response and changes in the breathing pattern. The inflammatory response has a centrally mediated component which depends on the vagi. We hypothesize that the central inflammatory response, complimentary to the pulmonary inflammatory response, is expressed in the nuclei tractus solitarii (nTS) and that the expression of cytokines in the nTS is associated with breathing pattern changes. Adult, male Sprague-Dawley rats (n=12) received intratracheal instillation of either bleomycin (3units in 120μl of saline) or saline (120μl). Respiratory pattern changed by 24h. At 48h, bronchoalveolar lavage fluid and lung tissue had increased IL-1β and TNF-α levels, but not IL-6. No changes in these cytokines were noted in serum. Immunocytochemical analysis of the brainstem indicated increased expression of IL-1β in the nTS commissural subnucleus that was localized to neurons. We conclude that breathing pattern changes in acute lung injury were associated with increased levels of IL-1β in brainstem areas which integrate cardio-respiratory sensory input.
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Affiliation(s)
- Frank J Jacono
- Division of Pulmonary, Critical Care and Sleep Medicine, CWRU School of Medicine and University Hospitals Case Medical Center, United States.
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What can variability and complexity tell us about breathing control in humans? J Crit Care 2011. [DOI: 10.1016/j.jcrc.2011.02.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Straus C, Samara Z, Fiamma MN, Bautin N, Ranohavimparany A, Le Coz P, Golmard JL, Darré P, Zelter M, Poon CS, Similowski T. Effects of maturation and acidosis on the chaos-like complexity of the neural respiratory output in the isolated brainstem of the tadpole, Rana esculenta. Am J Physiol Regul Integr Comp Physiol 2011; 300:R1163-74. [PMID: 21325645 PMCID: PMC3094042 DOI: 10.1152/ajpregu.00710.2009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 02/14/2011] [Indexed: 11/22/2022]
Abstract
Human ventilation at rest exhibits mathematical chaos-like complexity that can be described as long-term unpredictability mediated (in whole or in part) by some low-dimensional nonlinear deterministic process. Although various physiological and pathological situations can affect respiratory complexity, the underlying mechanisms remain incompletely elucidated. If such chaos-like complexity is an intrinsic property of central respiratory generators, it should appear or increase when these structures mature or are stimulated. To test this hypothesis, we employed the isolated tadpole brainstem model [Rana (Pelophylax) esculenta] and recorded the neural respiratory output (buccal and lung rhythms) of pre- (n = 8) and postmetamorphic tadpoles (n = 8), at physiologic (7.8) and acidic pH (7.4). We analyzed the root mean square of the cranial nerve V or VII neurograms. Development and acidosis had no effect on buccal period. Lung frequency increased with development (P < 0.0001). It also increased with acidosis, but in postmetamorphic tadpoles only (P < 0.05). The noise-titration technique evidenced low-dimensional nonlinearities in all the postmetamorphic brainstems, at both pH. Chaos-like complexity, assessed through the noise limit, increased from pH 7.8 to pH 7.4 (P < 0.01). In contrast, linear models best fitted the ventilatory rhythm in all but one of the premetamorphic preparations at pH 7.8 (P < 0.005 vs. postmetamorphic) and in four at pH 7.4 (not significant vs. postmetamorphic). Therefore, in a lower vertebrate model, the brainstem respiratory central rhythm generator accounts for ventilatory chaos-like complexity, especially in the postmetamorphic stage and at low pH. According to the ventilatory generators homology theory, this may also be the case in mammals.
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Affiliation(s)
- Christian Straus
- Service Central d'Explorations Fonctionnelles Respiratoires, Groupe Hospitalier Pitie-Salpetriere, 47-83 Boulevard de l'Hôpital, Paris Cedex 13, France
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Dhingra RR, Jacono FJ, Fishman M, Loparo KA, Rybak IA, Dick TE. Vagal-dependent nonlinear variability in the respiratory pattern of anesthetized, spontaneously breathing rats. J Appl Physiol (1985) 2011; 111:272-84. [PMID: 21527661 DOI: 10.1152/japplphysiol.91196.2008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Physiological rhythms, including respiration, exhibit endogenous variability associated with health, and deviations from this are associated with disease. Specific changes in the linear and nonlinear sources of breathing variability have not been investigated. In this study, we used information theory-based techniques, combined with surrogate data testing, to quantify and characterize the vagal-dependent nonlinear pattern variability in urethane-anesthetized, spontaneously breathing adult rats. Surrogate data sets preserved the amplitude distribution and linear correlations of the original data set, but nonlinear correlation structure in the data was removed. Differences in mutual information and sample entropy between original and surrogate data sets indicated the presence of deterministic nonlinear or stochastic non-Gaussian variability. With vagi intact (n = 11), the respiratory cycle exhibited significant nonlinear behavior in templates of points separated by time delays ranging from one sample to one cycle length. After vagotomy (n = 6), even though nonlinear variability was reduced significantly, nonlinear properties were still evident at various time delays. Nonlinear deterministic variability did not change further after subsequent bilateral microinjection of MK-801, an N-methyl-D-aspartate receptor antagonist, in the Kölliker-Fuse nuclei. Reversing the sequence (n = 5), blocking N-methyl-D-aspartate receptors bilaterally in the dorsolateral pons significantly decreased nonlinear variability in the respiratory pattern, even with the vagi intact, and subsequent vagotomy did not change nonlinear variability. Thus both vagal and dorsolateral pontine influences contribute to nonlinear respiratory pattern variability. Furthermore, breathing dynamics of the intact system are mutually dependent on vagal and pontine sources of nonlinear complexity. Understanding the structure and modulation of variability provides insight into disease effects on respiratory patterning.
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Affiliation(s)
- R R Dhingra
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH 44106, USA
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Roulin E, Freitas US, Letellier C. Working conditions for safe detection of nonlinearity and noise titration. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:046225. [PMID: 21599288 DOI: 10.1103/physreve.83.046225] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Indexed: 05/30/2023]
Abstract
Even if noise titration cannot be satisfactorily used to prove the presence of chaos, it can still be used to detect nonlinear component in dynamics. Nevertheless, since the technique have the use of nonlinear models for one-step-ahead predictions, it requires an acute choice of modeling parameters, i.e., the number of terms and the nonlinearity degree of the models. Based on illustrative examples, we propose conditions under which the method of noise titration can be reliably applied to characterize nonlinearity in the time series. It is thus possible to compare different time series and state which one is governed by the strongest nonlinearity. For instance, it is shown that, when there is a single nonlinear term in the equations describing the system, the variable on which it acts can be identified among the others.
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Affiliation(s)
- Elise Roulin
- CORIA UMR 6614, University of Rouen, BP. 12, F-76801 Saint-Etienne du Rouvray cedex, France
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37
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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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Papaioannou VE, Chouvarda IG, Maglaveras NK, Pneumatikos IA. Study of multiparameter respiratory pattern complexity in surgical critically ill patients during weaning trials. BMC PHYSIOLOGY 2011; 11:2. [PMID: 21255420 PMCID: PMC3031268 DOI: 10.1186/1472-6793-11-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 01/21/2011] [Indexed: 11/20/2022]
Abstract
Background Separation from mechanical ventilation is a difficult task, whereas conventional predictive indices have not been proven accurate enough, so far. A few studies have explored changes of breathing pattern variability for weaning outcome prediction, with conflicting results. In this study, we tried to assess respiratory complexity during weaning trials, using different non-linear methods derived from theory of complex systems, in a cohort of surgical critically ill patients. Results Thirty two patients were enrolled in the study. There were 22 who passed and 10 who failed a weaning trial. Tidal volume and mean inspiratory flow were analyzed for 10 minutes during two phases: 1. pressure support (PS) ventilation (15-20 cm H2O) and 2. weaning trials with PS: 5 cm H2O. Sample entropy (SampEn), detrended fluctuation analysis (DFA) exponent, fractal dimension (FD) and largest lyapunov exponents (LLE) of the two respiratory parameters were computed in all patients and during the two phases of PS. Weaning failure patients exhibited significantly decreased respiratory pattern complexity, reflected in reduced sample entropy and lyapunov exponents and increased DFA exponents of respiratory flow time series, compared to weaning success subjects (p < 0.001). In addition, their changes were opposite between the two phases of the weaning trials. A new model including rapid shallow breathing index (RSBI), its product with airway occlusion pressure at 0.1 sec (P0.1), SampEn and LLE predicted better weaning outcome compared with RSBI, P0.1 and RSBI* P0.1 (conventional model, R2 = 0.874 vs 0.643, p < 0.001). Areas under the curve were 0.916 vs 0.831, respectively (p < 0.05). Conclusions We suggest that complexity analysis of respiratory signals can assess inherent breathing pattern dynamics and has increased prognostic impact upon weaning outcome in surgical patients.
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Vlemincx E, Taelman J, Van Diest I, Van den Bergh O. Take a deep breath: the relief effect of spontaneous and instructed sighs. Physiol Behav 2010; 101:67-73. [PMID: 20417649 DOI: 10.1016/j.physbeh.2010.04.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 04/07/2010] [Accepted: 04/15/2010] [Indexed: 11/16/2022]
Abstract
Spontaneous sighing is related to subjective relief of negative emotional states. Whether this also applies to instructed sighing is not known. The present study aimed to investigate sEMG and respiratory variability (1) during recovery from mental stress with and without an instructed sigh; (2) before and after spontaneous sighs throughout the experiment. A spontaneous sigh was preceded by increasing sEMG and increasing random respiratory variability, and followed by decreasing sEMG and increased structured correlated respiratory variability. Following an instructed sigh, a smaller reduction in sEMG and an increase in random respiratory variability during recovery from mental stress were observed. Thus, a spontaneous sigh seemed to induce relief. An instructed sigh appeared to inhibit recovery from mental stress.
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Affiliation(s)
- Elke Vlemincx
- Research Group on Health Psychology, Department of Psychology, University of Leuven, Belgium.
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Papaioannou V, Dragoumanis C, Pneumatikos I. Biosignal analysis techniques for weaning outcome assessment. J Crit Care 2009; 25:39-46. [PMID: 19592203 DOI: 10.1016/j.jcrc.2009.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 04/14/2009] [Accepted: 04/28/2009] [Indexed: 11/18/2022]
Abstract
Discontinuation of mechanical ventilation in critically ill patients is a challenging task and involves a careful weighting of the benefits of early extubation and the risks of premature spontaneous breathing trial. Recently, apart from studying different physiological variables by means of descriptive statistical tests, breathing pattern variability analysis has been performed for the assessment of weaning readiness. A limited number of clinical studies implementing different weaning protocols in heterogeneous groups of patients and using a variable set of signal processing techniques have appeared in the critical care literature, with varying results. The purpose of this review article is 3-fold: (1) to describe the different signal processing techniques being implemented for the assessment of weaning readiness, (2) to provide insight into the pathophysiological mechanisms that may govern breath-to-breath variability/complexity in health and disease, and (3) to present results from the critical care literature derived from the application of biosignal analysis tools for the identification of possible weaning indices.
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Affiliation(s)
- Vasilios Papaioannou
- Department of Intensive Care Medicine, Democritus University of Thrace, Alexandroupolis Medical School, 68100 Dragana, Greece.
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41
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Thamrin C, Frey U. Complexity and respiratory growth: a developing story. J Appl Physiol (1985) 2009; 106:753-4. [DOI: 10.1152/japplphysiol.91588.2008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Busha BF, Hage E, Hofmann C. Gender and breathing route modulate cardio-respiratory variability in humans. Respir Physiol Neurobiol 2009; 166:87-94. [PMID: 19429524 DOI: 10.1016/j.resp.2009.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 02/15/2009] [Accepted: 02/16/2009] [Indexed: 01/26/2023]
Abstract
During spontaneous breathing, there is an intrinsic scaling of respiratory variability and a correlation between respiratory and heart rate variabilities. To identify the effect of breathing route on respiratory and heart rate variabilities, breath-to-breath interval (BBI) and heartbeat-to-heartbeat interval (RRI) were recorded from 12 female and 12 male adult subjects breathing through the nose or mouth. Temporal scaling within the BBI and RRI was quantified with detrended fluctuation analysis (DFA). We identified a significant gender-based breathing route interaction in the short-term scaling of BBI (p=0.007), a decrease in the short-term scaling of RRI during nose breathing (p=0.026), and a significant interdependence of short-term scaling of BBI and RRI in female subjects. We conclude that there is a gender-based differential effect of breathing route on the control of respiration and an increase in the random behavior of RRI associated with nasal breathing. These data also suggest the presence cardio-respiratory coupling of scaling behavior in female subjects.
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Affiliation(s)
- Brett F Busha
- Department of Electrical and Computer Engineering, The College of New Jersey, NJ 08628, United States.
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Mitsis GD, Governo RJM, Rogers R, Pattinson KTS. The effect of remifentanil on respiratory variability, evaluated with dynamic modeling. J Appl Physiol (1985) 2009; 106:1038-49. [PMID: 19196914 DOI: 10.1152/japplphysiol.90769.2008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Opioid drugs disrupt signaling in the brain stem respiratory network affecting respiratory rhythm. We evaluated the influence of a steady-state infusion of a model opioid, remifentanil, on respiratory variability during spontaneous respiration in a group of 11 healthy human volunteers. We used dynamic linear and nonlinear models to examine the effects of remifentanil on both directions of the ventilatory loop, i.e., on the influence of natural variations in end-tidal carbon dioxide (Pet(CO(2))) on ventilatory variability, which was assessed by tidal volume (Vt) and breath-to-breath ventilation (i.e., the ratio of tidal volume over total breath time Vt/Ttot), and vice versa. Breath-by-breath recordings of expired CO(2) and respiration were made during a target-controlled infusion of remifentanil for 15 min at estimated effect site (i.e., brain tissue) concentrations of 0, 0.7, 1.1, and 1.5 ng/ml, respectively. Remifentanil caused a profound increase in the duration of expiration. The obtained models revealed a decrease in the strength of the dynamic effect of Pet(CO(2)) variability on Vt (the "controller" part of the ventilatory loop) and a more pronounced increase in the effect of Vt variability on Pet(CO(2)) (the "plant" part of the loop). Nonlinear models explained these dynamic interrelationships better than linear models. Our approach allows detailed investigation of drug effects in the resting state at the systems level using noninvasive and minimally perturbing experimental protocols, which can closely represent real-life clinical situations.
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Affiliation(s)
- G D Mitsis
- Institute of Communications and Computer Systems, National Technical University of Athens, Athens, Greece.
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Mangin L, Clerici C, Similowski T, Poon CS. Chaotic dynamics of cardioventilatory coupling in humans: effects of ventilatory modes. Am J Physiol Regul Integr Comp Physiol 2009; 296:R1088-97. [PMID: 19193943 DOI: 10.1152/ajpregu.90862.2008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardioventilatory coupling (CVC), a transient temporal alignment between the heartbeat and inspiratory activity, has been studied in animals and humans mainly during anesthesia. The origin of the coupling remains uncertain, whether or not ventilation is a main determinant in the CVC process and whether the coupling exhibits chaotic behavior. In this frame, we studied sedative-free, mechanically ventilated patients experiencing rapid sequential changes in breathing control during ventilator weaning during a switch from a machine-controlled assistance mode [assist-controlled ventilation (ACV)] to a patient-driven mode [inspiratory pressure support (IPS) and unsupported spontaneous breathing (USB)]. Time series were computed as R to start inspiration (RI) and R to the start of expiration (RE). Chaos was characterized with the noise titration method (noise limit), largest Lyapunov exponent (LLE) and correlation dimension (CD). All the RI and RE time series exhibit chaotic behavior. Specific coupling patterns were displayed in each ventilatory mode, and these patterns exhibited different linear and chaotic dynamics. When switching from ACV to IPS, partial inspiratory loading decreases the noise limit value, the LLE, and the correlation dimension of the RI and RE time series in parallel, whereas decreasing intrathoracic pressure from IPS to USB has the opposite effect. Coupling with expiration exhibits higher complexity than coupling with inspiration during mechanical ventilation either during ACV or IPS, probably due to active expiration. Only 33% of the cardiac time series (RR interval) exhibit complexity either during ACV, IPS, or USB making the contribution of the cardiac signal to the chaotic feature of the coupling minimal. We conclude that 1) CVC in unsedated humans exhibits a complex dynamic that can be chaotic, and 2) ventilatory mode has major effects on the linear and chaotic features of the coupling. Taken together these findings reinforce the role of ventilation in the CVC process.
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Affiliation(s)
- Laurence Mangin
- Hôpital Bichat-Claude Bernard, Service de Physiologie, Paris, France.
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Hypercapnia in late-phase ALI/ARDS: providing spontaneous breathing using pumpless extracorporeal lung assist. Intensive Care Med 2009; 35:1100-5. [DOI: 10.1007/s00134-009-1426-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 01/10/2009] [Indexed: 10/21/2022]
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Samara Z, Raux M, Fiamma MN, Gharbi A, Gottfried SB, Poon CS, Similowski T, Straus C. Effects of inspiratory loading on the chaotic dynamics of ventilatory flow in humans. Respir Physiol Neurobiol 2008; 165:82-9. [PMID: 19013545 DOI: 10.1016/j.resp.2008.10.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 09/25/2008] [Accepted: 10/16/2008] [Indexed: 10/21/2022]
Abstract
Human ventilation at rest exhibits complexity and chaos. The aim of this study was to determine whether suprapontine interferences with the automatic breathing control could contribute to ventilatory chaos. We conducted a post hoc analysis of a previous study performed in awake volunteers exhibiting cortical pre-motor potentials during inspiratory loading. In eight subjects, flow was recorded at rest, while breathing against inspiratory threshold loads (median 21.5 cm H(2)O) and resistive loads (50 cm H(2)Ol(-1)s(-1)) loads, and while inhaling 7% CO(2)-93% O(2). Chaos was identified through noise titration (noise limit, NL) and the sensitivity to initial conditions was assessed through the largest Lyapunov exponent (LLE). Breath-by-breath variability was evaluated using the coefficient of variation of several ventilatory variables. Chaos was consistently present in ventilatory flow recordings, but mechanical loading did not alter NL, LLE, or variability. In contrast, CO(2) altered chaos and reduced variability. In conclusion, inspiratory loading - and any resultant respiratory-related cortical activity - were not associated with changes in ventilatory chaos in this study, arguing against suprapontine contributions to ventilatory complexity.
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Affiliation(s)
- Ziyad Samara
- UPMC Univ Paris 06, EA 2397, F-75013 Paris, France
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Robbins PA. Commentaries on Viewpoint: Emergent phenomena and the secrets of life. J Appl Physiol (1985) 2008; 104:1850; author reply 1851. [DOI: 10.1152/japplphysiol.zdg-7945-vpcomm.2008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Mangin L, Fiamma MN, Straus C, Derenne JP, Zelter M, Clerici C, Similowski T. Source of human ventilatory chaos: lessons from switching controlled mechanical ventilation to inspiratory pressure support in critically ill patients. Respir Physiol Neurobiol 2008; 161:189-96. [PMID: 18387347 DOI: 10.1016/j.resp.2008.02.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Revised: 01/30/2008] [Accepted: 02/08/2008] [Indexed: 11/15/2022]
Abstract
Ventilatory flow measured at the airway opening in humans exhibits a complex dynamics that has the features of chaos. Currently available data point to a neural origin of this feature, but the role of respiratory mechanics has not been specifically assessed. In this aim, we studied 17 critically ill mechanically ventilated patients during a switch form an entirely machine-controlled assistance mode (assist-controlled ventilation ACV) to a patient-driven mode (inspiratory pressure support IPS). Breath-by-breath respiratory variability was assessed with the coefficient of variation of tidal volume, total cycle time, inspiratory time, expiratory time, mean inspiratory flow, duty cycle. The detection of chaos was performed with the noise titration technique. When present, chaos was characterized with numerical indexes (correlation dimension, irregularity; largest Lyapunov exponent, sensitivity to initial conditions). Expectedly, the coefficients of variations of the respiratory variables were higher during IPS than during ACV. During ACV, noise titration failed to detect nonlinearities in 12 patients who did not exhibit signs of spontaneous respiratory activity. This indicates that the mechanical properties of the respiratory system were not sufficient to produce ventilatory chaos in the presence of a nonlinear command (ventilator clock). A positive noise limit was found in the remaining 5 cases, but these patients exhibited signs of active expiratory control (highly variable expiratory time, respiratory frequency higher than the set frequency). A positive noise limit was also observed in 16/17 patients during IPS (p<0.001). These observations suggest that ventilatory chaos predominantly has a neural origin (intrinsic to the respiratory central pattern generators, resulting from their perturbation by respiratory afferents, or both), with little contribution of respiratory mechanics, if any.
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Affiliation(s)
- Laurence Mangin
- Université Paris 7 and Service de Physiologie-Explorations fonctionnelles, Hôpital Bichat, AP-HP, Paris, France.
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Lever NA, Newall EG, Larsen PD. Differences in the characteristics of induced and spontaneous episodes of ventricular fibrillation. ACTA ACUST UNITED AC 2007; 9:1054-8. [PMID: 17872925 DOI: 10.1093/europace/eum194] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AIMS The degree of organization of ventricular fibrillation (VF) can be examined in terms of the regularity of the electrical activity within the ventricle. Using electrograms (EGMs) stored within implanted cardioverter defibrillators (ICDs), we examined the hypothesis that the degree of organization, or regularity, was different if the VF was induced by electrical stimulation as opposed to occurring clinically due to ischemia or scar. METHODS AND RESULTS We compared the statistical characteristics of EGMs recorded by ICDs during spontaneous episodes with those induced during device testing in the laboratory in nine subjects. Regularity of the VF EGM signals was quantified using autocorrelation, Shannon entropy (derived from cycle to cycle activation complexes), and Kolmogorov entropy (derived from eight second long episodes of VF). All three measurements showed a statistically greater degree of regularity for induced VF than in spontaneous episodes. CONCLUSION Analysis of VF EGMs using these techniques is novel and robust, providing a new way for assessing electrical organization during VF. The clinical significance and utility of differences in VF waveform regularity is unclear at this stage.
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Affiliation(s)
- Nigel A Lever
- Department of Medicine, University of Auckland, Auckland, New Zealand
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