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Baedorf-Kassis E, Murn M, Dzierba AL, Serra AL, Garcia I, Minus E, Padilla C, Sarge T, Goodspeed VM, Matthay MA, Gong MN, Cook D, Loring SH, Talmor D, Beitler JR. Respiratory drive heterogeneity associated with systemic inflammation and vascular permeability in acute respiratory distress syndrome. Crit Care 2024; 28:136. [PMID: 38654391 PMCID: PMC11036740 DOI: 10.1186/s13054-024-04920-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 04/17/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND In acute respiratory distress syndrome (ARDS), respiratory drive often differs among patients with similar clinical characteristics. Readily observable factors like acid-base state, oxygenation, mechanics, and sedation depth do not fully explain drive heterogeneity. This study evaluated the relationship of systemic inflammation and vascular permeability markers with respiratory drive and clinical outcomes in ARDS. METHODS ARDS patients enrolled in the multicenter EPVent-2 trial with requisite data and plasma biomarkers were included. Neuromuscular blockade recipients were excluded. Respiratory drive was measured as PES0.1, the change in esophageal pressure during the first 0.1 s of inspiratory effort. Plasma angiopoietin-2, interleukin-6, and interleukin-8 were measured concomitantly, and 60-day clinical outcomes evaluated. RESULTS 54.8% of 124 included patients had detectable respiratory drive (PES0.1 range of 0-5.1 cm H2O). Angiopoietin-2 and interleukin-8, but not interleukin-6, were associated with respiratory drive independently of acid-base, oxygenation, respiratory mechanics, and sedation depth. Sedation depth was not significantly associated with PES0.1 in an unadjusted model, or after adjusting for mechanics and chemoreceptor input. However, upon adding angiopoietin-2, interleukin-6, or interleukin-8 to models, lighter sedation was significantly associated with higher PES0.1. Risk of death was less with moderate drive (PES0.1 of 0.5-2.9 cm H2O) compared to either lower drive (hazard ratio 1.58, 95% CI 0.82-3.05) or higher drive (2.63, 95% CI 1.21-5.70) (p = 0.049). CONCLUSIONS Among patients with ARDS, systemic inflammatory and vascular permeability markers were independently associated with higher respiratory drive. The heterogeneous response of respiratory drive to varying sedation depth may be explained in part by differences in inflammation and vascular permeability.
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Affiliation(s)
- Elias Baedorf-Kassis
- Division of Pulmonary and Critical Care Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Michael Murn
- Columbia Respiratory Critical Care Trials Group, Columbia University College of Physicians and Surgeons, and New York-Presbyterian Hospital, 622 West 168th Street, New York, NY, 10032, USA
- Center for Acute Respiratory Failure, New York-Presbyterian Hospital, New York, NY, USA
| | - Amy L Dzierba
- Columbia Respiratory Critical Care Trials Group, Columbia University College of Physicians and Surgeons, and New York-Presbyterian Hospital, 622 West 168th Street, New York, NY, 10032, USA
- Center for Acute Respiratory Failure, New York-Presbyterian Hospital, New York, NY, USA
- Department of Pharmacy, New York-Presbyterian Hospital, New York, NY, USA
| | - Alexis L Serra
- Columbia Respiratory Critical Care Trials Group, Columbia University College of Physicians and Surgeons, and New York-Presbyterian Hospital, 622 West 168th Street, New York, NY, 10032, USA
- Center for Acute Respiratory Failure, New York-Presbyterian Hospital, New York, NY, USA
| | - Ivan Garcia
- Columbia Respiratory Critical Care Trials Group, Columbia University College of Physicians and Surgeons, and New York-Presbyterian Hospital, 622 West 168th Street, New York, NY, 10032, USA
- Center for Acute Respiratory Failure, New York-Presbyterian Hospital, New York, NY, USA
| | - Emily Minus
- Departments of Medicine and Anesthesia, University of California San Francisco, San Francisco, CA, USA
| | - Clarissa Padilla
- Columbia Respiratory Critical Care Trials Group, Columbia University College of Physicians and Surgeons, and New York-Presbyterian Hospital, 622 West 168th Street, New York, NY, 10032, USA
- Center for Acute Respiratory Failure, New York-Presbyterian Hospital, New York, NY, USA
| | - Todd Sarge
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Valerie M Goodspeed
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Michael A Matthay
- Departments of Medicine and Anesthesia, University of California San Francisco, San Francisco, CA, USA
| | - Michelle N Gong
- Department of Critical Care Medicine, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY, USA
| | - Deborah Cook
- St. Joseph's Hospital and McMaster University, Hamilton, ON, Canada
| | - Stephen H Loring
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Daniel Talmor
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Jeremy R Beitler
- Columbia Respiratory Critical Care Trials Group, Columbia University College of Physicians and Surgeons, and New York-Presbyterian Hospital, 622 West 168th Street, New York, NY, 10032, USA.
- Center for Acute Respiratory Failure, New York-Presbyterian Hospital, New York, NY, USA.
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Adar O, Hollander A, Ilan Y. The Constrained Disorder Principle Accounts for the Variability That Characterizes Breathing: A Method for Treating Chronic Respiratory Diseases and Improving Mechanical Ventilation. Adv Respir Med 2023; 91:350-367. [PMID: 37736974 PMCID: PMC10514877 DOI: 10.3390/arm91050028] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/23/2023]
Abstract
Variability characterizes breathing, cellular respiration, and the underlying quantum effects. Variability serves as a mechanism for coping with changing environments; however, this hypothesis does not explain why many of the variable phenomena of respiration manifest randomness. According to the constrained disorder principle (CDP), living organisms are defined by their inherent disorder bounded by variable boundaries. The present paper describes the mechanisms of breathing and cellular respiration, focusing on their inherent variability. It defines how the CDP accounts for the variability and randomness in breathing and respiration. It also provides a scheme for the potential role of respiration variability in the energy balance in biological systems. The paper describes the option of using CDP-based artificial intelligence platforms to augment the respiratory process's efficiency, correct malfunctions, and treat disorders associated with the respiratory system.
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Affiliation(s)
- Ofek Adar
- Faculty of Medicine, Hebrew University, Jerusalem P.O. Box 1200, Israel; (O.A.); (A.H.)
- Department of Medicine, Hadassah Medical Center, Jerusalem P.O. Box 1200, Israel
| | - Adi Hollander
- Faculty of Medicine, Hebrew University, Jerusalem P.O. Box 1200, Israel; (O.A.); (A.H.)
- Department of Medicine, Hadassah Medical Center, Jerusalem P.O. Box 1200, Israel
| | - Yaron Ilan
- Faculty of Medicine, Hebrew University, Jerusalem P.O. Box 1200, Israel; (O.A.); (A.H.)
- Department of Medicine, Hadassah Medical Center, Jerusalem P.O. Box 1200, Israel
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3
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Sainju RK, Dragon DN, Winnike HB, Vilella L, Li X, Lhatoo S, Eyck PT, Wendt LH, Richerson GB, Gehlbach BK. Interictal respiratory variability predicts severity of hypoxemia after generalized convulsive seizures. Epilepsia 2023; 64:2373-2384. [PMID: 37344924 PMCID: PMC10538446 DOI: 10.1111/epi.17691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/19/2023] [Accepted: 06/19/2023] [Indexed: 06/23/2023]
Abstract
OBJECTIVE Severe respiratory dysfunction induced by generalized convulsive seizures (GCS) is now thought to be a common mechanism for sudden unexpected death in epilepsy (SUDEP). In a mouse model of seizure-induced death, increased interictal respiratory variability was reported in mice that later died of respiratory arrest after GCS. We studied respiratory variability in epilepsy patients as a predictive tool for severity of postictal hypoxemia, a potential biomarker for SUDEP risk. We then explored the relationship between respiratory variability and central CO2 drive, measured by the hypercapnic ventilatory response (HCVR). METHODS We reviewed clinical, video-electroencephalography, and respiratory (belts, airflow, pulse oximeter, and HCVR) data of epilepsy patients. Mean, SD, and coefficient of variation (CV) of interbreath interval (IBI) were calculated. Primary outcomes were: (1) nadir of capillary oxygen saturation (SpO2 ) and (2) duration of oxygen desaturation. Poincaré plots of IBI were created. Covariates were evaluated in univariate models, then, based on Akaike information criteria (AIC), multivariate regression models were created. RESULTS Of 66 GCS recorded in 131 subjects, 30 had interpretable respiratory data. In the multivariate model with the lowest AIC value, duration of epilepsy was a significant predictor of duration of oxygen desaturation. Duration of tonic phase and CV of IBI during the third postictal minute correlated with SpO2 nadir, whereas CV of IBI during non-rapid eye movement sleep had a negative correlation. Poincaré plots showed that long-term variability was significantly greater in subjects with ≥200 s of postictal oxygen desaturation after GCS compared to those with <200 s desaturation. Finally, HCVR slope showed a negative correlation with measures of respiratory variability. SIGNIFICANCE These results indicate that interictal respiratory variability predicts severity of postictal oxygen desaturation, suggesting its utility as a potential biomarker. They also suggest that interictal respiratory control may be abnormal in some patients with epilepsy.
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Affiliation(s)
- Rup K. Sainju
- Department of Neurology University of Iowa Hospitals and Clinics, Iowa City, IA
| | - Deidre N. Dragon
- Department of Neurology University of Iowa Hospitals and Clinics, Iowa City, IA
| | - Harold B. Winnike
- Institute for Clinical and Translational Science University of Iowa, Iowa City, IA
| | - Laura Vilella
- Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX
| | - Xiaojin Li
- Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX
| | - Samden Lhatoo
- Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX
| | - Patrick Ten Eyck
- Institute for Clinical and Translational Science University of Iowa, Iowa City, IA
| | - Linder H Wendt
- Institute for Clinical and Translational Science University of Iowa, Iowa City, IA
| | - George B. Richerson
- Department of Neurology University of Iowa Hospitals and Clinics, Iowa City, IA
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA
- Iowa Neuroscience Institute, University of Iowa, IA
- VA Medical Center, Iowa City, IA
| | - Brian K. Gehlbach
- Department of Internal Medicine, University of Iowa Hospitals and Clinics, Iowa City, IA
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Ogawa F, Oi Y, Honzawa H, Misawa N, Takeda T, Kikuchi Y, Fukui R, Tanaka K, Kano D, Kato H, Abe T, Takeuchi I. Severity predictors of COVID-19 in SARS-CoV-2 variant, delta and omicron period; single center study. PLoS One 2022; 17:e0273134. [PMID: 36282812 PMCID: PMC9595523 DOI: 10.1371/journal.pone.0273134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/09/2022] [Indexed: 11/05/2022] Open
Abstract
Background The outcomes of coronavirus disease 2019 (COVID-19) treatment have improved due to vaccination and the establishment of better treatment regimens. However, the emergence of variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes COVID-19, and the corresponding changes in the characteristics of the disease present new challenges in patient management. This study aimed to analyze predictors of COVID-19 severity caused by the delta and omicron variants of SARS-CoV-2. Methods We retrospectively analyzed the data of patients who were admitted for COVID-19 at Yokohama City University Hospital from August 2021 to March 2022. Results A total of 141 patients were included in this study. Of these, 91 had moderate COVID-19, whereas 50 had severe COVID-19. There were significant differences in sex, vaccination status, dyspnea, sore throat symptoms, and body mass index (BMI) (p <0.0001, p <0.001, p <0.001, p = 0.02, p< 0.0001, respectively) between the moderate and severe COVID-19 groups. Regarding comorbidities, smoking habit and renal dysfunction were significantly different between the two groups (p = 0.007 and p = 0.01, respectively). Regarding laboratory data, only LDH level on the first day of hospitalization was significantly different between the two groups (p<0.001). Multiple logistic regression analysis revealed that time from the onset of COVID-19 to hospitalization, BMI, smoking habit, and LDH level were significantly different between the two groups (p<0.03, p = 0.039, p = 0.008, p<0.001, respectively). The cut-off value for the time from onset of COVID-19 to hospitalization was four days (sensitivity, 0.73; specificity, 0.70). Conclusions Time from the onset of COVID-19 to hospitalization is the most important factor in the prevention of the aggravation of COVID-19 caused by the delta and omicron SARS-CoV-2 variants. Appropriate medical management within four days after the onset of COVID-19 is essential for preventing the progression of COVID-19, especially in patients with smoking habits.
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Affiliation(s)
- Fumihiro Ogawa
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
- * E-mail:
| | - Yasufumi Oi
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
| | - Hiroshi Honzawa
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
| | - Naho Misawa
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
| | - Tomoaki Takeda
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
| | - Yushi Kikuchi
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
| | - Ryosuke Fukui
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
| | - Katsushi Tanaka
- Infection Prevention and Control Department, Yokohama City University Hospital, Yokohama, Kanagawa, Japan
| | - Daiki Kano
- Infection Prevention and Control Department, Yokohama City University Hospital, Yokohama, Kanagawa, Japan
| | - Hideaki Kato
- Infection Prevention and Control Department, Yokohama City University Hospital, Yokohama, Kanagawa, Japan
| | - Takeru Abe
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
| | - Ichiro Takeuchi
- Department of Emergency Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan
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5
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Doerschug KC. Patient-Ventilator Synchrony. Clin Chest Med 2022; 43:511-518. [PMID: 36116818 DOI: 10.1016/j.ccm.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Patient-ventilator asynchrony develops when the ventilator output does not match the efforts of the patient and contributes to excess work of breathing, lung injury, and mortality. Asynchronies are categorized as trigger (breath initiation), flow (delivery of the breath), and cycle (transition from inspiration to expiration). Clinicians should be skilled at ventilator waveform analysis to detect patient-ventilator asynchronies and make informed ventilator adjustments. Ventilator overdrive suppresses respiratory drive and reduces asynchrony, while other adjustments specific to the asynchrony are also useful.
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Affiliation(s)
- Kevin C Doerschug
- Department of Internal Medicine, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52246, USA.
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6
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Klinnikova AA, Danilova GA, Aleksandrova NP. Role of Nitric Oxide Synthase Pathways in the Effects of Proinflammatory Cytokines on the Respiratory Pattern and Hypoxic Ventilatory Response. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021060168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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van den Bosch OFC, Alvarez-Jimenez R, de Grooth HJ, Girbes ARJ, Loer SA. Breathing variability-implications for anaesthesiology and intensive care. Crit Care 2021; 25:280. [PMID: 34353348 PMCID: PMC8339683 DOI: 10.1186/s13054-021-03716-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 07/29/2021] [Indexed: 12/04/2022] Open
Abstract
The respiratory system reacts instantaneously to intrinsic and extrinsic inputs. This adaptability results in significant fluctuations in breathing parameters, such as respiratory rate, tidal volume, and inspiratory flow profiles. Breathing variability is influenced by several conditions, including sleep, various pulmonary diseases, hypoxia, and anxiety disorders. Recent studies have suggested that weaning failure during mechanical ventilation may be predicted by low respiratory variability. This review describes methods for quantifying breathing variability, summarises the conditions and comorbidities that affect breathing variability, and discusses the potential implications of breathing variability for anaesthesia and intensive care.
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Affiliation(s)
- Oscar F C van den Bosch
- Departments of Anesthesiology and Intensive Care, Amsterdam UMC, VUMC, ZH 6F 003, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Ricardo Alvarez-Jimenez
- Departments of Anesthesiology and Intensive Care, Amsterdam UMC, VUMC, ZH 6F 003, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Harm-Jan de Grooth
- Departments of Anesthesiology and Intensive Care, Amsterdam UMC, VUMC, ZH 6F 003, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Armand R J Girbes
- Departments of Anesthesiology and Intensive Care, Amsterdam UMC, VUMC, ZH 6F 003, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Stephan A Loer
- Departments of Anesthesiology and Intensive Care, Amsterdam UMC, VUMC, ZH 6F 003, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
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Aleksandrova NP, Klinnikova AA, Danilova GA. Cyclooxygenase and nitric oxide synthase pathways mediate the respiratory effects of TNF-α in rats. Respir Physiol Neurobiol 2020; 284:103567. [PMID: 33161117 DOI: 10.1016/j.resp.2020.103567] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/23/2020] [Accepted: 10/25/2020] [Indexed: 01/22/2023]
Abstract
TNF-α is the key inflammatory cytokine. TNF-α receptors are expressed in brain stem regions involved in respiratory control and also in the carotid bodies, which are the sensory organs monitoring arterial blood O2. We hypothesised that the circulating tumour necrosis factor (TNF)-α may affect the lung ventilation and modulate the hypoxic ventilatory response via activation of cyclooxygenase (COX) and nitric oxide synthase (NOS) pathways. The aim of the current study was to compare the respiratory effects of TNF-α before and after pretreatment with diclofenac or L-NG-nitro arginine methyl ester (L-NAME) nonspecific inhibitors of COX and NOS, respectively. The hypoxic ventilatory response was measured in anaesthetised rats using rebreathing techniques. We found that TNF-α increased the lung ventilation in normoxia but decreased the ventilatory response to hypoxia. Pretreatment with each of these inhibitors reduced respiratory effects of TNF-α. We believe that activation of COX and NOS-related pathways and also "cross-talk" between them mediates the TNF-α respiratory effects and underlies the impact of inflammation on the respiratory function.
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Affiliation(s)
- Nina Pavlovna Aleksandrova
- Head of Laboratory of Respiratory Physiology, Pavlov Institute of Physiology of RAS, nab Makarova6, St.-Petersburg, Russian Federation.
| | - Anna Andreevna Klinnikova
- Researcher of Laboratory of Respiratory Physiology, Pavlov Institute of Physiology of RAS, nab Makarova6, St.-Petersburg, Russian Federation.
| | - Galina Anatolevna Danilova
- Researcher of Laboratory of Respiratory Physiology, Pavlov Institute of Physiology of RAS, nab Makarova6, St.-Petersburg, Russian Federation.
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Tobin MJ, Laghi F, Jubran A. Why COVID-19 Silent Hypoxemia Is Baffling to Physicians. Am J Respir Crit Care Med 2020; 202:356-360. [PMID: 32539537 PMCID: PMC7397783 DOI: 10.1164/rccm.202006-2157cp] [Citation(s) in RCA: 353] [Impact Index Per Article: 88.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 06/15/2020] [Indexed: 02/07/2023] Open
Abstract
Patients with coronavirus disease (COVID-19) are described as exhibiting oxygen levels incompatible with life without dyspnea. The pairing-dubbed happy hypoxia but more precisely termed silent hypoxemia-is especially bewildering to physicians and is considered as defying basic biology. This combination has attracted extensive coverage in media but has not been discussed in medical journals. It is possible that coronavirus has an idiosyncratic action on receptors involved in chemosensitivity to oxygen, but well-established pathophysiological mechanisms can account for most, if not all, cases of silent hypoxemia. These mechanisms include the way dyspnea and the respiratory centers respond to low levels of oxygen, the way the prevailing carbon dioxide tension (PaCO2) blunts the brain's response to hypoxia, effects of disease and age on control of breathing, inaccuracy of pulse oximetry at low oxygen saturations, and temperature-induced shifts in the oxygen dissociation curve. Without knowledge of these mechanisms, physicians caring for patients with hypoxemia free of dyspnea are operating in the dark, placing vulnerable patients with COVID-19 at considerable risk. In conclusion, features of COVID-19 that physicians find baffling become less strange when viewed in light of long-established principles of respiratory physiology; an understanding of these mechanisms will enhance patient care if the much-anticipated second wave emerges.
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Affiliation(s)
- Martin J Tobin
- Division of Pulmonary and Critical Care Medicine, Hines Veterans Affairs Hospital and Loyola University of Chicago Stritch School of Medicine, Hines, Illinois
| | - Franco Laghi
- Division of Pulmonary and Critical Care Medicine, Hines Veterans Affairs Hospital and Loyola University of Chicago Stritch School of Medicine, Hines, Illinois
| | - Amal Jubran
- Division of Pulmonary and Critical Care Medicine, Hines Veterans Affairs Hospital and Loyola University of Chicago Stritch School of Medicine, Hines, Illinois
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Knox KE, Nava-Guerra L, Hotz JC, Newth CJL, Khoo MCK, Khemani RG. High Breath-by-Breath Variability Is Associated With Extubation Failure in Children. Crit Care Med 2020; 48:1165-1174. [PMID: 32697487 PMCID: PMC7755301 DOI: 10.1097/ccm.0000000000004418] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Extubation failure is multifactorial, and most tools to assess extubation readiness only evaluate snapshots of patient physiology. Understanding variability in respiratory variables may provide additional information to inform extubation readiness assessments. DESIGN Secondary analysis of prospectively collected physiologic data of children just prior to extubation during a spontaneous breathing trial. Physiologic data were cleaned to provide 40 consecutive breaths and calculate variability terms, coefficient of variation and autocorrelation, in commonly used respiratory variables (i.e., tidal volume, minute ventilation, and respiratory rate). Other clinical variables included diagnostic and demographic data, median values of respiratory variables during spontaneous breathing trials, and the change in airway pressure during an occlusion maneuver to measure respiratory muscle strength (maximal change in airway pressure generated during airway occlusion [PiMax]). Multivariable models evaluated independent associations with reintubation and prolonged use of noninvasive respiratory support after extubation. SETTING Acute care, children's hospital. PATIENTS Children were included from the pediatric and cardiothoracic ICUs who were greater than 37 weeks gestational age up to and including 18 years who were intubated greater than or equal to 12 hours with planned extubation. We excluded children who had a contraindication to an esophageal catheter or respiratory inductance plethysmography bands. INTERVENTIONS Noninterventional study. MEASUREMENTS AND MAIN RESULTS A total of 371 children were included, 32 of them were reintubated. Many variability terms were associated with reintubation, including coefficient of variation and autocorrelation of the respiratory rate. After controlling for confounding variables such as age and neurologic diagnosis, both coefficient of variation of respiratory rate(p < 0.001) and low PiMax (p = 0.002) retained an independent association with reintubation. Children with either low PiMax or high coefficient of variation of respiratory rate had a nearly three-fold higher risk of extubation failure, and when these children developed postextubation upper airway obstruction, reintubation rates were greater than 30%. CONCLUSIONS High respiratory variability during spontaneous breathing trials is independently associated with extubation failure in children, with very high rates of extubation failure when these children develop postextubation upper airway obstruction.
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Affiliation(s)
- Kelby E Knox
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, CA
| | - Leonardo Nava-Guerra
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, CA
- Department of Neonatology, Children's Hospital Los Angeles, Los Angeles, CA
| | - Justin C Hotz
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, CA
| | - Christopher J L Newth
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, CA
- Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, CA
| | - Michael C K Khoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA
| | - Robinder G Khemani
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, CA
- Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, CA
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11
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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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12
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Melssen MM, Petroni GR, Chianese-Bullock KA, Wages NA, Grosh WW, Varhegyi N, Smolkin ME, Smith KT, Galeassi NV, Deacon DH, Gaughan EM, Slingluff CL. A multipeptide vaccine plus toll-like receptor agonists LPS or polyICLC in combination with incomplete Freund's adjuvant in melanoma patients. J Immunother Cancer 2019; 7:163. [PMID: 31248461 PMCID: PMC6598303 DOI: 10.1186/s40425-019-0625-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 05/17/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Cancer vaccines require adjuvants to induce effective immune responses; however, there is no consensus on optimal adjuvants. We hypothesized that toll-like receptor (TLR)3 agonist polyICLC or TLR4 agonist lipopolysaccharide (LPS), combined with CD4 T cell activation, would support strong and durable CD8+ T cell responses, whereas addition of an incomplete Freund's adjuvant (IFA) would reduce magnitude and persistence of immune responses. PATIENTS AND METHODS Participants with resected stage IIB-IV melanoma received a vaccine comprised of 12 melanoma peptides restricted by Class I MHC (12MP), plus a tetanus helper peptide (Tet). Participants were randomly assigned 2:1 to cohort 1 (LPS dose-escalation) or cohort 2 (polyICLC). Each cohort included 3 subgroups (a-c), receiving 12MP + Tet + TLR agonist without IFA (0), or with IFA in vaccine one (V1), or all six vaccines (V6). Toxicities were recorded (CTCAE v4). T cell responses were measured with IFNγ ELIspot assay ex vivo or after one in vitro stimulation (IVS). RESULTS Fifty-three eligible patients were enrolled, of which fifty-one were treated. Treatment-related dose-limiting toxicities (DLTs) were observed in 0/33 patients in cohort 1 and in 2/18 patients in cohort 2 (11%). CD8 T cell responses to 12MP were detected ex vivo in cohort 1 (42%) and in cohort 2 (56%) and in 18, 50, and 72% for subgroups V0, V1, and V6, respectively. T cell responses to melanoma peptides were more durable and of highest magnitude for IFA V6. CONCLUSIONS LPS and polyICLC are safe and effective vaccine adjuvants when combined with IFA. Contrary to the central hypothesis, IFA enhanced T cell responses to peptide vaccines when added to TLR agonists. Future studies will aim to understand mechanisms underlying the favorable effects with IFA. TRIAL REGISTRATION The clinical trial Mel58 was performed with IRB (#15781) and FDA approval and is registered with Clinicaltrials.gov on April 25, 2012 (NCT01585350). Patients provided written informed consent to participate. Enrollment started on June 24, 2012.
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Affiliation(s)
- Marit M Melssen
- Department of Surgery/Division of Surgical Oncology and the Human Immune Therapy Center, Cancer Center, University of Virginia, 1352 Pinn Hall, P.O. Box 801457, Charlottesville, VA, 22908, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Gina R Petroni
- Department of Public Health Sciences/Division of Translational Research & Applied Statistics, University of Virginia, Charlottesville, VA, USA
| | - Kimberly A Chianese-Bullock
- Department of Surgery/Division of Surgical Oncology and the Human Immune Therapy Center, Cancer Center, University of Virginia, 1352 Pinn Hall, P.O. Box 801457, Charlottesville, VA, 22908, USA
| | - Nolan A Wages
- Department of Public Health Sciences/Division of Translational Research & Applied Statistics, University of Virginia, Charlottesville, VA, USA
| | - William W Grosh
- Department of Medicine/Division of Hematology/Oncology, University of Virginia, Charlottesville, VA, USA
| | - Nikole Varhegyi
- Department of Public Health Sciences/Division of Translational Research & Applied Statistics, University of Virginia, Charlottesville, VA, USA
| | - Mark E Smolkin
- Department of Public Health Sciences/Division of Translational Research & Applied Statistics, University of Virginia, Charlottesville, VA, USA
| | - Kelly T Smith
- Department of Surgery/Division of Surgical Oncology and the Human Immune Therapy Center, Cancer Center, University of Virginia, 1352 Pinn Hall, P.O. Box 801457, Charlottesville, VA, 22908, USA
| | - Nadejda V Galeassi
- Department of Surgery/Division of Surgical Oncology and the Human Immune Therapy Center, Cancer Center, University of Virginia, 1352 Pinn Hall, P.O. Box 801457, Charlottesville, VA, 22908, USA
| | - Donna H Deacon
- Department of Surgery/Division of Surgical Oncology and the Human Immune Therapy Center, Cancer Center, University of Virginia, 1352 Pinn Hall, P.O. Box 801457, Charlottesville, VA, 22908, USA
| | - Elizabeth M Gaughan
- Department of Medicine/Division of Hematology/Oncology, University of Virginia, Charlottesville, VA, USA
| | - Craig L Slingluff
- Department of Surgery/Division of Surgical Oncology and the Human Immune Therapy Center, Cancer Center, University of Virginia, 1352 Pinn Hall, P.O. Box 801457, Charlottesville, VA, 22908, USA.
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13
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Peña-Ortega F. Clinical and experimental aspects of breathing modulation by inflammation. Auton Neurosci 2018; 216:72-86. [PMID: 30503161 DOI: 10.1016/j.autneu.2018.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 12/19/2022]
Abstract
Neuroinflammation is produced by local or systemic alterations and mediated mainly by glia, affecting the activity of various neural circuits including those involved in breathing rhythm generation and control. Several pathological conditions, such as sudden infant death syndrome, obstructive sleep apnea and asthma exert an inflammatory influence on breathing-related circuits. Consequently breathing (both resting and ventilatory responses to physiological challenges), is affected; e.g., responses to hypoxia and hypercapnia are compromised. Moreover, inflammation can induce long-lasting changes in breathing and affect adaptive plasticity; e.g., hypoxic acclimatization or long-term facilitation. Mediators of the influences of inflammation on breathing are most likely proinflammatory molecules such as cytokines and prostaglandins. The focus of this review is to summarize the available information concerning the modulation of the breathing function by inflammation and the cellular and molecular aspects of this process. I will consider: 1) some clinical and experimental conditions in which inflammation influences breathing; 2) the variety of experimental approaches used to understand this inflammatory modulation; 3) the likely cellular and molecular mechanisms.
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Affiliation(s)
- Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México.
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14
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Brochard L, Slutsky A, Pesenti A. Mechanical Ventilation to Minimize Progression of Lung Injury in Acute Respiratory Failure. Am J Respir Crit Care Med 2017; 195:438-442. [PMID: 27626833 DOI: 10.1164/rccm.201605-1081cp] [Citation(s) in RCA: 685] [Impact Index Per Article: 97.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mechanical ventilation is used to sustain life in patients with acute respiratory failure. A major concern in mechanically ventilated patients is the risk of ventilator-induced lung injury, which is partially prevented by lung-protective ventilation. Spontaneously breathing, nonintubated patients with acute respiratory failure may have a high respiratory drive and breathe with large tidal volumes and potentially injurious transpulmonary pressure swings. In patients with existing lung injury, regional forces generated by the respiratory muscles may lead to injurious effects on a regional level. In addition, the increase in transmural pulmonary vascular pressure swings caused by inspiratory effort may worsen vascular leakage. Recent data suggest that these patients may develop lung injury that is similar to the ventilator-induced lung injury observed in mechanically ventilated patients. As such, we argue that application of a lung-protective ventilation, today best applied with sedation and endotracheal intubation, might be considered a prophylactic therapy, rather than just a supportive therapy, to minimize the progression of lung injury from a form of patient self-inflicted lung injury. This has important implications for the management of these patients.
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Affiliation(s)
- Laurent Brochard
- 1 Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, Ontario, Canada.,2 Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Arthur Slutsky
- 1 Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, Ontario, Canada.,2 Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Antonio Pesenti
- 3 Department of Anesthesia, Critical Care, and Emergency, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy; and.,4 Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milan, Milan, Italy
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15
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Aleksandrova NP, Danilova GA, Aleksandrov VG. Interleukin-1beta suppresses the ventilatory hypoxic response in rats via prostaglandin-dependent pathways. Can J Physiol Pharmacol 2017; 95:681-685. [DOI: 10.1139/cjpp-2016-0419] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the effect of the major inflammatory cytokine interleukin-1beta (IL-1β) on the ventilatory response to hypoxia. The goal was to test the hypothesis that IL-1β impairs the hypoxic ventilatory response in vivo by indirectly inhibiting respiratory neurons in the brainstem via prostaglandins. Thus, IL-1β was delivered by cerebroventricular injection, and the ventilatory hypoxic response was assessed in anesthetized, spontaneously breathing rats pretreated with or without diclofenac, a nonspecific inhibitor of prostaglandin synthesis. We found that the slope of the ventilatory response to hypoxia decreased almost 2-fold from 10.4 ± 3.02 to 4.06 ± 0.86 mL·min−1·(mm Hg)−1 (–61%) 90 min after administration of IL-1β (p < 0.05). The slope of tidal volume and mean inspiratory flow also decreased from 0.074 ± 0.02 to 0.039 ± 0.01 mL·(mm Hg)−1 (–45%, p < 0.05), and from 0.36 ± 0.07 to 0.2 ± 0.04 mL·s−1·(mm Hg)−1 (–46%, p < 0.05), respectively. Pretreatment with diclofenac blocked these effects. Thus, the data indicate that IL-1β degrades the ventilatory hypoxic response by stimulating production of prostaglandin. The increase of cerebral levels of IL-1β, which is induced by the activation of immune cells in the brain, may impair respiratory chemoreflexes.
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Affiliation(s)
- Nina P. Aleksandrova
- Respiratory Physiology Lab, Pavlov Institute of Physiology RAS, nab. Makarova, 6, Saint-Petersburg, 199034, Russian Federation
- Respiratory Physiology Lab, Pavlov Institute of Physiology RAS, nab. Makarova, 6, Saint-Petersburg, 199034, Russian Federation
| | - Galina A. Danilova
- Respiratory Physiology Lab, Pavlov Institute of Physiology RAS, nab. Makarova, 6, Saint-Petersburg, 199034, Russian Federation
- Respiratory Physiology Lab, Pavlov Institute of Physiology RAS, nab. Makarova, 6, Saint-Petersburg, 199034, Russian Federation
| | - Viacheslav G. Aleksandrov
- Respiratory Physiology Lab, Pavlov Institute of Physiology RAS, nab. Makarova, 6, Saint-Petersburg, 199034, Russian Federation
- Respiratory Physiology Lab, Pavlov Institute of Physiology RAS, nab. Makarova, 6, Saint-Petersburg, 199034, Russian Federation
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16
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Peña-Ortega F. Pharmacological Tools to Activate Microglia and their Possible use to Study Neural Network Patho-physiology. Curr Neuropharmacol 2017; 15:595-619. [PMID: 27697040 PMCID: PMC5543677 DOI: 10.2174/1570159x14666160928151546] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/05/2016] [Accepted: 09/26/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Microglia are the resident immunocompetent cells of the CNS and also constitute a unique cell type that contributes to neural network homeostasis and function. Understanding microglia cell-signaling not only will reveal their diverse functions but also will help to identify pharmacological and non-pharmacological tools to modulate the activity of these cells. METHODS We undertook a search of bibliographic databases for peer-reviewed research literature to identify microglial activators and their cell-specificity. We also looked for their effects on neural network function and dysfunction. RESULTS We identified several pharmacological targets to modulate microglial function, which are more or less specific (with the proper control experiments). We also identified pharmacological targets that would require the development of new potent and specific modulators. We identified a wealth of evidence about the participation of microglia in neural network function and their alterations in pathological conditions. CONCLUSION The identification of specific microglia-activating signals provides experimental tools to modulate the activity of this heterogeneous cell type in order to evaluate its impact on other components of the nervous system, and it also helps to identify therapeutic approaches to ease some pathological conditions related to microglial dysfunction.
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Affiliation(s)
- Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM-Campus Juriquilla, México
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17
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Yang CH, Hsiao JL, Wu MF, Lu MH, Chang HM, Ko WS, Chiou YL. The declined levels of inflammatory cytokines related with weaning rate during period of septic patients using ventilators. CLINICAL RESPIRATORY JOURNAL 2016; 12:772-778. [PMID: 27925446 DOI: 10.1111/crj.12593] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 11/04/2016] [Accepted: 11/11/2016] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Approximately 50% of patients with sepsis-induced acute lung injury and acute respiratory distress syndrome require mechanical ventilation. Patients with extended mechanical ventilator use routinely develop reinfections, which increases hospital stay, mortality, and health care cost. Some studies have pointed out inflammatory factors concentrations can affect ventilator weaning, but do not indicate changed inflammatory factors related to ventilator weaning during using ventilators. OBJECTIVES This study aimed to investigate during period of septic patients using ventilators, the inflammatory cytokines concentrations related with weaning rate. METHODS Blood was collected from 35 septic patients before and during ventilator use on days 1, 7, 14, and 21 (or weaning). RESULTS 58.3% (N = 20) of septic patients with mechanical ventilators were weaned successfully within 21 days (ventilator weaned group, VW), 16.7% (N = 6) did not wean within 21 days (ventilator dependent group, VD), and 25% died (death group) in hospital. Before ventilator use, higher C-reactive protein (CRP), IL-6, and IL-8 levels were measured in the death group than in all other groups (P < .05). During ventilator use, CRP, IL-6, and IL-8 concentrations declined significantly in VW and VD patients (P < .05). In addition, IL-6 concentrations in the VW group were significantly lower than in the VD group at 14 and 21 days (P < .05). CONCLUSION The factors of ventilators weaning successfully such as disease control, nutritional status, and so on. The declined levels of serum inflammatory cytokines, especially IL-6, improved inflammation status might be one factor of successfully weaning during septic patients on ventilators.
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Affiliation(s)
- Chao-Huei Yang
- Department of Pulmonary Medicine, Kuang-Tien General Hospital, Taichung, Taiwan, Republic of China
| | - Jung-Lung Hsiao
- Department of Critical Care Medicine, Kuang-Tien General Hospital, Taichung, Taiwan, Republic of China
| | - Ming-Feng Wu
- Department of Internal Medicine, Kuang-Tien General Hospital, Taichung, Taiwan, Republic of China
| | - Mei-Hua Lu
- Department of Nursing, Kuang-Tien General Hospital, Taichung, Taiwan, Republic of China
| | - Hui-Ming Chang
- Department of Nursing, Kuang-Tien General Hospital, Taichung, Taiwan, Republic of China
| | - Wang-Sheng Ko
- Department of Internal Medicine, Kuang-Tien General Hospital, Taichung, Taiwan, Republic of China.,Department of Nutrition and Institute of BioMedical Nutrition, Hungkuang University, Taichung, Taiwan, Republic of China
| | - Ya-Ling Chiou
- Department of Nutrition and Institute of BioMedical Nutrition, Hungkuang University, Taichung, Taiwan, Republic of China
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18
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Goto Y, Katayama S, Shono A, Mori Y, Miyazaki Y, Sato Y, Ozaki M, Kotani T. Roles of neurally adjusted ventilatory assist in improving gas exchange in a severe acute respiratory distress syndrome patient after weaning from extracorporeal membrane oxygenation: a case report. J Intensive Care 2016; 4:26. [PMID: 27057312 PMCID: PMC4823850 DOI: 10.1186/s40560-016-0153-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/31/2016] [Indexed: 02/06/2023] Open
Abstract
Background Patient-ventilator asynchrony is a major cause of difficult weaning from mechanical ventilation. Neurally adjusted ventilatory assist (NAVA) is reported useful to improve the synchrony in patients with sustained low lung compliance. However, the role of NAVA has not been fully investigated. Case presentation The patient was a 63-year-old Japanese man with acute respiratory distress syndrome secondary to respiratory infection. He was treated with extracorporeal membrane oxygenation for 7 days and survived. Dynamic compliance at withdrawal of extracorporeal membrane oxygenation decreased to 20 ml/cmH2O or less, but gas exchange was maintained by full support with assist/control mode. However, weaning from mechanical ventilation using a flow trigger failed repeatedly because of patient-ventilator asynchrony with hypercapnic acidosis during partial ventilator support despite using different types of ventilators and different trigger levels. Weaning using NAVA restored the regular respiration and stable and normal acid-base balance. Electromyographic analysis of the diaphragm clearly showed improved triggering of both the start and the end of spontaneous inspiration. Regional ventilation monitoring using electrical impedance tomography showed an increase in tidal volume and a ventilation shift to the dorsal regions during NAVA, indicating that NAVA could deliver gas flow to the dorsal regions to adjust for the magnitude of diaphragmatic excursion. NAVA was applied for 31 days, followed by partial ventilatory support with a conventional flow trigger. The patient was discharged from the intensive care unit on day 110 and has recovered enough to be able to live without a ventilatory support for 5 h per day. Conclusion Our experience showed that NAVA improved not only patient-ventilator synchrony but also regional ventilation distribution in an acute respiratory distress patient with sustained low lung compliance.
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Affiliation(s)
- Yuya Goto
- Department of Anesthesiology and Intensive Care Medicine, Tokyo Women's Medical University, Tokyo, 162-8666 Japan
| | - Shinshu Katayama
- Department of Anesthesiology and Intensive Care Medicine, Tokyo Women's Medical University, Tokyo, 162-8666 Japan
| | - Atsuko Shono
- Department of Anesthesiology, Shimane University, Shimane, 693-8501 Japan
| | - Yosuke Mori
- Department of Anesthesiology and Intensive Care Medicine, Tokyo Women's Medical University, Tokyo, 162-8666 Japan
| | - Yuya Miyazaki
- Department of Anesthesiology and Intensive Care Medicine, Tokyo Women's Medical University, Tokyo, 162-8666 Japan
| | - Yoko Sato
- Department of Anesthesiology and Intensive Care Medicine, Tokyo Women's Medical University, Tokyo, 162-8666 Japan
| | - Makoto Ozaki
- Department of Anesthesiology and Intensive Care Medicine, Tokyo Women's Medical University, Tokyo, 162-8666 Japan
| | - Toru Kotani
- Department of Anesthesiology and Intensive Care Medicine, Tokyo Women's Medical University, Tokyo, 162-8666 Japan
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19
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Lorea-Hernández JJ, Morales T, Rivera-Angulo AJ, Alcantara-Gonzalez D, Peña-Ortega F. Microglia modulate respiratory rhythm generation and autoresuscitation. Glia 2015; 64:603-19. [DOI: 10.1002/glia.22951] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 11/18/2015] [Accepted: 11/18/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Jonathan-Julio Lorea-Hernández
- Departamento de Neurobiología del Desarrollo y Neurofisiología; Instituto De Neurobiología, UNAM Campus Juriquilla; Querétaro México
| | - Teresa Morales
- Departamento de Neurobiología del Desarrollo y Neurofisiología; Instituto De Neurobiología, UNAM Campus Juriquilla; Querétaro México
| | - Ana-Julia Rivera-Angulo
- Departamento de Neurobiología del Desarrollo y Neurofisiología; Instituto De Neurobiología, UNAM Campus Juriquilla; Querétaro México
| | - David Alcantara-Gonzalez
- Departamento de Neurobiología del Desarrollo y Neurofisiología; Instituto De Neurobiología, UNAM Campus Juriquilla; Querétaro México
| | - Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología; Instituto De Neurobiología, UNAM Campus Juriquilla; Querétaro México
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20
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Lipopolysaccharides-Induced Inflammatory Response in White Blood Cells Is Associated with Alterations in Senescence Mediators: Modulation by Metformin. Metab Syndr Relat Disord 2015; 13:278-85. [DOI: 10.1089/met.2014.0168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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21
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Cyclooxygenase pathway in modulation of the ventilatory response to hypercapnia by interleukin-1β in rats. Respir Physiol Neurobiol 2015; 209:85-90. [DOI: 10.1016/j.resp.2014.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 12/07/2014] [Accepted: 12/07/2014] [Indexed: 01/08/2023]
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22
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Plessers E, Wyns H, Watteyn A, Pardon B, De Backer P, Croubels S. Characterization of an intravenous lipopolysaccharide inflammation model in calves with respect to the acute-phase response. Vet Immunol Immunopathol 2015; 163:46-56. [DOI: 10.1016/j.vetimm.2014.11.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/29/2014] [Accepted: 11/06/2014] [Indexed: 11/30/2022]
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Brochard L. Variability is adaptability…also during weaning! CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:127. [PMID: 25029030 PMCID: PMC4057288 DOI: 10.1186/cc13807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Heart rate variability in the frequency domain can now be obtained at the bedside in the ICU. Promising data suggest that it may help to characterize a patient response to a spontaneous breathing trial. Refinement of the analysis could even help to predict the outcome of extubation or at least help to detect early patients at risk of failure. It is possible that combining this type of analysis, the breathing pattern variability, and other objective indices could help clinicians in the decision-making process of weaning and extubation.
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Aerts JM, Haddad WM, An G, Vodovotz Y. From data patterns to mechanistic models in acute critical illness. J Crit Care 2014; 29:604-10. [PMID: 24768566 DOI: 10.1016/j.jcrc.2014.03.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 03/14/2014] [Accepted: 03/14/2014] [Indexed: 12/13/2022]
Abstract
The complexity of the physiologic and inflammatory response in acute critical illness has stymied the accurate diagnosis and development of therapies. The Society for Complex Acute Illness was formed a decade ago with the goal of leveraging multiple complex systems approaches to address this unmet need. Two main paths of development have characterized the society's approach: (i) data pattern analysis, either defining the diagnostic/prognostic utility of complexity metrics of physiologic signals or multivariate analyses of molecular and genetic data and (ii) mechanistic mathematical and computational modeling, all being performed with an explicit translational goal. Here, we summarize the progress to date on each of these approaches, along with pitfalls inherent in the use of each approach alone. We suggest that the next decade holds the potential to merge these approaches, connecting patient diagnosis to treatment via mechanism-based dynamical system modeling and feedback control and allowing extrapolation from physiologic signals to biomarkers to novel drug candidates. As a predicate example, we focus on the role of data-driven and mechanistic models in neuroscience and the impact that merging these modeling approaches can have on general anesthesia.
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Affiliation(s)
- Jean-Marie Aerts
- Division Measure, Model & Manage Bioresponses (M3-BIORES), Department of Biosystems, KU Leuven, Leuven, Belgium B-3001
| | - Wassim M Haddad
- School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0150
| | - Gary An
- Department of Surgery, University of Chicago Medicine, Chicago, IL 60637
| | - Yoram Vodovotz
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213; Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219.
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Abstract
In mammals and birds, all oxygen used (VO2) must pass through the lungs; hence, some degree of coupling between VO2 and pulmonary ventilation (VE) is highly predictable. Nevertheless, VE is also involved with CO2 elimination, a task that is often in conflict with the convection of O2. In hot or cold conditions, the relationship between VE and VO2 includes the participation of the respiratory apparatus to the control of body temperature and water balance. Some compromise among these tasks is achieved through changes in breathing pattern, uncoupling changes in alveolar ventilation from VE. This article examines primarily the relationship between VE and VO2 under thermal stimuli. In the process, it considers how the relationship is influenced by hypoxia, hypercapnia or changes in metabolic level. The shuffling of tasks in emergency situations illustrates that the constraints on VE-VO2 for the protection of blood gases have ample room for flexibility. However, when other priorities do not interfere with the primary goal of gas exchange, VE follows metabolic rate quite closely. The fact that arterial CO2 remains stable when metabolism is changed by the most diverse circumstances (moderate exercise, cold, cold and exercise combined, variations in body size, caloric intake, age, time of the day, hormones, drugs, etc.) makes it unlikely that VE and metabolism are controlled in parallel by the condition responsible for the metabolic change. Rather, some observations support the view that the gaseous component of metabolic rate, probably CO2, may provide the link between the metabolic level and VE.
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26
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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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E. coli endotoxin modulates the expression of Sirtuin proteins in PBMC in humans. Mediators Inflamm 2013; 2013:876943. [PMID: 24347837 PMCID: PMC3852091 DOI: 10.1155/2013/876943] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/22/2013] [Indexed: 12/15/2022] Open
Abstract
Background. Sirtuin (SIRT) proteins are class I histone deacetylases displaying gene regulatory functions in inflammatory, cancer, and metabolic diseases. These SIRT actions involve the nuclear factor κB and its inhibitor IκB pathway. However, the regulation of SIRT in vivo is still unclear. Material and Methods. In a human endotoxemia model, 20 healthy male subjects received an intravenous bolus of 2 ng/kg body weight Escherichia coli endotoxin (LPS). SIRT expression was investigated in peripheral blood mononuclear cells (PBMC) with qPCR and Western blot before and 3 hours, 6 hours, and 24 hours after LPS challenge. Additionally, SIRT regulation was studied in vitro in cultivated PBMC after incubation with 20 ng/mL LPS. Results. A downregulation by >40% of SIRT1 mRNA was detectable 3 hours after LPS and of SIRT3 mRNA 6 hours after LPS. SIRT3, IκBα, and IκB-β protein expressions were decreased 3 and 6 hours after LPS. SIRT2 mRNA or protein expression did not change following LPS. These findings were consistent in vitro and associated with augmented phosphorylation of IκB-β. Discussion. In this E. coli endotoxemia model, SIRT1 and SIRT3 mRNA expressions in PBMC in humans were reduced after LPS challenge. This suggests that SIRT may represent an inflammatory target protein in vivo.
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Gutierrez G, Das A, Ballarino G, Beyzaei-Arani A, Türkan H, Wulf-Gutierrez M, Rider K, Kaya H, Amdur R. Decreased respiratory rate variability during mechanical ventilation is associated with increased mortality. Intensive Care Med 2013; 39:1359-67. [PMID: 23743521 DOI: 10.1007/s00134-013-2937-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 04/14/2013] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Patients on ventilatory support often experience significant changes in respiratory rate. Our aim was to determine the possible association between respiratory rate variability (RRV) and outcomes in these patients. DESIGN A longitudinal, prospective, observational study of patients mechanically ventilated for at least 12 h performed in a medical-surgical intensive care unit. Patients were enrolled within 24 h of the initiation of ventilatory support. We measured airway signals continuously for the duration of ventilatory support and calculated expiratory flow frequency spectra at 2.5-min intervals. We assessed RRV using the amplitude ratio of the flow spectrum's first harmonic to the zero frequency component. Measures of the amplitude ratio were averaged over the total monitored time. Patients with time-averaged amplitude ratios <40 % were classified as high RRV and those ≥40 % as low RRV. All-cause mortality rates were assessed at 28 and 180 days from enrollment with a Cox proportional hazards model adjusted for disease acuity by the simplified acute physiology score II. RESULTS We enrolled 178 patients, of whom 47 had high RRV and 131 low RRV. Both groups had similar disease acuity upon enrollment. The 28- and 180-day mortality rates were greater for low RRV patients with hazard ratios of 4.81 (95 % CI 1.85-12.65, p = 0.001) and 2.26 (95 % CI 1.21-4.20, p = 0.01), respectively. Independent predictors of 28-day mortality were low RRV, i.v. vasopressin, and SAPS II. CONCLUSIONS Decreased RRV during ventilatory support is associated with increased mortality. The mechanisms responsible for this finding remain to be determined.
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Affiliation(s)
- Guillermo Gutierrez
- Pulmonary, Critical Care and Sleep Medicine Division, The George Washington University MFA, 2150 Pennsylvania Ave, NW, Washington DC, 20037, USA.
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Abstract
Sepsis is a clinical entity in which complex inflammatory and physiological processes are mobilized, not only across a range of cellular and molecular interactions, but also in clinically relevant physiological signals accessible at the bedside. There is a need for a mechanistic understanding that links the clinical phenomenon of physiologic variability with the underlying patterns of the biology of inflammation, and we assert that this can be facilitated through the use of dynamic mathematical and computational modeling. An iterative approach of laboratory experimentation and mathematical/computational modeling has the potential to integrate cellular biology, physiology, control theory, and systems engineering across biological scales, yielding insights into the control structures that govern mechanisms by which phenomena, detected as biological patterns, are produced. This approach can represent hypotheses in the formal language of mathematics and computation, and link behaviors that cross scales and domains, thereby offering the opportunity to better explain, diagnose, and intervene in the care of the septic patient.
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Affiliation(s)
- Gary An
- Department of Surgery, University of Chicago, Chicago, IL 60637
- Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219
| | - Rami A. Namas
- Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213
| | - Yoram Vodovotz
- Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213
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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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Sepsis: Something old, something new, and a systems view. J Crit Care 2011; 27:314.e1-11. [PMID: 21798705 DOI: 10.1016/j.jcrc.2011.05.025] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 05/08/2011] [Accepted: 05/19/2011] [Indexed: 01/01/2023]
Abstract
Sepsis is a clinical syndrome characterized by a multisystem response to a microbial pathogenic insult consisting of a mosaic of interconnected biochemical, cellular, and organ-organ interaction networks. A central thread that connects these responses is inflammation that, while attempting to defend the body and prevent further harm, causes further damage through the feed-forward, proinflammatory effects of damage-associated molecular pattern molecules. In this review, we address the epidemiology and current definitions of sepsis and focus specifically on the biologic cascades that comprise the inflammatory response to sepsis. We suggest that attempts to improve clinical outcomes by targeting specific components of this network have been unsuccessful due to the lack of an integrative, predictive, and individualized systems-based approach to define the time-varying, multidimensional state of the patient. We highlight the translational impact of computational modeling and other complex systems approaches as applied to sepsis, including in silico clinical trials, patient-specific models, and complexity-based assessments of physiology.
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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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Ting PC, Chou AH, Yang MW, Ho ACY, Chang CJ, Chang SC. Postoperative reintubation after planned extubation: A review of 137,866 general anesthetics from 2005 to 2007 in a Medical Center of Taiwan. ACTA ACUST UNITED AC 2010; 48:167-71. [DOI: 10.1016/j.aat.2010.12.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Revised: 08/25/2010] [Accepted: 08/30/2010] [Indexed: 12/20/2022]
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Aleksandrova NP, Danilova GA. Effect of intracerebroventricular injection of interleukin-1-beta on the ventilatory response to hyperoxic hypercapnia. Eur J Med Res 2010; 15 Suppl 2:3-6. [PMID: 21147611 PMCID: PMC4360325 DOI: 10.1186/2047-783x-15-s2-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Oxidative stress developed at several disease states and strenuous resistive breathing lead to the elevation of plasma and cerebral levels of proinflammatory cytokines. We hypothesized that the elevation of the cytokine level in body fluids would modulate breathing pattern and the ventilatory response to stimulation of central chemoreceptors by hypercapnia. - MATERIAL AND METHODS In experiments on anesthetized, tracheostomized, spontaneously breathing rats, the effects of intracerebroventricular injection of the human recombinant interleukin-1β (IL-1β) (0.5 μg/rat) on breathing were studied. - RESULTS During resting breathing IL-1β evoked a significant increase in minute ventilation and in mean inspiratory flow. Furthermore, injection of IL-1β into the cerebral-spinal fluid decreases the responses of ventilation, tidal volume, and of mean inspiratory flow to carbon dioxide. - CONCLUSIONS The elevation of a proinflammatory cytokine in cerebrospinal fluid intensifies ventilation by modulation of breathing pattern, but weakens the chemoreflex sensitivity to hypercapnia. The results suggest the participation of cytokines in the central control of breathing and in the mechanisms of central chemoreception.
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Affiliation(s)
- Nina P Aleksandrova
- Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia.
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Papaioannou VE, Chouvarda I, Maglaveras N, Dragoumanis C, Pneumatikos I. Changes of heart and respiratory rate dynamics during weaning from mechanical ventilation: a study of physiologic complexity in surgical critically ill patients. J Crit Care 2010; 26:262-72. [PMID: 20869842 DOI: 10.1016/j.jcrc.2010.07.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 07/18/2010] [Accepted: 07/20/2010] [Indexed: 10/19/2022]
Abstract
PURPOSE The aim of the study was to investigate heart rate (HR) and respiratory rate (RR) complexity in patients with weaning failure or success, using both linear and nonlinear techniques. MATERIALS AND METHODS Forty-two surgical patients were enrolled in the study. There were 24 who passed and 18 who failed a weaning trial. Signals were analyzed for 10 minutes during 2 phases: (1) pressure support (PS) ventilation (15-20 cm H(2)O) and (2) weaning trials with PS (5 cm H(2)O). Low- and high-frequency (LF, HF) components of HR signals, HR multiscale entropy (MSE), RR sample entropy, cross-sample entropy between cardiorespiratory signals, Poincaré plots, and α1 exponent were computed in all patients and during the 2 phases of PS. RESULTS Weaning failure patients exhibited significantly decreased RR sample entropy, LF, HF, and α1 exponent, compared with weaning success subjects (P < .001). Their changes were opposite between the 2 phases, except for MSE that increased between and within groups (P < .001). A new model including rapid shallow breathing index (RSBI), α1 exponent, RR, and cross-sample entropies predicted better weaning outcome compared with RSBI, airway occlusion pressure at 0.1 second (P(0.1)), and RSBI × P(0.1) (conventional model, R(2) = 0.887 vs 0.463; P < .001). Areas under the curve were 0.92 vs 0.86, respectively (P < .005). CONCLUSIONS We suggest that nonlinear analysis of cardiorespiratory dynamics has increased prognostic impact upon weaning outcome in surgical patients.
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Affiliation(s)
- Vasilios E Papaioannou
- Democritus University of Thrace, Alexandroupolis University Hospital, Department of Intensive Care Medicine, Dragana 68100, Greece.
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Lower interbreath interval complexity is associated with extubation failure in mechanically ventilated patients during spontaneous breathing trials. ACTA ACUST UNITED AC 2010; 68:1310-6. [PMID: 20539175 DOI: 10.1097/ta.0b013e3181da90db] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine whether lower complexity of interbreath interval as measured with nonlinear analysis techniques will identify patients who fail to separate from mechanical ventilation after 30-minute spontaneous breathing trials (SBTs). METHODS Respiratory waveforms from SBT of patients in surgical or burn intensive care units were recorded for later analysis. The decision to extubate was made by attending physician. Extubated patients were observed for 48 hours; during this time, reintubation or noninvasive positive pressure ventilation was considered as a failure. Analysis of waveform data by software was performed post hoc. Sample entropy (SampEn) and other nonlinear measures were 48 hours of extubation. RESULTS Thirty-two patients (24 burn, 8 trauma/surgical admissions; mean age, 40.2 +/- 16.9 years; 26 men and 6 women) who were intubated >24 hours were extubated after SBT. Twenty-four patients were successfully separated from mechanical ventilation and eight failed. Age, gender, and mechanism of injury did not influence outcome. SampEn calculated for the two groups presented in this study was different with the cohort that failed extubation having a lower mean value (1.35 +/- 0.39 vs. 1.87 +/- 0.27; p < 0.001). Other nonlinear metrics were moved in concert with SampEn. The stationarity in the respiratory signal was not different between groups. CONCLUSION In intubated patients, the interbreath interval in those who were successfully separated from mechanical ventilation was more irregular than those who failed, as measured by nonlinear techniques. When available at bedside, these metrics may be useful markers of pulmonary health and assist in clinical decision making.
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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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Casaseca-de-la-Higuera P, Simmross-Wattenberg F, Martin-Fernandez M, Alberola-Lopez C. A Multichannel Model-Based Methodology for Extubation Readiness Decision of Patients on Weaning Trials. IEEE Trans Biomed Eng 2009; 56:1849-63. [DOI: 10.1109/tbme.2009.2018295] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Engoren M, Courtney SE, Habib RH. Effect of weight and age on respiratory complexity in premature neonates. J Appl Physiol (1985) 2009; 106:766-73. [DOI: 10.1152/japplphysiol.90575.2008] [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
Very low-birth-weight premature infants often suffer from a variety of respiratory problems, including respiratory distress syndrome (RDS), hypopnea and periodic breathing, and apnea. These conditions are likely related to immaturity of the respiratory centers; yet how respiratory rhythms originating from these centers, including their complexity, relate to demographic measures of prematurity remains largely unknown. In 39 neonates with mild RDS (22 males, 28 ± 2 wk gestational age, 1,036 ± 234 g body wt), we derived the univariate association between complexity of two respiratory rhythms [respiratory rate (RR) and tidal volume (Vt)] and postmenstrual age, gestational age, postnatal age, and weight at time of study. RR and Vt rhythm complexities were assessed using approximate entropy, sample entropy, base scale entropy, and forbidden words entropy estimated for 300 consecutive breaths determined from respiratory inductance plethysmography, irrespective of breathing effort rate or amplitude, collected during sleep while the neonates were exposed to nasal continuous positive airway pressure (4–6 cmH2O). RR and Vt exhibited increased complexity with increased maturity, but only in terms of base scale entropy and forbidden words entropy, which are based on pattern matching, rather than approximate entropy and sample entropy, which are based on conditional probabilities. Specifically, RR complexity as measured by forbidden word entropy increased with increasing weight ( r = 0.502), postconceptional age ( r = 0.423), and gestational age ( r = 0.493). As measured by base scale entropy, RR complexity increased with increasing weight ( r = 0.488) and postconceptional age ( r = 0.390). Vt complexity, measured by base scale entropy, was greater with increased postnatal age ( r = 0.428). Our results indicate that respiratory rhythms become more complex with increasing levels of maturity, as indicated by increased weight and several age parameters. This emphasizes the importance of the later weeks of gestation in the maturation of respiratory centers in the brain and suggests a promising use of entropy measures in exploring respiratory maturation in infants.
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Abstract
In asthma, symptoms are the main reason for recourse to healthcare and are a fundamental parameter for the evaluation of asthma control. Currently, asthma is defined as a chronic inflammatory disease. Uncontrolled asthmatics have an increased number of eosinophils in induced sputum and an increased production of exhaled NO. Control by anti-inflammatory treatment is accompanied by a reduction in bronchial eosinophilia and exhaled NO. Asthma symptoms are the result of complex mechanisms and many factors modify their perception. Experimental data suggests that there is a relationship between the perception of symptoms and eosinophilic inflammation, and that inhaled corticoid therapy improves this perception. Although they are still not applicable in routine practice, follow-up strategies based on the evaluation of inflammation are thought to be more effective in reducing exacerbations than those usually recommended based on retrospective evaluation of symptoms and sequential analysis of respiratory function. Inhaled corticosteroid therapy is the reference maintenance therapy for persistent asthma and adjustment of anti-inflammatory treatment based on symptoms is an effective strategy to prevent exacerbations and reduce the total dose of inhaled corticosteroids. A French expert group has undertaken a study of the association between inflammation and asthma symptoms by carrying out a critical review of the international literature.
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Abstract
Achieving restorative sleep in the ICU remains a challenge for most patients. Various environmental and nonenvironmental factors affect sleep patterns in the ICU. This article discusses the effects and relative importance of these factors on sleep patterns in the critical care setting. In addition, the implications of sleep pattern alteration on human physiology and homeostatic mechanisms are considered.
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Sayk F, Vietheer A, Schaaf B, Wellhoener P, Weitz G, Lehnert H, Dodt C. Endotoxemia causes central downregulation of sympathetic vasomotor tone in healthy humans. Am J Physiol Regul Integr Comp Physiol 2008; 295:R891-8. [DOI: 10.1152/ajpregu.90444.2008] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Experimental endotoxemia as a model of the initial septic response affects the autonomic nervous system with profound cardiovascular sequelae. Whether the postsynaptic sympathoneural activity to the muscle vascular bed is altered in the early septic phase remains to be determined. The present study aimed to elucidate the early effects of LPS on muscle sympathetic nerve activity (MSNA) and cardiovascular regulation in healthy humans. Young, healthy volunteers randomly received either an LPS bolus (4 ng/kg body wt, n = 11) or placebo (saline; n = 7). Experimental baroreflex assessment (baseline measurements followed by infusion of vasoactive drugs nitroprusside/phenylephrine) was done prior to and 90 min following LPS or placebo challenge. MSNA, heart rate, blood pressure, and blood levels of catecholamines, TNF-α and IL-6 were measured sequentially. Endotoxin but not placebo-induced flu-like symptoms and elevated cytokine levels. In contrast to placebo, LPS significantly suppressed MSNA burst frequency 90 min after injection [mean ± SE: 12.1 ± 2.9 vs. 27.5 ± 3.3 burst/min (post- vs. pre-LPS); P < 0.005] but increased heart rate [78.4 ± 3.1 vs. 60.6 ± 2.0 beats/min (post- vs. pre-LPS); P < 0.001]. Baseline blood pressure was not altered, but baroreflex testing demonstrated a blunted MSNA response and uncoupling of heart rate modulation to blood pressure changes in the endotoxin group. We conclude that endotoxin challenge in healthy humans has rapid suppressive effects on postsynaptic sympathetic nerve activity to the muscle vascular bed and alters baroreflex function which may contribute to the untoward cardiovascular effects of sepsis.
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Physiological and pathophysiological roles of extracellular ATP in chemosensory control of breathing. Biochem Soc Trans 2008; 35:1264-8. [PMID: 17956326 DOI: 10.1042/bst0351264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The purine nucleotide ATP mediates several distinct forms of sensory transduction in both the peripheral and central nervous systems. These processes share common mechanisms that involve the release of ATP to activate ionotropic P2X and/or metabotropic P2Y receptors. Extracellular ATP signalling plays an important role in ventilatory control, mediating both peripheral and central chemosensory transduction to changes in arterial levels of oxygen and carbon dioxide. New data also suggest that extracellular ATP may play an important role in mediating certain neurophysiological responses to systemic inflammation. Here, we propose the novel concept that both peripheral and central neurophysiological effects of ATP may contribute to alterations in ventilatory control during inflammatory pathophysiological states.
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Jubran A, Tobin MJ. Noninvasive Respiratory Monitoring. Crit Care Med 2008. [DOI: 10.1016/b978-032304841-5.50015-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ladino J, Bancalari E, Suguihara C. Ventilatory response to hypoxia during endotoxemia in young rats: role of nitric oxide. Pediatr Res 2007; 62:134-8. [PMID: 17597656 DOI: 10.1203/pdr.0b013e318098721a] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Administration of Escherichia coli endotoxin attenuates the ventilatory response to hypoxia (VRH) in newborn piglets, but the mechanisms responsible for this depression are not clearly understood. Nitric oxide (NO) production increases during sepsis and elevated NO levels can inhibit carotid body function. The role of endothelial NO on the VRH during endotoxemia was evaluated in 26 young rats. Minute ventilation (VE) and oxygen consumption (VO2) were measured in room air (RA) and during 30 min of hypoxia (10% O2) before and after E. coli endotoxin administration. During endotoxemia, animals received placebo (PL, n = 8); a nonselective nitric oxide synthase (NOS) inhibitor (NG-nitro-L-arginine methyl ester, L-NAME, n = 9), or a neuronal NOS (nNOS) inhibitor (7-nitroindazole, 7-NI, n = 9). During endotoxemia, a larger increase in VE was observed only during the first min of hypoxia in the L-NAME group when compared with PL or 7-NI (p < 0.001). VRH was similar in the PL and 7-NI groups. A larger decrease in VO2 at 30 min of hypoxia was observed in L-NAME and 7-NI groups when compared with PL (p < 0.03). These data demonstrate that the attenuation of the early VRH during endotoxemia is in part mediated by an inhibitory effect of endothelial NO on the respiratory control mechanisms.
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Affiliation(s)
- John Ladino
- Department of Pediatrics, Division of Neonatology, Neonatal Developmental Biology Laboratory, Batchelor Children's Research Institute, University of Miami Miller School of Medicine, Miami, Florida 33101, USA
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Wysocki M, Cracco C, Teixeira A, Mercat A, Diehl JL, Lefort Y, Derenne JP, Similowski T. Reduced breathing variability as a predictor of unsuccessful patient separation from mechanical ventilation. Crit Care Med 2006; 34:2076-83. [PMID: 16755257 DOI: 10.1097/01.ccm.0000227175.83575.e9] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To compare descriptors of the breath-to-breath respiratory variability during a 60-min spontaneous breathing trial in patients successfully and unsuccessfully separated from the ventilator and the endotracheal tube and to assess the usefulness of these predictors in discriminating these two categories of patients. DESIGN Prospective observational study. SETTING Four general intensive care units in university hospitals. PATIENTS A total of 51 consecutive patients mechanically ventilated for >24 hrs. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Tidal volume, respiratory period, inspiratory time, expiratory time, mean inspiratory flow (tidal volume/inspiratory time), and duty cycle (inspiratory time/respiratory period) were obtained from the flow signal. Breath-by-breath variability was expressed in terms of their coefficients of variation (CV), the number of breaths among which a significant correlation was found (lag), and the autocorrelation coefficient between one breath and the following one. Five patients were excluded because of nonstationarity of the data, leaving 46 cases for analysis. Between-group comparison was conducted with the Mann-Whitney test, and a nonparametric classification and regression tree was used to identify variables discriminating "success" (n = 32) and "failure" patients (n = 14). All coefficients of variation were significantly higher in success patients, who also exhibited significantly less respiratory autocorrelation (shorter "short memory"). The classification and regression tree analysis allocated all success patients to a group defined by a coefficient of variation of tidal volume/inspiratory time of > or =19% and a coefficient of variation of inspiratory time/respiratory period of > or =10% that did not contain any failure patient. All failure patients belonged to a group with coefficient of variation of tidal volume/inspiratory time of <19%, a lag tidal volume of > or =11, and that contained no success patient. CONCLUSIONS In intensive care unit patients undergoing a spontaneous breathing trial, breathing variability is greater in patients successfully separated from the ventilator and the endotracheal tube. Variability indices are sufficient to separate success from failure cases.
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Affiliation(s)
- Marc Wysocki
- UPRES EA 2397, Université Paris VI Pierre et Marie Curie, Paris, France
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Casaseca-de-la-Higuera P, Martín-Fernández M, Alberola-López C. Weaning From Mechanical Ventilation: A Retrospective Analysis Leading to a Multimodal Perspective. IEEE Trans Biomed Eng 2006; 53:1330-45. [PMID: 16830937 DOI: 10.1109/tbme.2006.873695] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Practitioners' decision for mechanical aid discontinuation is a challenging task that involves a complete knowledge of a great number of clinical parameters, as well as its evolution in time. Recently, an increasing interest on respiratory pattern variability as an extubation readiness indicator has appeared. Reliable assessment of this variability involves a set of signal processing and pattern recognition techniques. This paper presents a suitability analysis of different methods used for breathing pattern complexity assessment. The contribution of this analysis is threefold: 1) to serve as a review of the state of the art on the so-called weaning problem from a signal processing point of view; 2) to provide insight into the applied processing techniques and how they fit into the problem; 3) to propose additional methods and further processing in order to improve breathing pattern regularity assessment and weaning readiness decision. Results on experimental data show that sample entropy outperforms other complexity assessment methods and that multidimensional classification does improve weaning prediction. However, the obtained performance may be objectionable for real clinical practice, a fact that paves the way for a multimodal signal processing framework, including additional high-quality signals and more reliable statistical methods.
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Affiliation(s)
- Pablo Casaseca-de-la-Higuera
- Laboratory of Image Processing, E.T.S. Ingenieros de Telecomunicación, University of Valladolid, 47011 Valladolid, Spain.
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Talwar S, Munson PJ, Barb J, Fiuza C, Cintron AP, Logun C, Tropea M, Khan S, Reda D, Shelhamer JH, Danner RL, Suffredini AF. Gene expression profiles of peripheral blood leukocytes after endotoxin challenge in humans. Physiol Genomics 2006; 25:203-15. [PMID: 16403844 PMCID: PMC5560445 DOI: 10.1152/physiolgenomics.00192.2005] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
To define gene expression profiles that occur during the initial activation of human innate immunity, we administered intravenous endotoxin (n = 8) or saline (n = 4) to healthy subjects and hybridized RNA from blood mononuclear cells (0, 0.5, 6, 24, 168 h) or whole blood (0, 3, 6, 24, 168 h) to oligonucleotide probe arrays. The greatest change in mononuclear cell gene expression occurred at 6 h (439 induced and 428 repressed genes, 1% false discovery rate, and 50% fold change) including increased expression of genes associated with pathogen recognition molecules and signaling cascades linked to receptors associated with cell mobility and activation. Induced defense response genes included cytokines, chemokines, and their respective receptors, acute-phase transcription factors, proteases, arachidonate metabolites, and oxidases. Repressed defense response genes included those associated with co-stimulatory molecules, T and cytotoxic lymphocytes, natural killer (NK) cells, and protein synthesis. Gene expression profiles of whole blood had similar biological themes. Over 100 genes not typically associated with acute inflammation were differentially regulated after endotoxin. By 24 h, gene expression had returned to baseline values. Thus the inflammatory response of circulating leukocytes to endotoxin in humans is characterized by a rapid amplification and subsidence of gene expression. These results indicate that a single intravascular exposure to endotoxin produces a large but temporally short perturbation of the blood transcriptome.
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Affiliation(s)
- Shefali Talwar
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1662, USA
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Anel R, Kumar A. Human endotoxemia and human sepsis: limits to the model. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2005; 9:151-2. [PMID: 15774069 PMCID: PMC1175943 DOI: 10.1186/cc3501] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Sepsis remains the most common cause of death in intensive care units of the developed world. Accurate models of this disease syndrome are crucial for to the understanding of the complex pathophysiology of this disorder. The administration of a small dose of lipopolysaccharide to healthy volunteers is one such model of spontaneous human sepsis. Although this human endotoxemia model appears to be reasonably effective in mimicking early biochemical, metabolic, hematologic and cardiovascular septic responses in septic shock, the ability to mimic other aspects of human sepsis is open to question. The current study demonstrates that human experimental endotoxemia fails to generate evidence of increased vascular permeability within the relatively short time frame of the study.
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Affiliation(s)
- Ramon Anel
- Assistant Professor, Section of Critical Care Medicine, Section of Nephrology, University of North Dakota, Grand Forks, North Dakota, USA
| | - Anand Kumar
- Associate Professor, Section of Critical Care Medicine, Section of Infectious Diseases, University of Manitoba, Winnipeg, Canada, and University of Medicine and Dentistry, UMDNJ, Camden, New Jersey, USA
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