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Junhasavasdikul D, Kasemchaiyanun A, Tassaneyasin T, Petnak T, Bezerra FS, Mellado-Artigas R, Chen L, Sutherasan Y, Theerawit P, Brochard L. Expiratory flow limitation during mechanical ventilation: real-time detection and physiological subtypes. Crit Care 2024; 28:171. [PMID: 38773629 PMCID: PMC11106966 DOI: 10.1186/s13054-024-04953-9] [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: 03/04/2024] [Accepted: 05/13/2024] [Indexed: 05/24/2024] Open
Abstract
BACKGROUND Tidal expiratory flow limitation (EFLT) complicates the delivery of mechanical ventilation but is only diagnosed by performing specific manoeuvres. Instantaneous analysis of expiratory resistance (Rex) can be an alternative way to detect EFLT without changing ventilatory settings. This study aimed to determine the agreement of EFLT detection by Rex analysis and the PEEP reduction manoeuvre using contingency table and agreement coefficient. The patterns of Rex were explored. METHODS Medical patients ≥ 15-year-old receiving mechanical ventilation underwent a PEEP reduction manoeuvre from 5 cmH2O to zero for EFLT detection. Waveforms were recorded and analyzed off-line. The instantaneous Rex was calculated and was plotted against the volume axis, overlapped by the flow-volume loop for inspection. Lung mechanics, characteristics of the patients, and clinical outcomes were collected. The result of the Rex method was validated using a separate independent dataset. RESULTS 339 patients initially enrolled and underwent a PEEP reduction. The prevalence of EFLT was 16.5%. EFLT patients had higher adjusted hospital mortality than non-EFLT cases. The Rex method showed 20% prevalence of EFLT and the result was 90.3% in agreement with PEEP reduction manoeuvre. In the validation dataset, the Rex method had resulted in 91.4% agreement. Three patterns of Rex were identified: no EFLT, early EFLT, associated with airway disease, and late EFLT, associated with non-airway diseases, including obesity. In early EFLT, external PEEP was less likely to eliminate EFLT. CONCLUSIONS The Rex method shows an excellent agreement with the PEEP reduction manoeuvre and allows real-time detection of EFLT. Two subtypes of EFLT are identified by Rex analysis. TRIAL REGISTRATION Clinical trial registered with www.thaiclinicaltrials.org (TCTR20190318003). The registration date was on 18 March 2019, and the first subject enrollment was performed on 26 March 2019.
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Affiliation(s)
- Detajin Junhasavasdikul
- Division of Pulmonary and Pulmonary Critical Care, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama 6 Rd. Rajthevi, Bangkok, Thailand.
| | - Akarawut Kasemchaiyanun
- Division of Pulmonary and Pulmonary Critical Care, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama 6 Rd. Rajthevi, Bangkok, Thailand
- Division of Critical Care, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Tanakorn Tassaneyasin
- Division of Pulmonary and Pulmonary Critical Care, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama 6 Rd. Rajthevi, Bangkok, Thailand
| | - Tananchai Petnak
- Division of Pulmonary and Pulmonary Critical Care, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama 6 Rd. Rajthevi, Bangkok, Thailand
| | - Frank Silva Bezerra
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
- Laboratory of Experimental Pathophysiology, Department of Biological Sciences and Center of Research in Biological Sciences, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | - Ricard Mellado-Artigas
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
- Surgical Intensive Care Unit, Department of Anesthesia, Hospital Clinic, Barcelona, Spain
| | - Lu Chen
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Yuda Sutherasan
- Division of Pulmonary and Pulmonary Critical Care, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama 6 Rd. Rajthevi, Bangkok, Thailand
| | - Pongdhep Theerawit
- Division of Critical Care, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Laurent Brochard
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
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2
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Selickman J, Marini JJ. Chest wall loading in the ICU: pushes, weights, and positions. Ann Intensive Care 2022; 12:103. [PMID: 36346532 PMCID: PMC9640797 DOI: 10.1186/s13613-022-01076-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/20/2022] [Indexed: 11/11/2022] Open
Abstract
Clinicians monitor mechanical ventilatory support using airway pressures—primarily the plateau and driving pressure, which are considered by many to determine the safety of the applied tidal volume. These airway pressures are influenced not only by the ventilator prescription, but also by the mechanical properties of the respiratory system, which consists of the series-coupled lung and chest wall. Actively limiting chest wall expansion through external compression of the rib cage or abdomen is seldom performed in the ICU. Recent literature describing the respiratory mechanics of patients with late-stage, unresolving, ARDS, however, has raised awareness of the potential diagnostic (and perhaps therapeutic) value of this unfamiliar and somewhat counterintuitive practice. In these patients, interventions that reduce resting lung volume, such as loading the chest wall through application of external weights or manual pressure, or placing the torso in a more horizontal position, have unexpectedly improved tidal compliance of the lung and integrated respiratory system by reducing previously undetected end-tidal hyperinflation. In this interpretive review, we first describe underappreciated lung and chest wall interactions that are clinically relevant to both normal individuals and to the acutely ill who receive ventilatory support. We then apply these physiologic principles, in addition to published clinical observation, to illustrate the utility of chest wall modification for the purposes of detecting end-tidal hyperinflation in everyday practice.
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Affiliation(s)
- John Selickman
- grid.17635.360000000419368657Department of Pulmonary and Critical Care Medicine, University of Minnesota, Minneapolis, MN USA ,grid.415858.50000 0001 0087 6510Department of Critical Care Medicine, Regions Hospital, MS 11203B, 640 Jackson St., St. Paul, MN 55101-2595 USA
| | - John J. Marini
- grid.17635.360000000419368657Department of Pulmonary and Critical Care Medicine, University of Minnesota, Minneapolis, MN USA ,grid.415858.50000 0001 0087 6510Department of Critical Care Medicine, Regions Hospital, MS 11203B, 640 Jackson St., St. Paul, MN 55101-2595 USA
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3
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Rezoagli E, Laffey JG, Bellani G. Monitoring Lung Injury Severity and Ventilation Intensity during Mechanical Ventilation. Semin Respir Crit Care Med 2022; 43:346-368. [PMID: 35896391 DOI: 10.1055/s-0042-1748917] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Acute respiratory distress syndrome (ARDS) is a severe form of respiratory failure burden by high hospital mortality. No specific pharmacologic treatment is currently available and its ventilatory management is a key strategy to allow reparative and regenerative lung tissue processes. Unfortunately, a poor management of mechanical ventilation can induce ventilation induced lung injury (VILI) caused by physical and biological forces which are at play. Different parameters have been described over the years to assess lung injury severity and facilitate optimization of mechanical ventilation. Indices of lung injury severity include variables related to gas exchange abnormalities, ventilatory setting and respiratory mechanics, ventilation intensity, and the presence of lung hyperinflation versus derecruitment. Recently, specific indexes have been proposed to quantify the stress and the strain released over time using more comprehensive algorithms of calculation such as the mechanical power, and the interaction between driving pressure (DP) and respiratory rate (RR) in the novel DP multiplied by four plus RR [(4 × DP) + RR] index. These new parameters introduce the concept of ventilation intensity as contributing factor of VILI. Ventilation intensity should be taken into account to optimize protective mechanical ventilation strategies, with the aim to reduce intensity to the lowest level required to maintain gas exchange to reduce the potential for VILI. This is further gaining relevance in the current era of phenotyping and enrichment strategies in ARDS.
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Affiliation(s)
- Emanuele Rezoagli
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,Department of Emergency and Intensive Care, San Gerardo University Hospital, Monza, Italy
| | - John G Laffey
- School of Medicine, National University of Ireland, Galway, Ireland.,Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Saolta University Hospital Group, Galway, Ireland.,Lung Biology Group, Regenerative Medicine Institute (REMEDI) at CÚRAM Centre for Research in Medical Devices, National University of Ireland Galway, Galway, Ireland
| | - Giacomo Bellani
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,Department of Emergency and Intensive Care, San Gerardo University Hospital, Monza, Italy
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4
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Raidal SL, Catanchin CSM, Burgmeestre L, Quinn CT. Bi-Level Positive Airway Pressure for Non-invasive Respiratory Support of Foals. Front Vet Sci 2021; 8:741720. [PMID: 34660771 PMCID: PMC8511517 DOI: 10.3389/fvets.2021.741720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/27/2021] [Indexed: 11/25/2022] Open
Abstract
Respiratory insufficiency and pulmonary health are important considerations in equine neonatal care. As the majority of foals are bred for athletic pursuits, strategies for respiratory support of compromised foals are of particular importance. The administration of supplementary oxygen is readily implemented in equine practice settings, but does not address respiratory insufficiency due to inadequate ventilation and is no longer considered optimal care for hypoxia in critical care settings. Non-invasive ventilatory strategies including continuous or bi-level positive airway pressure are effective in human and veterinary studies, and may offer improved respiratory support in equine clinical practice. The current study was conducted to investigate the use of a commercial bi-level positive airway pressure (BiPAP) ventilator, designed for home care of people with obstructive respiratory conditions, for respiratory support of healthy foals with pharmacologically induced respiratory insufficiency. A two sequence (administration of supplementary oxygen with, or without, BiPAP), two phase, cross-over experimental design was used in a prospective study with six foals. Gas exchange and mechanics of breathing (increased tidal volume, decreased respiratory rate and increased peak inspiratory flow) were improved during BiPAP relative to administration of supplementary oxygen alone or prior studies using continuous positive airway pressure, but modest hypercapnia was observed. Clinical observations, pulse oximetry and monitoring of expired carbon dioxide was of limited benefit in identification of foals responding inappropriately to BiPAP, and improved methods to assess and monitor respiratory function are required in foals.
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Affiliation(s)
- Sharanne L Raidal
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
| | | | - Lexi Burgmeestre
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Chris T Quinn
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
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5
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Fogagnolo A, Montanaro F, Al-Husinat L, Turrini C, Rauseo M, Mirabella L, Ragazzi R, Ottaviani I, Cinnella G, Volta CA, Spadaro S. Management of Intraoperative Mechanical Ventilation to Prevent Postoperative Complications after General Anesthesia: A Narrative Review. J Clin Med 2021; 10:jcm10122656. [PMID: 34208699 PMCID: PMC8234365 DOI: 10.3390/jcm10122656] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/09/2021] [Accepted: 06/15/2021] [Indexed: 01/02/2023] Open
Abstract
Mechanical ventilation (MV) is still necessary in many surgical procedures; nonetheless, intraoperative MV is not free from harmful effects. Protective ventilation strategies, which include the combination of low tidal volume and adequate positive end expiratory pressure (PEEP) levels, are usually adopted to minimize the ventilation-induced lung injury and to avoid post-operative pulmonary complications (PPCs). Even so, volutrauma and atelectrauma may co-exist at different levels of tidal volume and PEEP, and therefore, the physiological response to the MV settings should be monitored in each patient. A personalized perioperative approach is gaining relevance in the field of intraoperative MV; in particular, many efforts have been made to individualize PEEP, giving more emphasis on physiological and functional status to the whole body. In this review, we summarized the latest findings about the optimization of PEEP and intraoperative MV in different surgical settings. Starting from a physiological point of view, we described how to approach the individualized MV and monitor the effects of MV on lung function.
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Affiliation(s)
- Alberto Fogagnolo
- Department of Translation Medicine and for Romagna, Section of Anesthesia and Intensive Care, University of Ferrara, 44121 Ferrara, Italy; (F.M.); (C.T.); (R.R.); (I.O.); (C.A.V.); (S.S.)
- Correspondence:
| | - Federica Montanaro
- Department of Translation Medicine and for Romagna, Section of Anesthesia and Intensive Care, University of Ferrara, 44121 Ferrara, Italy; (F.M.); (C.T.); (R.R.); (I.O.); (C.A.V.); (S.S.)
| | - Lou’i Al-Husinat
- Department of Clinical Sciences, Faculty of Medicine, Yarmouk University, Irbid 21163, Jordan;
| | - Cecilia Turrini
- Department of Translation Medicine and for Romagna, Section of Anesthesia and Intensive Care, University of Ferrara, 44121 Ferrara, Italy; (F.M.); (C.T.); (R.R.); (I.O.); (C.A.V.); (S.S.)
| | - Michela Rauseo
- Department of Anesthesia and Intensive Care, University of Foggia, 71122 Foggia, Italy; (M.R.); (L.M.); (G.C.)
| | - Lucia Mirabella
- Department of Anesthesia and Intensive Care, University of Foggia, 71122 Foggia, Italy; (M.R.); (L.M.); (G.C.)
| | - Riccardo Ragazzi
- Department of Translation Medicine and for Romagna, Section of Anesthesia and Intensive Care, University of Ferrara, 44121 Ferrara, Italy; (F.M.); (C.T.); (R.R.); (I.O.); (C.A.V.); (S.S.)
| | - Irene Ottaviani
- Department of Translation Medicine and for Romagna, Section of Anesthesia and Intensive Care, University of Ferrara, 44121 Ferrara, Italy; (F.M.); (C.T.); (R.R.); (I.O.); (C.A.V.); (S.S.)
| | - Gilda Cinnella
- Department of Anesthesia and Intensive Care, University of Foggia, 71122 Foggia, Italy; (M.R.); (L.M.); (G.C.)
| | - Carlo Alberto Volta
- Department of Translation Medicine and for Romagna, Section of Anesthesia and Intensive Care, University of Ferrara, 44121 Ferrara, Italy; (F.M.); (C.T.); (R.R.); (I.O.); (C.A.V.); (S.S.)
| | - Savino Spadaro
- Department of Translation Medicine and for Romagna, Section of Anesthesia and Intensive Care, University of Ferrara, 44121 Ferrara, Italy; (F.M.); (C.T.); (R.R.); (I.O.); (C.A.V.); (S.S.)
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6
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Gaver DP, Nieman GF, Gatto LA, Cereda M, Habashi NM, Bates JHT. The POOR Get POORer: A Hypothesis for the Pathogenesis of Ventilator-induced Lung Injury. Am J Respir Crit Care Med 2020; 202:1081-1087. [PMID: 33054329 DOI: 10.1164/rccm.202002-0453cp] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Protective ventilation strategies for the injured lung currently revolve around the use of low Vt, ostensibly to avoid volutrauma, together with positive end-expiratory pressure to increase the fraction of open lung and reduce atelectrauma. Protective ventilation is currently applied in a one-size-fits-all manner, and although this practical approach has reduced acute respiratory distress syndrome deaths, mortality is still high and improvements are at a standstill. Furthermore, how to minimize ventilator-induced lung injury (VILI) for any given lung remains controversial and poorly understood. Here we present a hypothesis of VILI pathogenesis that potentially serves as a basis upon which minimally injurious ventilation strategies might be developed. This hypothesis is based on evidence demonstrating that VILI begins in isolated lung regions manifesting a Permeability-Originated Obstruction Response (POOR) in which alveolar leak leads to surfactant dysfunction and increases local tissue stresses. VILI progresses topographically outward from these regions in a POOR-get-POORer fashion unless steps are taken to interrupt it. We propose that interrupting the POOR-get-POORer progression of lung injury relies on two principles: 1) open the lung to minimize the presence of heterogeneity-induced stress concentrators that are focused around the regions of atelectasis, and 2) ventilate in a patient-dependent manner that minimizes the number of lung units that close during each expiration so that they are not forced to rerecruit during the subsequent inspiration. These principles appear to be borne out in both patient and animal studies in which expiration is terminated before derecruitment of lung units has enough time to occur.
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Affiliation(s)
- Donald P Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, New York
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, Syracuse, New York
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care and.,Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nader M Habashi
- R Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, Maryland; and
| | - Jason H T Bates
- Department of Medicine, University of Vermont, Burlington, Vermont
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7
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Turbil E, Terzi N, Cour M, Argaud L, Einav S, Guérin C. Positive end-expiratory pressure-induced recruited lung volume measured by volume-pressure curves in acute respiratory distress syndrome: a physiologic systematic review and meta-analysis. Intensive Care Med 2020; 46:2212-2225. [PMID: 32915255 PMCID: PMC7484614 DOI: 10.1007/s00134-020-06226-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/20/2020] [Indexed: 12/26/2022]
Abstract
PURPOSE Recruitment of lung volume is often cited as the reason for using positive end-expiratory pressure (PEEP) in acute respiratory distress syndrome (ARDS) patients. We performed a systematic review on PEEP-induced recruited lung volume measured from inspiratory volume-pressure (VP) curves in ARDS patients to assess the prevalence of patients with PEEP-induced recruited lung volume and the mortality in recruiters and non-recruiters. METHODS We conducted a systematic search of PubMed to identify studies including ARDS patients in which the intervention of an increase in PEEP was accompanied by measurement of the recruited volume (Vrec increase versus no increase) using the VP curve in order to assess the relation between Vrec and mortality at ICU discharge. We first analysed the pooled data from the papers identified and then analysed individual patient level data received from the authors via personal contact. The risk of bias of the included papers was assessed using the quality in prognosis studies tool and the certainty of the evidence regarding the relationship of mortality to Vrec by the GRADE approach. Recruiters were defined as patients with a Vrec > 150 ml. A random effects model was used for the pooled data. Multivariable logistic regression analysis was used for individual patient data. RESULTS We identified 16 papers with a total of 308 patients for the pooled data meta-analysis and 14 papers with a total of 384 patients for the individual data analysis. The quality of the articles was moderate. In the pooled data, the prevalence of recruiters was 74% and the mortality was not significantly different between recruiters and non-recruiters (relative risk 1.20 [95% confidence intervals 0.88-1.63]). The certainty of the evidence regarding this association was very low and publication bias evident. In the individual data, the prevalence of recruiters was 70%. In the multivariable logistic regression, Vrec was not associated with mortality but Simplified Acute Physiology Score II and driving pressure at PEEP of 5 cmH2O were. CONCLUSION After a PEEP increment, most patients are recruiters. Vrec was not associated with ICU mortality. The presence of similar findings in the individual patient level analysis and the driving pressure at PEEP of 5 cmH2O was associated with mortality as previously reported validate our findings. Publication bias and the lack of prospective studies suggest more research is required.
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Affiliation(s)
- Emanuele Turbil
- Department of Anesthesia and Critical Care, University of Sassari, Sassari, Italy
| | - Nicolas Terzi
- Médecine Intensive-Réanimation, CHU Grenoble-Alpes, Grenoble, France.,University of Grenoble-Alpes, Grenoble, France
| | - Martin Cour
- Médecine Intensive-Réanimation, Groupement Hospitalier Centre, Hôpital Edouard Herriot, 5 Place d'Arsonval, 69003, Lyon, France.,Université de Lyon, Faculté de Médecine Lyon-Est, Lyon, France
| | - Laurent Argaud
- Médecine Intensive-Réanimation, Groupement Hospitalier Centre, Hôpital Edouard Herriot, 5 Place d'Arsonval, 69003, Lyon, France.,Université de Lyon, Faculté de Médecine Lyon-Est, Lyon, France
| | | | - Claude Guérin
- Médecine Intensive-Réanimation, Groupement Hospitalier Centre, Hôpital Edouard Herriot, 5 Place d'Arsonval, 69003, Lyon, France. .,Université de Lyon, Faculté de Médecine Lyon-Est, Lyon, France. .,Institut Mondor de Recherches Biomédicales, INSERM 955, CNRS ERL 7000, Créteil, France.
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8
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Pellegrini M, Gudmundsson M, Bencze R, Segelsjö M, Freden F, Rylander C, Hedenstierna G, Larsson AS, Perchiazzi G. Expiratory Resistances Prevent Expiratory Diaphragm Contraction, Flow Limitation, and Lung Collapse. Am J Respir Crit Care Med 2020; 201:1218-1229. [PMID: 32150440 DOI: 10.1164/rccm.201909-1690oc] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Rationale: Tidal expiratory flow limitation (tidal-EFL) is not completely avoidable by applying positive end-expiratory pressure and may cause respiratory and hemodynamic complications in ventilated patients with lungs prone to collapse. During spontaneous breathing, expiratory diaphragmatic contraction counteracts tidal-EFL. We hypothesized that during both spontaneous breathing and controlled mechanical ventilation, external expiratory resistances reduce tidal-EFL.Objectives: To assess whether external expiratory resistances 1) affect expiratory diaphragmatic contraction during spontaneous breathing, 2) reduce expiratory flow and make lung compartments more homogeneous with more similar expiratory time constants, and 3) reduce tidal atelectasis, preventing hyperinflation.Methods: Three positive end-expiratory pressure levels and four external expiratory resistances were tested in 10 pigs after lung lavage. We analyzed expiratory diaphragmatic electric activity and respiratory mechanics. On the basis of computed tomography scans, four lung compartments-not inflated (atelectasis), poorly inflated, normally inflated, and hyperinflated-were defined.Measurements and Main Results: Consequently to additional external expiratory resistances, and mainly in lungs prone to collapse (at low positive end-expiratory pressure), 1) the expiratory transdiaphragmatic pressure decreased during spontaneous breathing by >10%, 2) expiratory flow was reduced and the expiratory time constants became more homogeneous, and 3) the amount of atelectasis at end-expiration decreased from 24% to 16% during spontaneous breathing and from 32% to 18% during controlled mechanical ventilation, without increasing hyperinflation.Conclusions: The expiratory modulation induced by external expiratory resistances preserves the positive effects of the expiratory brake while minimizing expiratory diaphragmatic contraction. External expiratory resistances optimize lung mechanics and limit tidal-EFL and tidal atelectasis, without increasing hyperinflation.
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Affiliation(s)
- Mariangela Pellegrini
- Department of Surgical Sciences and.,Central Intensive Care Unit, Department of Anesthesia, Operation, and Intensive Care and
| | - Magni Gudmundsson
- Department of Anesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Reka Bencze
- Department of Surgical Sciences and.,Central Intensive Care Unit, Department of Anesthesia, Operation, and Intensive Care and
| | - Monica Segelsjö
- Department of Radiology, Uppsala University Hospital, Uppsala, Sweden; and
| | - Filip Freden
- Department of Surgical Sciences and.,Central Intensive Care Unit, Department of Anesthesia, Operation, and Intensive Care and
| | - Christian Rylander
- Department of Anesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Göran Hedenstierna
- Department of Medical Sciences, Hedenstierna Laboratory, Uppsala University, Uppsala, Sweden
| | - Anders S Larsson
- Department of Surgical Sciences and.,Central Intensive Care Unit, Department of Anesthesia, Operation, and Intensive Care and
| | - Gaetano Perchiazzi
- Department of Surgical Sciences and.,Central Intensive Care Unit, Department of Anesthesia, Operation, and Intensive Care and
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9
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Gattinoni L, Marini JJ, Quintel M. Recruiting the Acutely Injured Lung: How and Why? Am J Respir Crit Care Med 2020; 201:130-132. [PMID: 31661307 PMCID: PMC6961753 DOI: 10.1164/rccm.201910-2005ed] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Luciano Gattinoni
- Department of Anesthesiology, Emergency and Intensive Care MedicineUniversity of GöttingenGöttingen, Germanyand
| | - John J Marini
- Regions Hospital and University of MinnesotaSt. Paul, Minnesota
| | - Michael Quintel
- Department of Anesthesiology, Emergency and Intensive Care MedicineUniversity of GöttingenGöttingen, Germanyand
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10
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Wang H, He H. Expiratory flow limitation developed in ICU patients: relationship of fluid overload, respiratory mechanics, and outcome. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2020; 24:24. [PMID: 31980028 PMCID: PMC6979074 DOI: 10.1186/s13054-019-2723-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 12/27/2019] [Indexed: 01/13/2023]
Affiliation(s)
- Heyan Wang
- Department of Critical Care Medicine, The Sixth Hospital of Guiyang, Guiyang City, Guizhou Province, China
| | - Hangyong He
- Department of Respiratory and Critical Care Medicine, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, No. 8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing, 100020, China.
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11
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Volta CA, Dalla Corte F, Ragazzi R, Marangoni E, Fogagnolo A, Scaramuzzo G, Grieco DL, Alvisi V, Rizzuto C, Spadaro S. Expiratory flow limitation in intensive care: prevalence and risk factors. Crit Care 2019; 23:395. [PMID: 31806045 PMCID: PMC6896682 DOI: 10.1186/s13054-019-2682-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/21/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Expiratory flow limitation (EFL) is characterised by a markedly reduced expiratory flow insensitive to the expiratory driving pressure. The presence of EFL can influence the respiratory and cardiovascular function and damage the small airways; its occurrence has been demonstrated in different diseases, such as COPD, asthma, obesity, cardiac failure, ARDS, and cystic fibrosis. Our aim was to evaluate the prevalence of EFL in patients requiring mechanical ventilation for acute respiratory failure and to determine the main clinical characteristics, the risk factors and clinical outcome associated with the presence of EFL. METHODS Patients admitted to the intensive care unit (ICU) with an expected length of mechanical ventilation of 72 h were enrolled in this prospective, observational study. Patients were evaluated, within 24 h from ICU admission and for at least 72 h, in terms of respiratory mechanics, presence of EFL through the PEEP test, daily fluid balance and followed for outcome measurements. RESULTS Among the 121 patients enrolled, 37 (31%) exhibited EFL upon admission. Flow-limited patients had higher BMI, history of pulmonary or heart disease, worse respiratory dyspnoea score, higher intrinsic positive end-expiratory pressure, flow and additional resistance. Over the course of the initial 72 h of mechanical ventilation, additional 21 patients (17%) developed EFL. New onset EFL was associated with a more positive cumulative fluid balance at day 3 (103.3 ml/kg) compared to that of patients without EFL (65.8 ml/kg). Flow-limited patients had longer duration of mechanical ventilation, longer ICU length of stay and higher in-ICU mortality. CONCLUSIONS EFL is common among ICU patients and correlates with adverse outcomes. The major determinant for developing EFL in patients during the first 3 days of their ICU stay is a positive fluid balance. Further studies are needed to assess if a restrictive fluid therapy might be associated with a lower incidence of EFL.
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Affiliation(s)
- Carlo Alberto Volta
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy
| | - Francesca Dalla Corte
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy
| | - Riccardo Ragazzi
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy
| | - Elisabetta Marangoni
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy
| | - Alberto Fogagnolo
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy
| | - Gaetano Scaramuzzo
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy
| | - Domenico Luca Grieco
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of The Sacred Heart, Milan, Italy
| | - Valentina Alvisi
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy
| | - Chiara Rizzuto
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy
- Department of Anesthesia and Intensive Care Unit, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Polo Universitario, University of Milan, Milan, Italy
| | - Savino Spadaro
- Department of Morphology, Surgery and Experimental Medicine, Azienda Ospedaliera-Universitaria Arcispedale Sant'Anna, University of Ferrara, Via Aldo Moro, 8, 44124, Ferrara, Italy.
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Coppola S, Caccioppola A, Froio S, Ferrari E, Gotti M, Formenti P, Chiumello D. Dynamic hyperinflation and intrinsic positive end-expiratory pressure in ARDS patients. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2019; 23:375. [PMID: 31775830 PMCID: PMC6880369 DOI: 10.1186/s13054-019-2611-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/13/2019] [Indexed: 02/02/2023]
Abstract
Background In ARDS patients, changes in respiratory mechanical properties and ventilatory settings can cause incomplete lung deflation at end-expiration. Both can promote dynamic hyperinflation and intrinsic positive end-expiratory pressure (PEEP). The aim of this study was to investigate, in a large population of ARDS patients, the presence of intrinsic PEEP, possible associated factors (patients’ characteristics and ventilator settings), and the effects of two different external PEEP levels on the intrinsic PEEP. Methods We made a secondary analysis of published data. Patients were ventilated with a tidal volume of 6–8 mL/kg of predicted body weight, sedated, and paralyzed. After a recruitment maneuver, a PEEP trial was run at 5 and 15 cmH2O, and partitioned mechanics measurements were collected after 20 min of stabilization. Lung computed tomography scans were taken at 5 and 45 cmH2O. Patients were classified into two groups according to whether or not they had intrinsic PEEP at the end of an expiratory pause. Results We enrolled 217 sedated, paralyzed patients: 87 (40%) had intrinsic PEEP with a median of 1.1 [1.0–2.3] cmH2O at 5 cmH2O of PEEP. The intrinsic PEEP significantly decreased with higher PEEP (1.1 [1.0–2.3] vs 0.6 [0.0–1.0] cmH2O; p < 0.001). The applied tidal volume was significantly lower (480 [430–540] vs 520 [445–600] mL at 5 cmH2O of PEEP; 480 [430–540] vs 510 [430–590] mL at 15 cmH2O) in patients with intrinsic PEEP, while the respiratory rate was significantly higher (18 [15–20] vs 15 [13–19] bpm at 5 cmH2O of PEEP; 18 [15–20] vs 15 [13–19] bpm at 15 cmH2O). At both PEEP levels, the total airway resistance and compliance of the respiratory system were not different in patients with and without intrinsic PEEP. The total lung gas volume and lung recruitability were also not different between patients with and without intrinsic PEEP (respectively 961 [701–1535] vs 973 [659–1433] mL and 15 [0–32] % vs 22 [0–36] %). Conclusions In sedated, paralyzed ARDS patients without a known obstructive disease, the amount of intrinsic PEEP during lung-protective ventilation is negligible and does not influence respiratory mechanical properties.
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Affiliation(s)
- Silvia Coppola
- Department of Anesthesia and Intensive Care, ASST Santi Paolo e Carlo, San Paolo University Hospital, Milan, Italy
| | | | - Sara Froio
- Department of Anesthesia and Intensive Care, ASST Santi Paolo e Carlo, San Paolo University Hospital, Milan, Italy
| | - Erica Ferrari
- Department of Health Sciences, University of Milan, Milan, Italy
| | - Miriam Gotti
- Department of Anesthesia and Intensive Care, ASST Santi Paolo e Carlo, San Paolo University Hospital, Milan, Italy
| | - Paolo Formenti
- Department of Anesthesia and Intensive Care, ASST Santi Paolo e Carlo, San Paolo University Hospital, Milan, Italy
| | - Davide Chiumello
- Department of Anesthesia and Intensive Care, ASST Santi Paolo e Carlo, San Paolo University Hospital, Milan, Italy. .,Department of Health Sciences, University of Milan, Milan, Italy. .,Coordinated Research Center on Respiratory Failure, University of Milan, Milan, Italy. .,SC Anestesia e Rianimazione, ASST Santi Paolo e Carlo, Via Di Rudinì, Milan, Italy.
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Koutsoukou A. Expiratory Flow Limitation and Airway Closure in Patients with Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med 2019; 199:127-128. [PMID: 30256658 DOI: 10.1164/rccm.201807-1253le] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Koutsoukou A, Pecchiari M. Expiratory flow-limitation in mechanically ventilated patients: A risk for ventilator-induced lung injury? World J Crit Care Med 2019; 8:1-8. [PMID: 30697515 PMCID: PMC6347666 DOI: 10.5492/wjccm.v8.i1.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/24/2018] [Accepted: 10/17/2018] [Indexed: 02/06/2023] Open
Abstract
Expiratory flow limitation (EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety of intensive care unit conditions. Recent evidence suggests that the presence of EFL is associated with an increase in mortality, at least in acute respiratory distress syndrome (ARDS) patients, and in pulmonary complications in patients undergoing surgery. EFL is a major cause of intrinsic positive end-expiratory pressure (PEEPi), which in ARDS patients is heterogeneously distributed, with a consequent increase of ventilation/perfusion mismatch and reduction of arterial oxygenation. Airway collapse is frequently concomitant to the presence of EFL. When airways close and reopen during tidal ventilation, abnormally high stresses are generated that can damage the bronchiolar epithelium and uncouple small airways from the alveolar septa, possibly generating the small airways abnormalities detected at autopsy in ARDS. Finally, the high stresses and airway distortion generated downstream the choke points may contribute to parenchymal injury, but this possibility is still unproven. PEEP application can abolish EFL, decrease PEEPi heterogeneity, and limit recruitment/derecruitment. Whether increasing PEEP up to EFL disappearance is a useful criterion for PEEP titration can only be determined by future studies.
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Affiliation(s)
- Antonia Koutsoukou
- ICU, 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens Medical School, Athens 11527, Greece
| | - Matteo Pecchiari
- Dipartimento di Fisiopatologia e dei Trapianti, Università degli Studi di Milano, Milan 20133, Italy
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Yonis H, Mortaza S, Baboi L, Mercat A, Guérin C. Expiratory Flow Limitation Assessment in Patients with Acute Respiratory Distress Syndrome. A Reappraisal. Am J Respir Crit Care Med 2018; 198:131-134. [DOI: 10.1164/rccm.201711-2326le] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
| | | | | | - Alain Mercat
- CHU LarreyAngers, France
- Université d’AngersAngers, France
| | - Claude Guérin
- Hospices Civils de LyonLyon, France
- Université de LyonLyon, Franceand
- INSERM 955Créteil, France
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Ortiz G, Garay M, Capelozzi V, Cardinal-Fernández P. Airway Pathological Alterations Selectively Associated With Acute Respiratory Distress Syndrome and Diffuse Alveolar Damage - Narrative Review. Arch Bronconeumol 2018; 55:31-37. [PMID: 29853259 DOI: 10.1016/j.arbres.2018.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/16/2018] [Accepted: 03/07/2018] [Indexed: 12/12/2022]
Abstract
Acute respiratory distress syndrome (ARDS) is a frequent and life-threatening entity. Recently, it has been demonstrated that diffuse alveolar damage (DAD), which is considered the histological hallmark in spite of presenting itself in only half of living patients with ARDS, exerts a relevant effect in the ARDS outcome. Despite the fact that the bronchial tree constitutes approximately 1% of the lung volume, discovering a relation between DAD and bronchial tree findings could be of paramount importance for a few reasons; (a) it could improve the description of ARDS with DAD as a clinical-pathological entity, (b) it could subrogate DAD findings with the advantage of their more accessible and safer analysis and (c) it could allow the discovery of new therapeutic targets. This narrative review is focused on pathological airway changes associated to Diffuse Alveolar Damage in the context of Acute Respiratory Distress Syndrome. It is organized into five sections: main anatomical and functional features of the human airway, why it is necessary to study airway features associated to DAD in patients with ARDS, pathological airway changes associated with DAD in animal models of ARDS, pathological airway changes associated with DAD in patients with ARDS, and the newest techniques for studying the histology of the bronchial tree and lung parenchyma.
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Affiliation(s)
- Guillermo Ortiz
- Universidad del Bosque, Bogotá, Colombia; Universidad de Barcelona, Barcelona, Spain
| | | | - Vera Capelozzi
- Department of Pathology, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Pablo Cardinal-Fernández
- Emergency Department, Hospital Universitario HM Sanchinarro, Madrid, Spain; HM Research Foundation, Madrid, Spain.
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Junhasavasdikul D, Telias I, Grieco DL, Chen L, Gutierrez CM, Piraino T, Brochard L. Expiratory Flow Limitation During Mechanical Ventilation. Chest 2018; 154:948-962. [PMID: 29432712 DOI: 10.1016/j.chest.2018.01.046] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 01/27/2018] [Accepted: 01/30/2018] [Indexed: 12/13/2022] Open
Abstract
Expiratory flow limitation (EFL) is present when the flow cannot rise despite an increase in the expiratory driving pressure. The mechanisms of EFL are debated but are believed to be related to the collapsibility of small airways. In patients who are mechanically ventilated, EFL can exist during tidal ventilation, representing an extreme situation in which lung volume cannot decrease, regardless of the expiratory driving forces. It is a key factor for the generation of auto- or intrinsic positive end-expiratory pressure (PEEP) and requires specific management such as positioning and adjustment of external PEEP. EFL can be responsible for causing dyspnea and patient-ventilator dyssynchrony, and it is influenced by the fluid status of the patient. EFL frequently affects patients with COPD, obesity, and heart failure, as well as patients with ARDS, especially at low PEEP. EFL is, however, most often unrecognized in the clinical setting despite being associated with complications of mechanical ventilation and poor outcomes such as postoperative pulmonary complications, extubation failure, and possibly airway injury in ARDS. Therefore, prompt recognition might help the management of patients being mechanically ventilated who have EFL and could potentially influence outcome. EFL can be suspected by using different means, and this review summarizes the methods to specifically detect EFL during mechanical ventilation.
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Affiliation(s)
- Detajin Junhasavasdikul
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada; Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada; Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Irene Telias
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada; Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
| | - Domenico Luca Grieco
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada; Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada; Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli," Rome, Italy
| | - Lu Chen
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada; Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
| | - Cinta Millan Gutierrez
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada; Critical Care Center, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Thomas Piraino
- Department of Respiratory Therapy, St. Michael's Hospital, Toronto, ON, Canada; Department of Anesthesia, McMaster University, Hamilton, ON, Canada
| | - Laurent Brochard
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada; Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada.
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Chen L, Del Sorbo L, Grieco DL, Shklar O, Junhasavasdikul D, Telias I, Fan E, Brochard L. Airway Closure in Acute Respiratory Distress Syndrome: An Underestimated and Misinterpreted Phenomenon. Am J Respir Crit Care Med 2018; 197:132-136. [DOI: 10.1164/rccm.201702-0388le] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Lu Chen
- University of TorontoToronto, Canada
- St. Michael’s HospitalToronto, Canada
| | - Lorenzo Del Sorbo
- University of TorontoToronto, Canada
- Toronto General HospitalToronto, Canada
| | - Domenico Luca Grieco
- University of TorontoToronto, Canada
- Catholic University of the Sacred HeartRome, Italyand
| | | | | | | | - Eddy Fan
- University of TorontoToronto, Canada
- Toronto General HospitalToronto, Canada
| | - Laurent Brochard
- University of TorontoToronto, Canada
- St. Michael’s HospitalToronto, Canada
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Henderson WR, Chen L, Amato MBP, Brochard LJ. Fifty Years of Research in ARDS. Respiratory Mechanics in Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med 2017; 196:822-833. [PMID: 28306327 DOI: 10.1164/rccm.201612-2495ci] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Acute respiratory distress syndrome is a multifactorial lung injury that continues to be associated with high levels of morbidity and mortality. Mechanical ventilation, although lifesaving, is associated with new iatrogenic injury. Current best practice involves the use of small Vt, low plateau and driving pressures, and high levels of positive end-expiratory pressure. Collectively, these interventions are termed "lung-protective ventilation." Recent investigations suggest that individualized measurements of pulmonary mechanical variables rather than population-based ventilation prescriptions may be used to set the ventilator with the potential to improve outcomes beyond those achieved with standard lung protective ventilation. This review outlines the measurement and application of clinically applicable pulmonary mechanical concepts, such as plateau pressures, driving pressure, transpulmonary pressures, stress index, and measurement of strain. In addition, the concept of the "baby lung" and the utility of dynamic in addition to static measures of pulmonary mechanical variables are discussed.
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Affiliation(s)
- William R Henderson
- 1 Division of Critical Care Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lu Chen
- 2 Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada.,3 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada; and
| | - Marcelo B P Amato
- 4 Cardio-Pulmonary Department, Pulmonary Division, Heart Institute (Incor), University of São Paulo, São Paulo, Brazil
| | - Laurent J Brochard
- 2 Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada.,3 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada; and
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20
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Tripathi M, Tripathi N, Pandey M. Asynchrony Between Ventilator Flow and Pressure Waveforms and the Capnograph on Dräger Anesthesia Workstations: A Case Report. ACTA ACUST UNITED AC 2017; 8:122-125. [PMID: 27941478 DOI: 10.1213/xaa.0000000000000445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Modern anesthesia workstations display capnography, flow-time, and pressure-time waveforms in real time. We observed that at certain ventilator settings (10 breaths/min) on Dräger workstations, the expiratory phase of the capnograph overlaps both the inspiratory and the expiratory phases of ventilation. This discrepancy disappears at respiratory rates of 16 breaths/min. This synchronous respiratory monitoring display at respiratory rates 16 breaths/min is not physiologically correct, because it implies a synchronization of waveforms that is not actually present. This again becomes asynchronous once the respiratory rate is increased to >18 breaths/min. Such an artifact may not affect the patient's safety in most cases but may mislead clinicians when synchrony between flow/pressure and capnography is needed for diagnostic purposes. We wish to share this discrepancy with clinicians and notify the manufacturer so that potential solutions may be found.
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Affiliation(s)
- Mukesh Tripathi
- From the *Department of Anesthesiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow; †Ursila District Hospital, Kanpur; ‡Emergency Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Ntoumenopoulos G. Indications for manual lung hyperinflation (MHI) in the mechanically ventilated patient with chronic obstructivepulmonary disease. Chron Respir Dis 2016; 2:199-207. [PMID: 16541603 DOI: 10.1191/1479972305cd080oa] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Manual lung hyperinflation (MHI) can enhance secretion clearance, improve total lung/thorax compliance and assistin the resolution of acute atelectasis. To enhance secretion clearance in the intubated patient, the evidence highlights the need to maximize expiratory flow. Chronic pulmonary diseases such as chronic obstructive pulmonary disease(COPD) have often been cited as potential precautions and/or contra-indications to the use of manual lung hyperinflation (MHI). There is an absence of evidence on the effects of MHI in the patient with COPD. Research on the effects of mechanical ventilation in the patient with COPD providesa useful clinical examination of the effect of positive pressure on cardiac and pulmonary function. The potential effects of MHI in the COPD patient group were extrapolated on the basis of the MHI and mechanical ventilation literature. There is the potential for MHI to have both detrimental and beneficial effects on cardiac and pulmonary functionin patients with COPD. The potential detrimental effects of MHI may include either, increased intrinsic peep throughinadequate time for expiration by the breath delivery rate, tidal volume delivered or through the removal of appliedextemal PEEP thereby causing more dynamic airway compression compromising downward expiratory flow, which may also retard bronchial mucus transport. MHI may also increase right ventricular after load through raised intrathoracic pressures with lung hyperinflation, and may therefore impair right ventricular function in patients with evidence of cor pulmonale. There is the potential for beneficial effectsfrom MHI in the intubated COPD patient group (i.e., secretion clearance), but further research is required, especially on the effect of MHI on inspiratory and expiratory flowrate profiles in this patient group. The more controlled delivery of lung hyperinflation through the use of the mechanical ventilator may be a more optimal means of providinglunghyperinflation and shouldbe furtherinvestigated.
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Affiliation(s)
- G Ntoumenopoulos
- Clinical Specialist Respiratory Physiotherapist, Guys and St Thomas' Trust, London, UK.
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Das SK, Chopoo NS. "Undulation on ventilator wave" may indicate serious lung pathology. Lung India 2016; 33:103-5. [PMID: 26933323 PMCID: PMC4748646 DOI: 10.4103/0970-2113.173081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Saurabh Kumar Das
- Department of Anesthesia and Critical Care, Nazareth Hospital, Shillong, Meghalaya, India E-mail:
| | - Nang Sujali Chopoo
- Department of Anesthesia and Critical Care, Nazareth Hospital, Shillong, Meghalaya, India E-mail:
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Spaeth J, Ott M, Karzai W, Grimm A, Wirth S, Schumann S, Loop T. Double-lumen tubes and auto-PEEP during one-lung ventilation. Br J Anaesth 2016; 116:122-30. [DOI: 10.1093/bja/aev398] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Guerin C, Richard JC. Current ventilatory management of patients with acute lung injury/acute respiratory distress syndrome. Expert Rev Respir Med 2014; 2:119-33. [DOI: 10.1586/17476348.2.1.119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Effects of sitting position and applied positive end-expiratory pressure on respiratory mechanics of critically ill obese patients receiving mechanical ventilation*. Crit Care Med 2013; 41:2592-9. [PMID: 23939358 DOI: 10.1097/ccm.0b013e318298637f] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the extent to which sitting position and applied positive end-expiratory pressure improve respiratory mechanics of severely obese patients under mechanical ventilation. DESIGN Prospective cohort study. SETTINGS A 15-bed ICU of a tertiary hospital. PARTICIPANTS Fifteen consecutive critically ill patients with a body mass index (the weight in kilograms divided by the square of the height in meters) above 35 were compared to 15 controls with body mass index less than 30. INTERVENTIONS Respiratory mechanics was first assessed in the supine position, at zero end-expiratory pressure, and then at positive end-expiratory pressure set at the level of auto-positive endexpiratory pressure. Second, all measures were repeated in the sitting position. MEASUREMENTS AND MAIN RESULTS Assessment of respiratory mechanics included plateau pressure, auto-positive end-expiratory pressure, and flow-limited volume during manual compression of the abdomen, expressed as percentage of tidal volume to evaluate expiratory flow limitation. In supine position at zero end-expiratory pressure, all critically ill obese patients demonstrated expiratory flow limitation (flow-limited volume, 59.4% [51.3-81.4%] vs 0% [0-0%] in controls; p < 0.0001) and greater auto-positive end-expiratory pressure (10 [5-12.5] vs 0.7 [0.4-1.25] cm H2O in controls; p < 0.0001). Applied positive end-expiratory pressure reverses expiratory flow limitation (flow-limited volume, 0% [0-21%] vs 59.4% [51-81.4%] at zero end-expiratory pressure; p < 0.001) in almost all the obese patients, without increasing plateau pressure (24 [19-25] vs 22 [18-24] cm H2O at zero end-expiratory pressure; p = 0.94). Sitting position not only reverses partially or completely expiratory flow limitation at zero end-expiratory pressure (flow-limited volume, 0% [0-58%] vs 59.4% [51-81.4%] in supine obese patients; p < 0.001) but also results in a significant drop in auto-positive end-expiratory pressure (1.2 [0.6-4] vs 10 [5-12.5] cm H2O in supine obese patients; p < 0.001) and plateau pressure (15.6 [14-17] vs 22 [18-24] cm H2O in supine obese patients; p < 0.001). CONCLUSIONS In critically ill obese patients under mechanical ventilation, sitting position constantly and significantly relieved expiratory flow limitation and auto-positive end-expiratory pressure resulting in a dramatic drop in alveolar pressures. Combining sitting position and applied positive end-expiratory pressure provides the best strategy.
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Electrical activity of the diaphragm (EAdi) as a monitoring parameter in difficult weaning from respirator: a pilot study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:R182. [PMID: 23985299 PMCID: PMC4057029 DOI: 10.1186/cc12865] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 08/02/2013] [Indexed: 11/10/2022]
Abstract
INTRODUCTION A reliable prediction of successful weaning from respiratory support may be crucial for the overall outcome of the critically ill patient. The electrical activity of the diaphragm (EAdi) allows one to monitor the patients' respiratory drive and their ability to meet the increased respiratory demand. In this pilot study, we compared the EAdi with conventional parameters of weaning failure, such as the ratio of respiratory rate to tidal volume. METHODS We studied 18 mechanically ventilated patients considered difficult to wean. For a spontaneous breathing trial (SBT), the patients were disconnected from the ventilator and given oxygen through a T-piece. The SBT was evaluated by using standard criteria. RESULTS Twelve patients completed the SBT successfully, and six failed. The EAdi was significantly different in the two groups. We found an early increase in EAdi in the failing patients that was more pronounced than in any of the patients who successfully passed the SBT. Changes in EAdi predicted an SBT failure earlier than did conventional parameters. CONCLUSIONS EAdi monitoring adds valuable information during weaning from the ventilator and may help to identify patients who are not ready for discontinuation of respiratory support.
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Trojik T, Shosholcheva M, Radulovska-Chabukovska J, Lovach-Chepujnoska M. Evaluation of effects of repetitive recruitment maneuvers. Acta Inform Med 2013; 20:85-9. [PMID: 23322958 PMCID: PMC3544327 DOI: 10.5455/aim.2012.20.85-89] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 05/30/2012] [Indexed: 01/11/2023] Open
Abstract
Introduction: acute respiratory failure is manifested clinically as patient with variable degrees of respiratory distress, but characteristically an abnormal arterial blood partial pressure of oxygen or carbon dioxide. The application of mechanical ventilation in this setting can be life saving. Goals: The aim of this study is to evaluate the effects of two recruitment maneuvers not only on oxygenation, but on aeration of the lung as well. For that purpose chest x ray and thoracic computed tomography scan (CT) of the lung were used as safe and objective methods for evaluation the impact of recruitment maneuvers on aeration of the lung. CT scan and chest x ray were performed before recruitment maneuvers as confirmation of diagnose and one day after the last recruitment maneuvers. Material and methods: Sixty patients who met ar DS criteria of the american european consensus conference were included in this study. This study was conducted in iCU in our hospital between november 2009 and December 2011. Patients were orally intubated, sedated with 0, 2-0, 4 μg/kg /min and midazolam 4 mg/h, and ventilated with evita 2 Dura ventilator (Dragger germany). According to the recom-mendation of the Consensus Conference of the american College of Chest physician all patients had an arterial catheter and cen-tral venous catheter. Hemodynamic data were collected from Data Ohmeda monitors. Gas analyses were mesured from blood samples taken from arteria radialis. Partial pressure of oxygen of mixed blood was messured from blood sample taken from v jugularis interior. We used arterial blood colection syringe Bd preset, and blood samples were analyzed with aVl 995HB blood gas analiser. Results: Hemodynamic changes: there wasn’t any differences in heart rate, and mean arterial blood pressure before the recruitment five minutes and sixty minutes after the recruitment in both groups. respiratory mechanics: Highest values of the compliance are achived during the recruitment manouver in both groups. There was better improvment in compliance during the e sigh recruitment maneouver, then in Cpap recruitment maneouver. There was improvement in chest X ray in both groups. 93,4% of patients in the Cpap group and 96,7% in e sigh group. CT scan: in Cpap group there were 8 patients with focal changes and 22 patients with diffusse changes. in e sigh group 29 patients had diffuse changes of the lung and one patient had focal changes. We noticed that there was better improvment in aeration in patients with diffuse changes of the lung 96.7% in e sigh group and 73,3% in Cpapgroup. In patient with focal changes there was improvment in 26,7% in e sigh group and 3,3% in Cpap group. We noticed that there was better improvmnet in aeration in patients with diffuse changes than in patients with focal changes. E sigh maneuver had better impact on aeration of the lung then Cpap recruitment maneuver. Conclusion: In our study we proved that e sigh recruitment maneuvers better improved oxygenation in arterial blood than Cpap recruitment maneuver. Repetative e sigh manouvers proved to be essential for arDS patients. They reopened collapsed alveolli and improved aeration of the lung which was confirmed by X ray and CT scan as an objective methods for verification of lung condition.
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Affiliation(s)
- Tatjana Trojik
- University Clinic for surgical diseases of "St. Naum Ohridski", Skopje R Macedonia ; University Clinic for surgical diseases of "St. Naum Ohridski", Skopje R Macedonia ; University Clinic for surgical diseases of "St. Naum Ohridski", Skopje R Macedonia
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Lin GM, Chen YJ, Li YH, Jaiteh LES, Han CL. The Effect of Hypoxia–Hypercapnia on Neuropsychological Function in Adult Respiratory Distress Syndrome. Am J Respir Crit Care Med 2012; 186:1307; author reply p. 1307-8. [DOI: 10.1164/ajrccm.186.12.1307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Respiratory mechanics in COPD patients who failed non-invasive ventilation: Role of intrinsic PEEP. Respir Physiol Neurobiol 2012; 184:35-40. [DOI: 10.1016/j.resp.2012.07.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 06/26/2012] [Accepted: 07/13/2012] [Indexed: 11/23/2022]
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Abstract
In critical care, the monitoring is essential to the daily care of ICU patients, as the optimization of patient's hemodynamic, ventilation, temperature, nutrition, and metabolism is the key to improve patients' survival. Indeed, the decisive endpoint is the supply of oxygen to tissues according to their metabolic needs in order to fuel mitochondrial respiration and, therefore, life. In this sense, both oxygenation and perfusion must be monitored in the implementation of any resuscitation strategy. The emerging concept has been the enhancement of macrocirculation through sequential optimization of heart function and then judging the adequacy of perfusion/oxygenation on specific parameters in a strategy which was aptly coined “goal directed therapy.” On the other hand, the maintenance of normal temperature is critical and should be regularly monitored. Regarding respiratory monitoring of ventilated ICU patients, it includes serial assessment of gas exchange, of respiratory system mechanics, and of patients' readiness for liberation from invasive positive pressure ventilation. Also, the monitoring of nutritional and metabolic care should allow controlling nutrients delivery, adequation between energy needs and delivery, and blood glucose. The present paper will describe the physiological basis, interpretation of, and clinical use of the major endpoints of perfusion/oxygenation adequacy and of temperature, respiratory, nutritional, and metabolic monitorings.
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Alvisi V, Marangoni E, Zannoli S, Uneddu M, Uggento R, Farabegoli L, Ragazzi R, Milic-Emili J, Belloni GP, Alvisi R, Volta CA. Pulmonary function and expiratory flow limitation in acute cervical spinal cord injury. Arch Phys Med Rehabil 2012; 93:1950-6. [PMID: 22543017 DOI: 10.1016/j.apmr.2012.04.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 03/28/2012] [Accepted: 04/08/2012] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To identify the nature of the changes of respiratory mechanics in patients with middle cervical spinal cord injury (SCI) and their correlation with posture. DESIGN Clinical trial. SETTING Acute SCI unit. PARTICIPANTS Patients with SCI (N=34) at C4-5 level studied within 6 months of injury. INTERVENTIONS Patients were assessed by the negative expiratory pressure test, maximal static respiratory pressure test, and standard spirometry. MAIN OUTCOME MEASURES The following respiratory variables were recorded in both the semirecumbent and supine positions: (1) tidal expiratory flow limitation (TEFL); (2) airway resistances; (3) mouth occlusion pressure developed 0.1 seconds after occluded inspiration at functional residual capacity (P(0.1)); (4) maximal static inspiratory pressure (MIP) and maximal static expiratory pressure (MEP); and (5) spirometric data. RESULTS TEFL was detected in 32% of the patients in the supine position and in 9% in the semirecumbent position. Airway resistances and P(0.1) were much higher compared with normative values, while MIP and MEP were markedly reduced. The ratio of forced expiratory volume in 1 second to forced vital capacity was less than 70%, while the other spirometric data were reduced up to 30% of predicted values. CONCLUSIONS Patients with middle cervical SCI can develop TEFL. The presence of TEFL, associated with increased airway resistance, could increase the work of breathing in the presence of a reduced capacity of the respiratory muscles to respond to the increased load. The semirecumbent position and the use of continuous positive airway pressure can be helpful to (1) reduce the extent of TEFL and avoid the opening/closure of the small airways; (2) decrease airway resistance; and (3) maintain the expiratory flow as high as possible, which aids in the removal of secretions.
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Affiliation(s)
- Valentina Alvisi
- Department of Surgical, Anaesthesiological and Radiological Sciences, Section of Anaesthesia and Intensive Care, University of Ferrara, Ferrara, Italy
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Marini JJ. Dynamic hyperinflation and auto-positive end-expiratory pressure: lessons learned over 30 years. Am J Respir Crit Care Med 2011; 184:756-62. [PMID: 21700908 DOI: 10.1164/rccm.201102-0226pp] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Auto-positive end-expiratory pressure (auto-PEEP; AP) and dynamic hyperinflation (DH) may affect hemodynamics, predispose to barotrauma, increase work of breathing, cause dyspnea, disrupt patient-ventilator synchrony, confuse monitoring of hemodynamics and respiratory system mechanics, and interfere with the effectiveness of pressure-regulated ventilation. Although basic knowledge regarding the clinical physiology and management of AP during mechanical ventilation has evolved impressively over the 30 years since DH and AP were first brought to clinical attention, novel and clinically relevant characteristics of this complex phenomenon continue to be described. This discussion reviews some of the more important aspects of AP that bear on the care of the ventilated patient with critical illness.
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Affiliation(s)
- John J Marini
- Pulmonary and Critical Care Medicine, University of Minnesota, St Paul, MN 55101-2595, USA.
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Correger E, Murias G, Chacon E, Estruga A, Sales B, Lopez-Aguilar J, Montanya J, Lucangelo U, Garcia-Esquirol O, Villagra A, Villar J, Kacmarek RM, Burgueño MJ, Blanch L. [Interpretation of ventilator curves in patients with acute respiratory failure]. Med Intensiva 2011; 36:294-306. [PMID: 22014424 DOI: 10.1016/j.medin.2011.08.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 08/08/2011] [Accepted: 08/30/2011] [Indexed: 11/17/2022]
Abstract
Mechanical ventilation is a therapeutic intervention involving the temporary replacement of ventilatory function with the purpose of improving symptoms in patients with acute respiratory failure. Technological advances have facilitated the development of sophisticated ventilators for viewing and recording the respiratory waveforms, which are a valuable source of information for the clinician. The correct interpretation of these curves is crucial for the correct diagnosis and early detection of anomalies, and for understanding physiological aspects related to mechanical ventilation and patient-ventilator interaction. The present study offers a guide for the interpretation of the airway pressure and flow and volume curves of the ventilator, through the analysis of different clinical scenarios.
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Affiliation(s)
- E Correger
- Grupo de Trabajo en Fisiopatología Pulmonar Experimental, Cátedra de Fisiología, FCM, UNLP, Hospital El Cruce y Fundación Favaloro, Buenos Aires, Argentina
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Does positive end-expiratory pressure improve CO(2) exchange in controlled ventilation of acute airflow obstruction? Crit Care Med 2011; 39:1841-2. [PMID: 21685757 DOI: 10.1097/ccm.0b013e3182204ac0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Passath C, Takala J, Tuchscherer D, Jakob SM, Sinderby C, Brander L. Physiologic Response to Changing Positive End-Expiratory Pressure During Neurally Adjusted Ventilatory Assist in Sedated, Critically Ill Adults. Chest 2010; 138:578-87. [DOI: 10.1378/chest.10-0286] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Bumbasirević V, Jovanović B, Bajec DD, Terziski Z, Pandurović M, Gregorić PD, Radenković DV, Ivancević ND, Jeremić V, Djukić VR. [Acute lung injury and acute respiratory distress syndrome--what should we know?]. ACTA CHIRURGICA IUGOSLAVICA 2010; 57:25-32. [PMID: 21449134 DOI: 10.2298/aci1004025b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Acutelunginjury (ALI) and its more severe form acute respiratory distress syndrome (ARDS) are syndromes with a spectrum of increasing severity of lung injury defined by physiologic and radiographic criteria. There are many clinical disorders as sociated with the development of ALI/ARDS and can be divided into those associated with direct or indirect lung injury. Early detection and protective lung ventilation strategy contribute to lowering the mortality rate.
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Affiliation(s)
- Vesna Bumbasirević
- Klinika za anesteziologiju i reanimatologiju, Urgentni centar, KCS, Beograd
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History of mechanical ventilation may affect respiratory mechanics evolution in acute respiratory distress syndrome. J Crit Care 2009; 24:626.e1-6. [PMID: 19427758 DOI: 10.1016/j.jcrc.2009.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 02/03/2009] [Accepted: 02/16/2009] [Indexed: 12/17/2022]
Abstract
PURPOSE The aim of this study was to investigate the effect of mechanical ventilation (MV) before acute respiratory distress syndrome (ARDS) on subsequent evolution of respiratory mechanics and blood gases in protectively ventilated patients with ARDS. METHODS Nineteen patients with ARDS were stratified into 2 groups according to ARDS onset relative to the onset of MV: In group A (n = 11), MV was applied at the onset of ARDS; in group B (n = 8), MV had been initiated before ARDS. Respiratory mechanics and arterial blood gas were assessed in early (<or=3 days) and late (8-11 days) ARDS, on zero positive end-expiratory pressure and positive end-expiratory pressure of 10 cm H(2)O. RESULTS In group A, Pao(2)/fractional inspired oxygen concentration increased (121 +/- 43 vs 161 +/- 60 mm Hg) and minimal resistance of respiratory system decreased (8.3 +/- 1.8 vs 6.0 +/- 2.1 cm H(2)O L(-1) s(-1)) from early to late ARDS. In group B, static elastance of respiratory system increased in the late stage (30.4 +/- 7.8 vs 36.4 +/- 9.9 cm H(2)O/L). In both groups, positive end-expiratory pressure application resulted in Pao(2)/fractional inspired oxygen concentration improvement and minimal resistance of respiratory system decreases in both stages. CONCLUSION In protectively ventilated patients with ARDS, late alteration of respiratory mechanics occurs more commonly in patients who have been ventilated before ARDS onset, suggesting that the history of MV affects the subsequent progress of ARDS even when using protective ventilation.
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Constantin JM, Jaber S, Futier E, Cayot-Constantin S, Verny-Pic M, Jung B, Bailly A, Guerin R, Bazin JE. Respiratory effects of different recruitment maneuvers in acute respiratory distress syndrome. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2008; 12:R50. [PMID: 18416847 PMCID: PMC2447604 DOI: 10.1186/cc6869] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 03/31/2008] [Accepted: 04/16/2008] [Indexed: 12/11/2022]
Abstract
Introduction Alveolar derecruitment may occur during low tidal volume ventilation and may be prevented by recruitment maneuvers (RMs). The aim of this study was to compare two RMs in acute respiratory distress syndrome (ARDS) patients. Methods Nineteen patients with ARDS and protective ventilation were included in a randomized crossover study. Both RMs were applied in each patient, beginning with either continuous positive airway pressure (CPAP) with 40 cm H2O for 40 seconds or extended sigh (eSigh) consisting of a positive end-expiratory pressure maintained at 10 cm H2O above the lower inflection point of the pressure-volume curve for 15 minutes. Recruited volume, arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2), and hemodynamic parameters were recorded before (baseline) and 5 and 60 minutes after RM. All patients had a lung computed tomography (CT) scan before study inclusion. Results Before RM, PaO2/FiO2 was 151 ± 61 mm Hg. Both RMs increased oxygenation, but the increase in PaO2/FiO2 was significantly higher with eSigh than CPAP at 5 minutes (73% ± 25% versus 44% ± 28%; P < 0.001) and 60 minutes (68% ± 23% versus 35% ± 22%; P < 0.001). Only eSigh significantly increased recruited volume at 5 and 60 minutes (21% ± 22% and 21% ± 25%; P = 0.0003 and P = 0.001, respectively). The only difference between responders and non-responders was CT lung morphology. Eleven patients were considered as recruiters with eSigh (10 with diffuse loss of aeration) and 6 with CPAP (5 with diffuse loss of aeration). During CPAP, 2 patients needed interruption of RM due to a drop in systolic arterial pressure. Conclusion Both RMs effectively increase oxygenation, but CPAP failed to increase recruited volume. When the lung is recruited with an eSigh adapted for each patient, alveolar recruitment and oxygenation are superior to those observed with CPAP.
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Affiliation(s)
- Jean-Michel Constantin
- General Intensive Care Unit, Hotel-Dieu Hospital, University Hospital of Clermont-Ferrand, Boulevard L, Malfreyt, 63058 Clermond-Ferrand, France.
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Guérin C, Levrat A, Pontier S, Annat G. A study of experimental acute lung injury in pigs on zero end-expiratory pressure. Vet Anaesth Analg 2008; 35:122-31. [DOI: 10.1111/j.1467-2995.2007.00363.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
In the intensive care setting, monitored data relevant to the output, efficiency, and reserve of the respiratory system alert the clinician to sudden untoward events, aid in diagnosis, help guide management decisions, aid in determining prognosis, and enable the assessment of therapeutic response. This review addresses those aspects of monitoring we find of most value in the care of patients receiving ventilatory support. We concentrate on those modalities and variables that are routinely available or easily calculated from data readily collected at the bedside.
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Affiliation(s)
- Vasileios Bekos
- Department of Intensive Care, Naval Hospital of Athens, 229 Messogion Avenue, 15561 Cholargos, Athens, Greece
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Di Marco F, Rota Sperti L, Milan B, Stucchi R, Centanni S, Brochard L, Fumagalli R. Measurement of functional residual capacity by helium dilution during partial support ventilation: in vitro accuracy and in vivo precision of the method. Intensive Care Med 2007; 33:2109-15. [PMID: 17703280 DOI: 10.1007/s00134-007-0833-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Accepted: 07/19/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Measurement of functional residual capacity (FRC) during controlled and especially during assisted ventilation remains a challenge in the physiological evaluation of ventilated patients. To validate a bag-in-box closed helium dilution technique allowing measurements both during pressure-controlled (PCV) and pressure-support ventilation (PSV). DESIGN AND SETTING Experimental study on lung models containing different volumes, and measurements in patients in the intensive care unit of a university hospital. In patients measurements were performed in duplicate during controlled and assisted ventilation. PATIENTS Thirty-three patients (aged 57+/-17 years) mechanically ventilated with PCV and PSV. MEASUREMENTS AND RESULTS In the lung model assessment of accuracy showed an overall mean difference between FRC measurements and lung model volume of 0.5% (2 SD 5.7%). In patients assessment of repeatability showed a bias between duplicate FRC measurements of -1+/-70 ml (95% CI -141 to +139 ml). The coefficient of variation was of 3.2% for all measurements with a comparable repeatability in PSV and PCV mode (coefficient of variation of 3.4 and 3.2%, respectively). During the rebreathing period a small reduction in tidal volume (-8.5+/-5.4%) and mean airway pressure (-2.3+/-4.7%) was observed with only a 0.3 cmH2O mean increase in PEEP and no change in respiratory rate and I/E ratio. CONCLUSIONS This specifically designed closed helium dilution bag-in-box technique allows accurate FRC measurement with good repeatability during both partial PSV and PVC without exposing patients to disconnection and changes in PEEP.
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Affiliation(s)
- Fabiano Di Marco
- Università degli Studi di Milano, II Clinica di Malattie dell'Apparato Respiratorio, Ospedale San Paolo, Via A. di Rudinì 8, 20142, Milan, Italy.
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Koutsoukou A, Koulouris NG. Why high levels of positive end-expiratory pressure are required to maintain a stable end-expiratory lung volume in morbidly obese subjects. Acta Anaesthesiol Scand 2007; 51:783-4. [PMID: 17488311 DOI: 10.1111/j.1399-6576.2007.01330.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
PURPOSE OF REVIEW To summarize current knowledge on pathophysiology and treatment of drowning accidents. Studies and case reports were searched using the keywords drowning, near-drowning, asphyxia, hypoxia and hypothermia in conjunction with organ systems and specific treatment options. RECENT FINDINGS Drowning is defined as death by suffocation in a liquid. In contrast, near-drowning is defined as survival beyond 24 h after a drowning accident. Drowning is a frequent preventable accident with a significant morbidity and mortality in a mostly healthy population. In the majority of patients the primary injury is pulmonary, resulting in severe arterial hypoxemia and secondary damage to other organs. Damage to the central nervous system is most critical in terms of patient survival and subsequent quality of life. Therefore, prompt resuscitation and aggressive respiratory and cardiovascular treatment are crucial for optimal survival. Immediate interruption of hypoxia, aggressive treatment of hypothermia and cardiovascular failure are the cornerstones of correct medical treatment. Unfortunately, accurate neurologic prognosis cannot be predicted from initial clinical presentation, laboratory, radiological or electrophysiological examinations. SUMMARY Several case studies have convincingly demonstrated that drowning victims may survive neurologically intact even after prolonged submersion times, in particular in cold water. Therefore, aggressive initial therapeutic efforts are indicated in most near-drowning victims.
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Affiliation(s)
- Walter R Hasibeder
- Division of General and Surgical Intensive Care Medicine, Department of Anaesthesia and Critical Care Medicine, The Leopold Franzens University of Innsbruck, Innsbruck, Austria.
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Milic-Emili J. Does mechanical injury of the peripheral airways play a role in the genesis of COPD in smokers? COPD 2006; 1:85-92. [PMID: 16997741 DOI: 10.1081/copd-120028700] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In the present account it is proposed that in smokers the transition from peripheral airway disease to COPD is characterized by three sequential stages: Stage I, during which the closing volume eventually exceeds the functional residual capacity; Stage II, during which tidal expiratory flow limitation (EFL) is eventually exhibited; and Stage III, during which dynamic hyperinflation progressively increases leading to dyspnea and exercise limitation, which may be considered as markers of overt disease. Presence of airway closure (Stage I) and EFL (Stage II) in the tidal volume range may promote peripheral airway injury and accelerate the abnormalities of lung function. It is such injury that may determine which smoker is destined to develop COPD.
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Affiliation(s)
- Joseph Milic-Emili
- Meakins-Christie Laboratories, McGill University, 3626 St. Urbain St., H2X 2P2, Montreal, Quebec, Canada.
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Koutsoukou A, Perraki H, Raftopoulou A, Koulouris N, Sotiropoulou C, Kotanidou A, Orfanos S, Roussos C. Respiratory mechanics in brain-damaged patients. Intensive Care Med 2006; 32:1947-54. [PMID: 17053881 DOI: 10.1007/s00134-006-0406-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Accepted: 09/18/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To assess respiratory mechanics on the 1st and 5th days of mechanical ventilation in a cohort of brain-damaged patients on positive end-expiratory pressure (PEEP) of 8 cmH(2)O or zero PEEP (ZEEP). DESIGN AND SETTING Physiological study with randomized control trial design in a multidisciplinary intensive care unit of a university hospital. PATIENTS AND MEASUREMENTS Twenty-one consecutive mechanically ventilated patients with severe brain damage and no acute lung injury were randomly assigned to be ventilated with ZEEP (n = 10) or with 8 cmH(2)O of PEEP (n = 11). Respiratory mechanics and arterial blood gases were assessed on days 1 and day 5 of mechanical ventilation. RESULTS In the ZEEP group on day 1 static elastance and minimal resistance were above normal limits (18.9 +/- 3.8 cmH(2)O/l and 5.6 +/- 2.2 cmH(2)O/l per second, respectively); on day 5 static elastance and iso-CO(2) minimal resistance values were higher than on day 1 (21.2 +/- 4.1 cmH(2)O/l; 7.0 +/- 1.9 cmH(2)O/l per second, respectively). In the PEEP group these parameters did not change significantly. One of the ten patients on ZEEP developed acute lung injury. On day 5 there was a significant decrease in PaO(2)/FIO(2) in both groups. CONCLUSIONS On day 1 of mechanical ventilation patients with brain damage exhibit abnormal respiratory mechanics. After 5 days of mechanical ventilation on ZEEP static elastance and minimal resistance increased significantly, perhaps reflecting "low lung volume" injury. Both could be prevented by administration of moderate levels of PEEP.
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Affiliation(s)
- Antonia Koutsoukou
- Department of Critical Care and Pulmonary Services, Evangelismos General Hospital and M Simou Laboratory, Medical School, University of Athens, Athens, Greece.
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Volta CA, Alvisi V, Bertacchini S, Marangoni E, Ragazzi R, Verri M, Alvisi R. Acute effects of hyperoxemia on dyspnoea and respiratory variables during pressure support ventilation. Intensive Care Med 2006; 32:223-229. [PMID: 16432678 DOI: 10.1007/s00134-005-0012-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2005] [Accepted: 11/07/2005] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate the acute effect of hyperoxemia on the comfort and the respiratory variables in patients undergoing pressure support ventilation (PSV) for acute respiratory failure (ARF). DESIGN AND SETTING Prospective, observational study performed in the intensive care unit of a university hospital. PATIENTS Thirteen semirecumbent patients were ventilated in PSV mode, the setting of which was established by the treating physician who was blinded to the study. MEASUREMENTS The variables measured at different levels (21-80%) of FiO(2) randomly applied were: minute volume (V (E)), respiratory frequency (f) and the pressure develing during the first 100 ms of an occluded breath (P(0.1)). These variables were firstly measured at the level of FiO(2) chosen by the treating physician. Severity of dyspnea was rated using the visual analogue scale 15' after each FiO(2) variation. RESULTS Modulation of FiO(2) was able to vary significantly the respiratory variables, since a FiO(2) increase was associated with a decrease in dyspnea, P(0.1), f, and V (E). While valuable variations were detected at both lower and higher values of FiO(2) than those established by the treating physician, a significant improvement in the respiratory variables was detected at FiO(2) 60%. The reduction in respiratory drive was statistically related to an amelioration of dyspnea (R(2)=0.89) even at values of FiO(2) higher than 60%. CONCLUSIONS During PSV the respiratory drive can be heavily modulated by varying the FiO(2) since even at FiO(2) greater than 0.6 dyspnea and respiratory variables continued to improve.
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Affiliation(s)
- Carlo Alberto Volta
- Department of Surgical, Anesthesiological and Radiological Science.Section of Anesthesia and Intensive Care, S.Anna Hospital, University of Ferrara, Corso Giovecca 203, 44100, Ferrara, Italy.
| | - Valentina Alvisi
- Department of Surgical, Anesthesiological and Radiological Science.Section of Anesthesia and Intensive Care, S.Anna Hospital, University of Ferrara, Corso Giovecca 203, 44100, Ferrara, Italy
| | - Sara Bertacchini
- Department of Surgical, Anesthesiological and Radiological Science.Section of Anesthesia and Intensive Care, S.Anna Hospital, University of Ferrara, Corso Giovecca 203, 44100, Ferrara, Italy
| | - Elisabetta Marangoni
- Department of Surgical, Anesthesiological and Radiological Science.Section of Anesthesia and Intensive Care, S.Anna Hospital, University of Ferrara, Corso Giovecca 203, 44100, Ferrara, Italy
| | - Riccardo Ragazzi
- Department of Surgical, Anesthesiological and Radiological Science.Section of Anesthesia and Intensive Care, S.Anna Hospital, University of Ferrara, Corso Giovecca 203, 44100, Ferrara, Italy
| | - Marco Verri
- Department of Surgical, Anesthesiological and Radiological Science.Section of Anesthesia and Intensive Care, S.Anna Hospital, University of Ferrara, Corso Giovecca 203, 44100, Ferrara, Italy
| | - Raffaele Alvisi
- Department of Surgical, Anesthesiological and Radiological Science.Section of Anesthesia and Intensive Care, S.Anna Hospital, University of Ferrara, Corso Giovecca 203, 44100, Ferrara, Italy
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Nunes S, Valta P, Takala J. Changes in respiratory mechanics and gas exchange during the acute respiratory distress syndrome. Acta Anaesthesiol Scand 2006; 50:80-91. [PMID: 16451155 DOI: 10.1111/j.1399-6576.2005.00767.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND The time course of impairment of respiratory mechanics and gas exchange in the acute respiratory distress syndrome (ARDS) remains poorly defined. We assessed the changes in respiratory mechanics and gas exchange during ARDS. We hypothesized that due to the changes in respiratory mechanics over time, ventilatory strategies based on rigid volume or pressure limits might fail to prevent overdistension throughout the disease process. METHODS Seventeen severe ARDS patients {PaO2/FiO2 10.1 (9.2-14.3) kPa; 76 (69-107) mmHg [median (25th-75th percentiles)] and bilateral infiltrates} were studied during the acute, intermediate, and late stages of ARDS (at 1-3, 4-6 and 7 days after diagnosis). Severity of lung injury, gas exchange, and hemodynamics were assessed. Pressure-volume (PV) curves of the respiratory system were obtained, and upper and lower inflection points (UIP, LIP) and recruitment were estimated. RESULTS (1) UIP decreased from early to established (intermediate and late) ARDS [30 (28-30) cmH2O, 27 (25-30) cmH2O and 25 (23-28) cmH2O (P=0.014)]; (2) oxygenation improved in survivors and in patients with non-pulmonary etiology in late ARDS, whereas all patients developed hypercapnia from early to established ARDS; and (3) dead-space ventilation and pulmonary shunt were larger in patients with pulmonary etiology during late ARDS. CONCLUSION We found a decrease in UIP from acute to established ARDS. If applied to our data, the inspiratory pressure limit advocated by the ARDSnet (30 cmH2O) would produce ventilation over the UIP, with a consequent increased risk of overdistension in 12%, 43% and 65% of our patients during the acute, intermediate and late phases of ARDS, respectively. Lung protective strategies based on fixed tidal volume or pressure limits may thus not fully avoid the risk of lung overdistension throughout ARDS.
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Affiliation(s)
- S Nunes
- Division of Intensive Care, Department of Anesthesiology and Intensive Care, Kuopio University Hospital, Kuopio, Finland.
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McAuley DF, Matthay MA. Is there a role for beta-adrenoceptor agonists in the management of acute lung injury and the acute respiratory distress syndrome? ACTA ACUST UNITED AC 2005; 4:297-307. [PMID: 16137187 DOI: 10.2165/00151829-200504050-00001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Despite improvements in general supportive care and ventilatory strategies designed to limit lung injury, no specific pharmacological therapy has yet proven to be efficacious in the management of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Based on experimental studies, as well as studies of the ex-vivo human lung, pulmonary edema fluid clearance from the alveolar space can be augmented by both inhaled and systemic beta2-adrenoceptor agonists (beta2-agonists). Additionally, in the presence of lung injury, beta2-agonists may reduce lung vascular permeability. Treatment with beta2-agonists may also increase the secretion of surfactant and have anti-inflammatory effects. In view of these potentially beneficial effects, beta2-agonist therapy should be evaluated for the treatment of lung injury in humans, particularly because they are already in wide clinical use and do not seem to have serious adverse effects in critically ill patients.
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Affiliation(s)
- Danny F McAuley
- Department of Medicine, Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94143-0624, USA
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50
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Pestaña D, Hernández-Gancedo C, Royo C, Pérez-Chrzanowska H, Criado A. Pressure-volume curve variations after a recruitment manoeuvre in acute lung injury/ARDS patients: implications for the understanding of the inflection points of the curve. Eur J Anaesthesiol 2005; 22:175-80. [PMID: 15852989 DOI: 10.1017/s0265021505000311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND OBJECTIVE Although the pressure-volume (P-V) curve has been proposed in the management of mechanically ventilated patients, its interpretation remains unclear. Our aim has been to study the variations of the P-V curve after a recruitment manoeuvre (RM). Our hypothesis was that the lower inflection point (LIP) represents the presence of compressive atelectases, so it should not change after lung recruitment, while the upper inflection point (UIP) reflects reabsorptive atelectases, and an effective recruitment should result in changes at this level. METHODS Two P-V curves (quasi-static method) separated by an RM (40 cmH2O, two consecutive manoeuvres) were plotted in 35 postoperative patients with criteria of acute lung injury/acute respiratory distress syndrome (ARDS). LIP, UIP and expiratory inflection point (EIP) were defined as the first point where the curve consistently starts to separate from the line. RESULTS One to six measurements were obtained per patient (73 procedures). Neither the lower nor the EIPs varied significantly after the RM (P = 0.11 and 0.35, respectively). An UIP was observed in 18 curves (25%) before the RM and disappeared on nine occasions after the recruitment. Similar results were obtained when first measurements only were analysed, and when the cause (pulmonary vs. extrapulmonary), severity of lung injury or duration of mechanical ventilation at first measurement were studied. CONCLUSIONS An RM does not modify the LIP significantly, but induces the disappearance of the UIP in 50% of the cases in which this point is found.
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Affiliation(s)
- D Pestaña
- Hospital Universitario La Paz, Servicio de Anestesia-Reanimación, Residencia General, Madrid, Spain.
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