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Camporota L, Rose L, Andrews PL, Nieman GF, Habashi NM. Airway pressure release ventilation for lung protection in acute respiratory distress syndrome: an alternative way to recruit the lungs. Curr Opin Crit Care 2024; 30:76-84. [PMID: 38085878 DOI: 10.1097/mcc.0000000000001123] [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: 01/03/2024]
Abstract
PURPOSE OF REVIEW Airway pressure release ventilation (APRV) is a modality of ventilation in which high inspiratory continuous positive airway pressure (CPAP) alternates with brief releases. In this review, we will discuss the rationale for APRV as a lung protective strategy and then provide a practical introduction to initiating APRV using the time-controlled adaptive ventilation (TCAV) method. RECENT FINDINGS APRV using the TCAV method uses an extended inspiratory time and brief expiratory release to first stabilize and then gradually recruit collapsed lung (over hours/days), by progressively 'ratcheting' open a small volume of collapsed tissue with each breath. The brief expiratory release acts as a 'brake' preventing newly recruited units from re-collapsing, reversing the main drivers of ventilator-induced lung injury (VILI). The precise timing of each release is based on analysis of expiratory flow and is set to achieve termination of expiratory flow at 75% of the peak expiratory flow. Optimization of the release time reflects the changes in elastance and, therefore, is personalized (i.e. conforms to individual patient pathophysiology), and adaptive (i.e. responds to changes in elastance over time). SUMMARY APRV using the TCAV method is a paradigm shift in protective lung ventilation, which primarily aims to stabilize the lung and gradually reopen collapsed tissue to achieve lung homogeneity eliminating the main mechanistic drivers of VILI.
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Affiliation(s)
- Luigi Camporota
- Department of Critical Care, Guy's & St Thomas' NHS Foundation Trust
- Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences
| | - Louise Rose
- Department of Critical Care, Guy's & St Thomas' NHS Foundation Trust
- Florence Nightingale Faculty of Nursing, Midwifery, and Palliative Care, King's College London, London, UK
| | - Penny L Andrews
- Department of Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, Maryland
| | - Gary F Nieman
- Department of Surgery, Upstate Medical University, Syracuse, New York, USA
| | - Nader M Habashi
- Department of Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, Maryland
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Caljé-van der Klei T, Sun Q, Chase JG, Zhou C, Tawhai MH, Knopp JL, Möller K, Heines SJ, Bergmans DC, Shaw GM. Pulmonary response prediction through personalized basis functions in a virtual patient model. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2024; 244:107988. [PMID: 38171168 DOI: 10.1016/j.cmpb.2023.107988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 11/16/2023] [Accepted: 12/17/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND AND OBJECTIVE Recruitment maneuvers with subsequent positive-end-expiratory-pressure (PEEP) have proven effective in recruiting lung volume and preventing alveoli collapse. However, determining a safe, effective, and patient-specific PEEP is not standardized, and this more optimal PEEP level evolves with patient condition, requiring personalised monitoring and care approaches to maintain optimal ventilation settings. METHODS This research examines 3 physiologically relevant basis function sets (exponential, parabolic, cumulative) to enable better prediction of elastance evolution for a virtual patient or digital twin model of MV lung mechanics, including novel elements to model and predict distension elastance. Prediction accuracy and robustness are validated against recruitment maneuver data from 18 volume-controlled ventilation (VCV) patients at 7 different baseline PEEP levels (0 to 12 cmH2O) and 14 pressure-controlled ventilation (PCV) patients at 4 different baseline PEEP levels (6 to 12 cmH2O), yielding 623 and 294 prediction cases, respectively. Predictions were made up to 12 cmH2O of added PEEP ahead, covering 6 × 2 cmH2O PEEP steps. RESULTS The 3 basis function sets yield median absolute peak inspiratory pressure (PIP) prediction error of 1.63 cmH2O for VCV patients, and median peak inspiratory volume (PIV) prediction error of 0.028 L for PCV patients. The exponential basis function set yields a better trade-off of overall performance across VCV and PCV prediction than parabolic and cumulative basis function sets from other studies. Comparing predicted and clinically measured distension prediction in VCV demonstrated consistent, robust high accuracy with R2 = 0.90-0.95. CONCLUSIONS The results demonstrate recruitment mechanics are best captured by an exponential basis function across different mechanical ventilation modes, matching physiological expectations, and accurately capture, for the first time, distension mechanics to within 5-10 % accuracy. Enabling the risk of lung injury to be predicted before changing ventilator settings. The overall outcomes significantly extend and more fully validate this digital twin or virtual mechanical ventilation patient model.
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Affiliation(s)
- Trudy Caljé-van der Klei
- Department of Mechanical Engineering, Centre for Bio-Engineering, University of Canterbury, Christchurch, New Zealand.
| | - Qianhui Sun
- Department of Mechanical Engineering, Centre for Bio-Engineering, University of Canterbury, Christchurch, New Zealand; University of Liége, Liége, Belgium
| | - J Geoffrey Chase
- Department of Mechanical Engineering, Centre for Bio-Engineering, University of Canterbury, Christchurch, New Zealand
| | - Cong Zhou
- Department of Mechanical Engineering, Centre for Bio-Engineering, University of Canterbury, Christchurch, New Zealand
| | - Merryn H Tawhai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Jennifer L Knopp
- Department of Mechanical Engineering, Centre for Bio-Engineering, University of Canterbury, Christchurch, New Zealand
| | - Knut Möller
- Institute for Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Serge J Heines
- Department of Intensive Care, School of Medicine, Maastricht University, Maastricht, Netherlands
| | - Dennis C Bergmans
- Department of Intensive Care, School of Medicine, Maastricht University, Maastricht, Netherlands
| | - Geoffrey M Shaw
- Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand
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Knudsen L, Hummel B, Wrede C, Zimmermann R, Perlman CE, Smith BJ. Acinar micromechanics in health and lung injury: what we have learned from quantitative morphology. Front Physiol 2023; 14:1142221. [PMID: 37025383 PMCID: PMC10070844 DOI: 10.3389/fphys.2023.1142221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/09/2023] [Indexed: 04/08/2023] Open
Abstract
Within the pulmonary acini ventilation and blood perfusion are brought together on a huge surface area separated by a very thin blood-gas barrier of tissue components to allow efficient gas exchange. During ventilation pulmonary acini are cyclically subjected to deformations which become manifest in changes of the dimensions of both alveolar and ductal airspaces as well as the interalveolar septa, composed of a dense capillary network and the delicate tissue layer forming the blood-gas barrier. These ventilation-related changes are referred to as micromechanics. In lung diseases, abnormalities in acinar micromechanics can be linked with injurious stresses and strains acting on the blood-gas barrier. The mechanisms by which interalveolar septa and the blood-gas barrier adapt to an increase in alveolar volume have been suggested to include unfolding, stretching, or changes in shape other than stretching and unfolding. Folding results in the formation of pleats in which alveolar epithelium is not exposed to air and parts of the blood-gas barrier are folded on each other. The opening of a collapsed alveolus (recruitment) can be considered as an extreme variant of septal wall unfolding. Alveolar recruitment can be detected with imaging techniques which achieve light microscopic resolution. Unfolding of pleats and stretching of the blood-gas barrier, however, require electron microscopic resolution to identify the basement membrane. While stretching results in an increase of the area of the basement membrane, unfolding of pleats and shape changes do not. Real time visualization of these processes, however, is currently not possible. In this review we provide an overview of septal wall micromechanics with focus on unfolding/folding as well as stretching. At the same time we provide a state-of-the-art design-based stereology methodology to quantify microarchitecture of alveoli and interalveolar septa based on different imaging techniques and design-based stereology.
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Affiliation(s)
- Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Centre for Lung Research (DZL), Hannover, Germany
| | - Benjamin Hummel
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany
| | - Richard Zimmermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Carrie E Perlman
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, United States
| | - Bradford J Smith
- Department of Bioengineering, College of Engineering Design and Computing, University of Colorado Denver | Anschutz Medical Campus, Aurora, CO, United States
- Department of Pediatric Pulmonary and Sleep Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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Pan P, Li L, Xie F, Hu X, Guo Y, Xie L, Su L. Physiological Regulation of Pulmonary Microcirculation under Mechanical Ventilation at Different Cardiac Outputs and Positive End-Expiratory Pressures in a Porcine Model. J Pers Med 2023; 13:jpm13010107. [PMID: 36675768 PMCID: PMC9861575 DOI: 10.3390/jpm13010107] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/06/2023] Open
Abstract
This study was performed to visualize the hemodynamic effects of pulmonary microcirculation and ventilation/perfusion (V/Q) matching after mechanical ventilation under different cardiac outputs and positive end-expiratory pressures (PEEPs). Ten experimental pigs were randomly divided into high and low tidal volume groups, and ventilation/perfusion were measured by electrical impedance tomography (EIT) at different PEEPs. Then, all the pigs were redivided into high cardiac output (CO) and low CO groups and measured by EIT at different PEEP levels with a low tidal volume. Additionally, sidestream dark field (SDF) was used to measure pulmonary microcirculation. Hemodynamic parameters and respiratory mechanics parameters were recorded. As PEEP increased at high tidal volume, blood flow was impaired at a higher PEEP (20 cmH2O) compared with low tidal volume (shunt: 30.01 ± 0.69% vs. 17.95 ± 0.72%; V/Q ratio: 65.12 ± 1.97% vs. 76.57 ± 1.25%, p < 0.01). Low tidal volume combined with an appropriate PEEP is the best option from the match between ventilation and pulmonary blood flow. Increasing PEEP can solve the problem of excessive shunt at high CO, and the V/Q ratio tends to match. At low CO, the increased dead space can reach as high as 64.64 ± 7.13% when PEEP = 20 cmH2O. With increasing PEEP, the microcirculation index deteriorates, including total vessel density (TVD), proportion of perfused vessel (PPV), perfused vessel density (PVD), and microcirculatory flow index (MFI). The periodic collapse of pulmonary capillaries or interruption of blood flow obviously occurred with high PEEP. The hemodynamic parameters indicated that the transpulmonary capillary wall pressure (Pcap) of the low CO group was negative at PEEP = 5 cmH2O, which determines the opening and closing of the pulmonary microcirculation and controls lung perfusion and the production of extravascular lung water. Therefore, it is essential to couple macrocirculation and pulmonary microcirculation during mechanical ventilation by improving shunting and optimizing Pcap.
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Affiliation(s)
- Pan Pan
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Lina Li
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Fei Xie
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Xingshuo Hu
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Yinghua Guo
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Lixin Xie
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
- Correspondence: (L.X.); (L.S.)
| | - Longxiang Su
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, 1st Shuaifuyuan, Dongcheng District, Beijing 100730, China
- Correspondence: (L.X.); (L.S.)
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Virsilas E, Liubsys A, Janulionis A, Valiulis A. Noninvasive Respiratory Support Effects on Sighs in Preterm Infants by Electrical Impedance Tomography. Indian J Pediatr 2022:10.1007/s12098-022-04413-8. [PMID: 36539568 DOI: 10.1007/s12098-022-04413-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 10/26/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To evaluate differences regarding sigh frequency between noninvasive respiratory support types and to assess regional ventilation distribution, delta Z, and end-expiratory lung impedance differences before and after sighs. METHODS Very low-birth-weight infants with gestational ages less than 32 wk were included in the study. Participants were split into two groups: those receiving continuous positive airway pressure and infants receiving high-flow nasal cannula therapy. RESULTS The study enrolled 30 infants. The high-flow nasal cannula therapy group had more sighs per 10-min period than infants receiving continuous positive airway pressure (p = 0.016). Ventilation distribution was similar in the anterior and right ventilation distribution compartments pre- and post-sigh (46.30% vs. 45.68% and 54.27% vs. 55.26%, respectively). No statistically significant increase in end-expiratory lung impedance or delta Z was observed in global or separate lung regions (p > 0.05). CONCLUSION The study has demonstrated that sighs are more frequent in infants receiving high-flow nasal cannula respiratory support compared to continuous positive airway pressure. Spontaneously occurring sighs on noninvasive respiratory support due to respiratory distress syndrome (RDS) do not increase end-expiratory lung impedance or alter delta Z, and appear to have limited clinical significance. TRIAL REGISTRATION Prospectively registered at www. CLINICALTRIALS gov , reg. No. NCT04542096, reg. date 01/09/2020.
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Affiliation(s)
- Ernestas Virsilas
- Clinic of Children's Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Santariškių G. 7, 08406, Vilnius, Lithuania.
| | - Arunas Liubsys
- Clinic of Children's Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Santariškių G. 7, 08406, Vilnius, Lithuania
| | - Adomas Janulionis
- Clinic of Children's Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Santariškių G. 7, 08406, Vilnius, Lithuania
| | - Arunas Valiulis
- Clinic of Children's Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Santariškių G. 7, 08406, Vilnius, Lithuania
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Yueyi J, Jing T, Lianbing G. A structured narrative review of clinical and experimental studies of the use of different positive end-expiratory pressure levels during thoracic surgery. THE CLINICAL RESPIRATORY JOURNAL 2022; 16:717-731. [PMID: 36181340 PMCID: PMC9629996 DOI: 10.1111/crj.13545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/03/2022] [Accepted: 09/12/2022] [Indexed: 01/25/2023]
Abstract
OBJECTIVES This study aimed to present a review on the general effects of different positive end-expiratory pressure (PEEP) levels during thoracic surgery by qualitatively categorizing the effects into detrimental, beneficial, and inconclusive. DATA SOURCE Literature search of Pubmed, CNKI, and Wanfang was made to find relative articles about PEEP levels during thoracic surgery. We used the following keywords as one-lung ventilation, PEEP, and thoracic surgery. RESULTS We divide the non-individualized PEEP value into five grades, that is, less than 5, 5, 5-10, 10, and more than 10 cmH2 O, among which 5 cmH2 O is the most commonly used in clinic at present to maintain alveolar dilatation and reduce the shunt fraction and the occurrence of atelectasis, whereas individualized PEEP, adjusted by test titration or imaging method to adapt to patients' personal characteristics, can effectively ameliorate intraoperative oxygenation and obtain optimal pulmonary compliance and better indexes relating to respiratory mechanics. CONCLUSIONS Available data suggest that PEEP might play an important role in one-lung ventilation, the understanding of which will help in exploring a simple and economical method to set the appropriate PEEP level.
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Affiliation(s)
- Jiang Yueyi
- The Affiliated Cancer Hospital of Nanjing Medical UniversityNanjingChina
| | - Tan Jing
- Department of AnesthesiologyJiangsu Cancer HospitalNanjingChina
| | - Gu Lianbing
- The Affiliated Cancer Hospital of Nanjing Medical UniversityNanjingChina,Department of AnesthesiologyJiangsu Cancer HospitalNanjingChina
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7
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Liu JY, Pradhan SH, Hussain S, Sayes CM. Platform for Exposing Aerosolized Substances to Lung Surfactant and Alveolar Cells at the Air-Liquid Interface. ACS CHEMICAL HEALTH & SAFETY 2022. [DOI: 10.1021/acs.chas.2c00033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James Y. Liu
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
| | - Sahar H. Pradhan
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
| | - Saber Hussain
- 711th Human Performance Wing, Air Force Research Laboratory, Dayton, Ohio 45435, United States
| | - Christie M. Sayes
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
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Over-distension prediction via hysteresis loop analysis and patient-specific basis functions in a virtual patient model. Comput Biol Med 2021; 141:105022. [PMID: 34801244 DOI: 10.1016/j.compbiomed.2021.105022] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND OBJECTIVE Recruitment maneuvers (RMs) with subsequent positive-end-expiratory-pressure (PEEP) have proven effective in recruiting lung volume and preventing alveolar collapse. However, a suboptimal PEEP could induce undesired injury in lungs by insufficient or excessive breath support. Thus, a predictive model for patient response under PEEP changes could improve clinical care and lower risks. METHODS This research adds novel elements to a virtual patient model to identify and predict patient-specific lung distension to optimise and personalise care. Model validity and accuracy are validated using data from 18 volume-controlled ventilation (VCV) patients at 7 different baseline PEEP levels (0-12cmH2O), yielding 623 prediction cases. Predictions were made up to ΔPEEP = 12cmH2O ahead covering 6x2cmH2O PEEP steps. RESULTS Using the proposed lung distension model, 90% of absolute peak inspiratory pressure (PIP) prediction errors compared to clinical measurement are within 3.95cmH2O, compared with 4.76cmH2O without this distension term. Comparing model-predicted and clinically measured distension had high correlation increasing to R2 = 0.93-0.95 if maximum ΔPEEP ≤ 6cmH2O. Predicted dynamic functional residual capacity (Vfrc) changes as PEEP rises yield 0.013L median prediction error for both prediction groups and overall R2 of 0.84. CONCLUSIONS Overall results demonstrate nonlinear distension mechanics are accurately captured in virtual lung mechanics patients for mechanical ventilation, for the first time. This result can minimise the risk of lung injury by predicting its potential occurrence of distension before changing ventilator settings. The overall outcomes significantly extend and more fully validate this virtual mechanical ventilation patient model.
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Knopp JL, Chase JG, Kim KT, Shaw GM. Model-based estimation of negative inspiratory driving pressure in patients receiving invasive NAVA mechanical ventilation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 208:106300. [PMID: 34348200 DOI: 10.1016/j.cmpb.2021.106300] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 07/17/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Optimisation of mechanical ventilation (MV) and weaning requires insight into underlying patient breathing effort. Current identifiable models effectively describe lung mechanics, such as elastance (E) and resistance (R) at the bedside in sedated patients, but are less effective when spontaneous breathing is present. This research derives and regularises a single compartment model to identify patient-specific inspiratory effort. METHODS Constrained second-order b-spline basis functions (knot width 0.05 s) are used to describe negative inspiratory drive (Pp, cmH2O) as a function of time. Breath-breath Pp are identified with single E and R values over inspiration and expiration from n = 20 breaths for N = 22 patients on NAVA ventilation. Pp is compared to measured electrical activity of the diaphragm (Eadi) and published results. RESULTS Average per-patient root-mean-squared model fit error was (median [interquartile range, IQR]) 0.9 [0.6-1.3] cmH2O, and average per-patient median Pp was -3.9 [-4.5- -3.0] cmH2O, with range -7.9 - -1.9 cmH2O. Per-patient E and R were 16.4 [13.6-21.8] cmH2O/L and 9.2 [6.4-13.1] cmH2O.s/L, respectively. Most patients showed an inspiratory volume threshold beyond which Pp started to return to baseline, and Pp at peak Eadi (end-inspiration) was often strongly correlated with peak Eadi (R2=0.25-0.86). Similarly, average transpulmonary pressure was consistent breath-breath in most patients, despite differences in peak Eadi and thus peak airway pressure. CONCLUSIONS The model-based inspiratory effort aligns with electrical muscle activity and published studies showing neuro-muscular decoupling as a function of pressure and/or volume. Consistency in coupling/dynamics were patient-specific. Quantification of patient and ventilator work of breathing contributions may aid optimisation of MV modes and weaning.
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Affiliation(s)
- Jennifer L Knopp
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
| | - J Geoffrey Chase
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Kyeong Tae Kim
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Geoffrey M Shaw
- Department of Intensive Care, Christchurch Hospital, Private Bag 4710, Christchurch, New Zealand
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Yang YC, Huai Q, Cui SZ, Cao XW, Gao BL. Effects of inverse ratio ventilation combined with lung protective ventilation on pulmonary function in patients with severe burns for surgery. Libyan J Med 2021; 15:1767276. [PMID: 32441571 PMCID: PMC7654640 DOI: 10.1080/19932820.2020.1767276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Objective To investigate the effects of inverse ratio ventilation combined with lung-protective ventilation on pulmonary function and inflammatory factors in severe burn patients undergoing surgery. Populations and Methods: Eighty patients with severe burns undergoing elective surgery were divided randomly into two groups: control (CG, n = 40) and experiment (EG, n = 40). The CG had conventional ventilation, whereas the EG were ventilated with tidal volume (TV) of 6–8 ml/kg, I (inspiration): E (expiration) of 2:1, and positive end-expiratory pressure (PEEP) 5 cm H2O. The following variables were evaluated before (T0), 1 h after start of surgery (T1) and after surgery (T2): oxygenation index (OI), partial pressure of carbon dioxide (PaCO2), TV, peak airway pressure (Ppeak), mean airway pressure (Pmean), PEEP, pulmonary dynamic compliance (Cdyn), alveolar–arterial difference of oxygen partial pressure D(A-a)O2, lactic acid (Lac), interleukin (IL)-6 and IL-10, and lung complications. Results: At T1 and T2 time points, the OI, Pmean and Cdyn were significantly greater in the EG than in the CG while the TV, Ppeak, D(A-a)O2, IL-6 and IL-10 were significantly smaller in the EG than in the CG. At the end of the surgery, the Lac was significantly smaller in the EG than in the CG (1.28 ± 0.19 vs. 1.40 ± 0.23 mmol/L). Twenty-four hours after the surgery, significantly more patients had hypoxemia (27.5 vs. 10.0%), increased expectoration (45.0 vs. 22.5%), increased lung texture or exudation (37.5 vs. 17.5%) in the CG than in the EG. Conclusions: Inverse ratio ventilation combined with lung-protective ventilation can reduce Ppeak, increase Pmean and Cdyn, improve the pulmonary oxygenation function, and decrease ILs in severe burn surgery patients.
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Affiliation(s)
- Yan-Chao Yang
- Department of Anesthesiology, Shijiazhuang First Hospital, Hebei Medical University , Shijiazhuang, Hebei Province, China
| | - Qiao Huai
- Department of Anesthesiology, Shijiazhuang First Hospital, Hebei Medical University , Shijiazhuang, Hebei Province, China
| | - Shu-Zhen Cui
- Department of Anesthesiology, Shijiazhuang First Hospital, Hebei Medical University , Shijiazhuang, Hebei Province, China
| | - Xiao-Wei Cao
- Respiratory Department, Shijiazhuang First Hospital, Hebei Medical University , Shijiazhuang, Hebei Province, China
| | - Bu-Lang Gao
- Department of Anesthesiology, Shijiazhuang First Hospital, Hebei Medical University , Shijiazhuang, Hebei Province, China
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Nishikimi M, Nishida K, Shindo Y, Shoaib M, Kasugai D, Yasuda Y, Higashi M, Numaguchi A, Yamamoto T, Matsui S, Matsuda N. Failure of non-invasive respiratory support after 6 hours from initiation is associated with ICU mortality. PLoS One 2021; 16:e0251030. [PMID: 33930089 PMCID: PMC8087003 DOI: 10.1371/journal.pone.0251030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 04/19/2021] [Indexed: 12/28/2022] Open
Abstract
A previous study has shown that late failure (> 48 hours) of high-flow nasal cannula (HFNC) was associated with intensive care unit (ICU) mortality. The aim of this study was to investigate whether failure of non-invasive respiratory support, including HFNC and non-invasive positive pressure ventilation (NPPV), was also associated with the risk of mortality even if it occurs in the earlier phase. We retrospectively analyzed 59 intubated patients for acute respiratory failure due to lung diseases between April 2014 and June 2018. We divided the patients into 2 groups according to the time from starting non-invasive ventilatory support until their intubation: ≤ 6 hours failure and > 6 hours failure group. We evaluated the differences in the ICU mortality between these two groups. The multivariate logistic regression analysis showed the highest mortality in the > 6 hours failure group as compared to the ≤ 6 hours failure group, with a statistically significant difference (p < 0.01). It was also associated with a statistically significant increased 30-day mortality and decreased ventilator weaning rate. The ICU mortality in patients with acute respiratory failure caused by lung diseases was increased if the time until failure of HFNC and NPPV was more than 6 hours.
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Affiliation(s)
- Mitsuaki Nishikimi
- Department of Emergency and Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Emergency Medicine, Northwell Health, NY, NY, United States of America
- Laboratory for Critical Care Physiology at the Feinstein Institutes for Medical Research, Northwell Health, NY, NY, United States of America
- * E-mail:
| | - Kazuki Nishida
- Department of Biostatistics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yuichiro Shindo
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Muhammad Shoaib
- Laboratory for Critical Care Physiology at the Feinstein Institutes for Medical Research, Northwell Health, NY, NY, United States of America
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States of America
| | - Daisuke Kasugai
- Department of Emergency and Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yuma Yasuda
- Department of Emergency and Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Michiko Higashi
- Department of Emergency and Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Atsushi Numaguchi
- Department of Emergency and Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takanori Yamamoto
- Department of Emergency and Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shigeyuki Matsui
- Department of Biostatistics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Naoyuki Matsuda
- Department of Emergency and Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
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12
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Commentary: The tid(al)s are turning toward lower volumes. J Thorac Cardiovasc Surg 2021; 163:1587-1588. [PMID: 33676758 DOI: 10.1016/j.jtcvs.2021.01.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 01/10/2021] [Accepted: 01/11/2021] [Indexed: 11/22/2022]
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13
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Tidal volume during 1-lung ventilation: A systematic review and meta-analysis. J Thorac Cardiovasc Surg 2020; 163:1573-1585.e1. [PMID: 33518385 DOI: 10.1016/j.jtcvs.2020.12.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 11/20/2020] [Accepted: 12/07/2020] [Indexed: 11/23/2022]
Abstract
BACKGROUND The selection of tidal volumes for 1-lung ventilation remains unclear, because there exists a trade-off between oxygenation and risk of lung injury. We conducted a systematic review and meta-analysis to determine how oxygenation, compliance, and clinical outcomes are affected by tidal volume during 1-lung ventilation. METHODS A systematic search of MEDLINE and EMBASE was performed. A systematic review and random-effects meta-analysis was conducted. Pooled mean difference estimated arterial oxygen tension, compliance, and length of stay; pooled odds ratio was calculated for composite postoperative pulmonary complications. Risk of bias was determined using the Cochrane risk of bias and Newcastle-Ottawa tools. RESULTS Eighteen studies were identified, comprising 3693 total patients. Low tidal volumes (5.6 [±0.9] mL/kg) were not associated with significant differences in partial pressure of oxygen (-15.64 [-88.53-57.26] mm Hg; P = .67), arterial oxygen tension to fractional intake of oxygen ratio (14.71 [-7.83-37.24]; P = .20), or compliance (2.03 [-5.22-9.27] mL/cmH2O; P = .58) versus conventional tidal volume ventilation (8.1 [±3.1] mL/kg). Low versus conventional tidal volume ventilation had no significant impact on hospital length of stay (-0.42 [-1.60-0.77] days; P = .49). Low tidal volumes are associated with significantly decreased odds of pulmonary complications (pooled odds ratio, 0.40 [0.29-0.57]; P < .0001). CONCLUSIONS Low tidal volumes during 1-lung ventilation do not worsen oxygenation or compliance. A low tidal volume ventilation strategy during 1-lung ventilation was associated with a significant reduction in postoperative pulmonary complications.
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Foley TM, Philpot BA, Davis AS, Swanson MB, Harland KK, Kuhn JD, Fuller BM, Mohr NM. Implementation of an ED-based bundled mechanical ventilation protocol improves adherence to lung-protective ventilation. Am J Emerg Med 2020; 43:186-194. [PMID: 32139215 PMCID: PMC7483340 DOI: 10.1016/j.ajem.2020.02.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 02/11/2020] [Accepted: 02/25/2020] [Indexed: 11/05/2022] Open
Affiliation(s)
- Tyler M Foley
- Department of Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America.
| | - Brittany A Philpot
- Department of Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Alysa S Davis
- Department of Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Morgan B Swanson
- Department of Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Karisa K Harland
- Department of Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Justin D Kuhn
- Department of Respiratory Care, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Brian M Fuller
- Division of Emergency Medicine, Department of Anesthesiology, Division of Critical Care, Washington University School of Medicine in St. Louis, St. Louis, MO, United States of America
| | - Nicholas M Mohr
- Department of Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Division of Critical Care, Department of Anesthesia, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
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Yehya N. Lessons learned in acute respiratory distress syndrome from the animal laboratory. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:503. [PMID: 31728356 DOI: 10.21037/atm.2019.09.33] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Since the description of the acute respiratory distress syndrome (ARDS) in 1967, investigators have struggled to reproduce the syndrome in the animal laboratory. While several different models of experimental acute lung injury (ALI) have been developed, none completely capture the inciting etiologies, initial inflammation, heterogeneity, and resolution of human ARDS. This potentially has contributed to the poor translation of potential therapeutics between animal ALI models and human ARDS. It was only recently that standardized criteria were suggested for what makes an ALI model comparable to human ARDS. Nevertheless, despite model heterogeneity, these models have contributed substantially to our understanding of the syndrome. From the initial studies identifying the risks of mechanical ventilation to the identification of potentially targetable inflammatory mediators, to modern studies focusing on regional heterogeneity and novel molecular pathways, animal models continue to inform our understanding of ARDS. This review will cover several major lessons learned from animal models of ALI, and provide some direction for future studies in this field.
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Affiliation(s)
- Nadir Yehya
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, USA
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16
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Bitker L, Costes N, Le Bars D, Lavenne F, Orkisz M, Hernandez Hoyos M, Benzerdjeb N, Devouassoux M, Richard JC. Noninvasive quantification of macrophagic lung recruitment during experimental ventilation-induced lung injury. J Appl Physiol (1985) 2019; 127:546-558. [PMID: 31169472 DOI: 10.1152/japplphysiol.00825.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Macrophagic lung infiltration is pivotal in the development of lung biotrauma because of ventilation-induced lung injury (VILI). We assessed the performance of [11C](R)-PK11195, a positron emission tomography (PET) radiotracer binding the translocator protein, to quantify macrophage lung recruitment during experimental VILI. Pigs (n = 6) were mechanically ventilated under general anesthesia, using protective ventilation settings (baseline). Experimental VILI was performed by titrating tidal volume to reach a transpulmonary end-inspiratory pressure (∆PL) of 35-40 cmH2O. We acquired PET/computed tomography (CT) lung images at baseline and after 4 h of VILI. Lung macrophages were quantified in vivo by the standardized uptake value (SUV) of [11C](R)-PK11195 measured in PET on the whole lung and in six lung regions and ex vivo on lung pathology at the end of experiment. Lung mechanics were extracted from CT images to assess their association with the PET signal. ∆PL increased from 9 ± 1 cmH2O under protective ventilation, to 36 ± 6 cmH2O during experimental VILI. Compared with baseline, whole-lung [11C](R)-PK11195 SUV significantly increased from 1.8 ± 0.5 to 2.9 ± 0.5 after experimental VILI. Regional [11C](R)-PK11195 SUV was positively associated with the magnitude of macrophage recruitment in pathology (P = 0.03). Compared with baseline, whole-lung CT-derived dynamic strain and tidal hyperinflation increased significantly after experimental VILI, from 0.6 ± 0 to 2.0 ± 0.4, and 1 ± 1 to 43 ± 19%, respectively. On multivariate analysis, both were significantly associated with regional [11C](R)-PK11195 SUV. [11C](R)-PK11195 lung uptake (a proxy of lung inflammation) was increased by experimental VILI and was associated with the magnitude of dynamic strain and tidal hyperinflation.NEW & NOTEWORTHY We assessed the performance of [11C](R)-PK11195, a translocator protein-specific positron emission tomography (PET) radiotracer, to quantify macrophage lung recruitment during experimental ventilation-induced lung injury (VILI). In this proof-of-concept study, we showed that the in vivo quantification of [11C](R)-PK11195 lung uptake in PET reflected the magnitude of macrophage lung recruitment after VILI. Furthermore, increased [11C](R)-PK11195 lung uptake was associated with harmful levels of dynamic strain and tidal hyperinflation applied to the lungs.
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Affiliation(s)
- Laurent Bitker
- Service de Médecine Intensive et Réanimation, Hôpital de la Croix Rousse, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, CREATIS Unité Mixte de Recherche 5220, U1206, Villeurbanne, France.,Université Lyon 1 Claude Bernard, Université de Lyon, Lyon, France
| | | | - Didier Le Bars
- Université Lyon 1 Claude Bernard, Université de Lyon, Lyon, France.,CERMEP - Imagerie du Vivant, Bron, France
| | | | - Maciej Orkisz
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, CREATIS Unité Mixte de Recherche 5220, U1206, Villeurbanne, France.,Université Lyon 1 Claude Bernard, Université de Lyon, Lyon, France
| | - Marcela Hernandez Hoyos
- Systems and Computing Engineering Department, School of Engineering, Universidad de los Andes, Bogota, Colombia
| | - Nazim Benzerdjeb
- Université Lyon 1 Claude Bernard, Université de Lyon, Lyon, France.,Centre d'Anatomie et Cytologie Pathologique, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, Lyon, France
| | - Mojgan Devouassoux
- Université Lyon 1 Claude Bernard, Université de Lyon, Lyon, France.,Centre d'Anatomie et Cytologie Pathologique, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, Lyon, France
| | - Jean-Christophe Richard
- Service de Médecine Intensive et Réanimation, Hôpital de la Croix Rousse, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, CREATIS Unité Mixte de Recherche 5220, U1206, Villeurbanne, France.,Université Lyon 1 Claude Bernard, Université de Lyon, Lyon, France
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LIU TIANYA, WANG YUXING, LIU XIAOYU, YUAN LAN, LI DEYU, QIAO HUITING, FAN YUBO. EFFECTS OF ALVEOLAR MORPHOLOGY ON ALVEOLAR MECHANICS: AN EXPERIMENTAL STUDY OF MOUSE LUNG BASED ON TWO- AND THREE-DIMENSIONAL IMAGING METHODS. J MECH MED BIOL 2019. [DOI: 10.1142/s0219519419500271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Understanding alveolar mechanics is important for preventing the possible lung injuries during mechanical ventilation. Alveolar clusters with smaller size are found having lower compliance in two-dimensional studies. But the influence of alveolar shape on compliance is unclear. In order to investigate how alveolar morphology affects their behavior, we tracked subpleural alveoli of isolated mouse lungs during quasi-static ventilation using two- and three-dimensional imaging techniques. Results showed that alveolar clusters with smaller size and more spherical shape had lower compliance. There was a better correlation of sphericity rather than circularity with alveolar compliance. The compliance of clusters with great shape change was larger than that with relatively slight shape change. These findings suggest the contribution of lung heterogeneous expansion to lung injuries associated with mechanical ventilation.
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Affiliation(s)
- TIANYA LIU
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - YUXING WANG
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - XIAOYU LIU
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - LAN YUAN
- Beijing Key Laboratory of Rehabilitation Engineering for Elderly, National Research Center for Rehabilitation Technical Aids, Beijing 100176, P. R. China
| | - DEYU LI
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - HUITING QIAO
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - YUBO FAN
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
- Medical and Health Analysis Center, Peking University, Beijing 100191, P. R. China
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Effects of pressure support ventilation on ventilator-induced lung injury in mild acute respiratory distress syndrome depend on level of positive end-expiratory pressure: A randomised animal study. Eur J Anaesthesiol 2019; 35:298-306. [PMID: 29324568 DOI: 10.1097/eja.0000000000000763] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Harmful effects of spontaneous breathing have been shown in experimental severe acute respiratory distress syndrome (ARDS). However, in the clinical setting, spontaneous respiration has been indicated only in mild ARDS. To date, no study has compared the effects of spontaneous assisted breathing with those of fully controlled mechanical ventilation at different levels of positive end-expiratory pressure (PEEP) on lung injury in ARDS. OBJECTIVE To compare the effects of assisted pressure support ventilation (PSV) with pressure-controlled ventilation (PCV) on lung function, histology and biological markers at two different PEEP levels in mild ARDS in rats. DESIGN Randomised controlled experimental study. SETTING Basic science laboratory. PARTICIPANTS Thirty-five Wistar rats (weight ± SD, 310 ± 19) g received Escherichia coli lipopolysaccharide (LPS) intratracheally. After 24 h, the animals were anaesthetised and randomly allocated to either PCV (n=14) or PSV (n=14) groups. Each group was further assigned to PEEP = 2 cmH2O or PEEP = 5 cmH2O. Tidal volume was kept constant (≈6 ml kg). Additional nonventilated animals (n=7) were used as a control for postmortem analysis. MAIN OUTCOME MEASURES Ventilatory and mechanical parameters, arterial blood gases, diffuse alveolar damage score, epithelial integrity measured by E-cadherin tissue expression, and biological markers associated with inflammation (IL-6 and cytokine-induced neutrophil chemoattractant, CINC-1) and type II epithelial cell damage (surfactant protein-B) were evaluated. RESULTS In both PCV and PSV, peak transpulmonary pressure was lower, whereas E-cadherin tissue expression, which is related to epithelial integrity, was higher at PEEP = 5 cmH2O than at PEEP = 2 cmH2O. In PSV, PEEP = 5 cmH2O compared with PEEP = 2 cmH2O was associated with significantly reduced diffuse alveolar damage score [median (interquartile range), 11 (8.5 to 13.5) vs. 23 (19 to 26), P = 0.005] and expressions of IL-6 and CINC-1 (P = 0.02 for both), whereas surfactant protein-B mRNA expression increased (P = 0.03). These changes suggested less type II epithelial cell damage at a PEEP of 5 cmH2O. Peak transpulmonary pressure correlated positively with IL-6 [Spearman's rho (ρ) = 0.62, P = 0.0007] and CINC-1 expressions (ρ = 0.50, P = 0.01) and negatively with E-cadherin expression (ρ = -0.67, P = 0.0002). CONCLUSION During PSV, PEEP of 5 cmH2O, but not a PEEP of 2 cmH2O, reduced lung damage and inflammatory markers while maintaining epithelial cell integrity.
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19
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The Basic Science and Molecular Mechanisms of Lung Injury and Acute Respiratory Distress Syndrome. Int Anesthesiol Clin 2019; 56:1-25. [PMID: 29227309 DOI: 10.1097/aia.0000000000000177] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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20
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Continuous Negative Abdominal Pressure Reduces Ventilator-induced Lung Injury in a Porcine Model. Anesthesiology 2019; 129:163-172. [PMID: 29708892 DOI: 10.1097/aln.0000000000002236] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND In supine patients with acute respiratory distress syndrome, the lung typically partitions into regions of dorsal atelectasis and ventral aeration ("baby lung"). Positive airway pressure is often used to recruit atelectasis, but often overinflates ventral (already aerated) regions. A novel approach to selective recruitment of dorsal atelectasis is by "continuous negative abdominal pressure." METHODS A randomized laboratory study was performed in anesthetized pigs. Lung injury was induced by surfactant lavage followed by 1 h of injurious mechanical ventilation. Randomization (five pigs in each group) was to positive end-expiratory pressure (PEEP) alone or PEEP with continuous negative abdominal pressure (-5 cm H2O via a plexiglass chamber enclosing hindlimbs, pelvis, and abdomen), followed by 4 h of injurious ventilation (high tidal volume, 20 ml/kg; low expiratory transpulmonary pressure, -3 cm H2O). The level of PEEP at the start was ≈7 (vs. ≈3) cm H2O in the PEEP (vs. PEEP plus continuous negative abdominal pressure) groups. Esophageal pressure, hemodynamics, and electrical impedance tomography were recorded, and injury determined by lung wet/dry weight ratio and interleukin-6 expression. RESULTS All animals survived, but cardiac output was decreased in the PEEP group. Addition of continuous negative abdominal pressure to PEEP resulted in greater oxygenation (PaO2/fractional inspired oxygen 316 ± 134 vs. 80 ± 24 mmHg at 4 h, P = 0.005), compliance (14.2 ± 3.0 vs. 10.3 ± 2.2 ml/cm H2O, P = 0.049), and homogeneity of ventilation, with less pulmonary edema (≈10% less) and interleukin-6 expression (≈30% less). CONCLUSIONS Continuous negative abdominal pressure added to PEEP reduces ventilator-induced lung injury in a pig model compared with PEEP alone, despite targeting identical expiratory transpulmonary pressure.
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Knudsen L, Lopez-Rodriguez E, Berndt L, Steffen L, Ruppert C, Bates JHT, Ochs M, Smith BJ. Alveolar Micromechanics in Bleomycin-induced Lung Injury. Am J Respir Cell Mol Biol 2018; 59:757-769. [PMID: 30095988 PMCID: PMC6293074 DOI: 10.1165/rcmb.2018-0044oc] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 06/29/2018] [Indexed: 12/22/2022] Open
Abstract
Lung injury results in intratidal alveolar recruitment and derecruitment and alveolar collapse, creating stress concentrators that increase strain and aggravate injury. In this work, we sought to describe alveolar micromechanics during mechanical ventilation in bleomycin-induced lung injury and surfactant replacement therapy. Structure and function were assessed in rats 1 day and 3 days after intratracheal bleomycin instillation and after surfactant replacement therapy. Pulmonary system mechanics were measured during ventilation with positive end-expiratory pressures (PEEPs) between 1 and 10 cm H2O, followed by perfusion fixation at end-expiratory pressure at airway opening (Pao) values of 1, 5, 10, and 20 cm H2O for quantitative analyses of lung structure. Lung structure and function were used to parameterize a physiologically based, multicompartment computational model of alveolar micromechanics. In healthy controls, the numbers of open alveoli remained stable in a range of Pao = 1-20 cm H2O, whereas bleomycin-challenged lungs demonstrated progressive alveolar derecruitment with Pao < 10 cm H2O. At Day 3, ∼40% of the alveoli remained closed at high Pao, and alveolar size heterogeneity increased. Simulations of injured lungs predicted that alveolar recruitment pressures were much greater than the derecruitment pressures, so that minimal intratidal recruitment and derecruitment occurred during mechanical ventilation with a tidal volume of 10 ml/kg body weight over a range of PEEPs. However, the simulations also predicted a dramatic increase in alveolar strain with injury that we attribute to alveolar interdependence. These findings suggest that in progressive lung injury, alveolar collapse with increased distension of patent (open) alveoli dominates alveolar micromechanics. PEEP and surfactant substitution reduce alveolar collapse and dynamic strain but increase static strain.
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Affiliation(s)
- Lars Knudsen
- Institute of Functional and Applied Anatomy, and
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research (DZL) Hannover Medical School, Hannover, Germany
- REBIRTH, Cluster of Excellence, Hannover, Germany
| | - Elena Lopez-Rodriguez
- Institute of Functional and Applied Anatomy, and
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research (DZL) Hannover Medical School, Hannover, Germany
- REBIRTH, Cluster of Excellence, Hannover, Germany
| | | | | | - Clemens Ruppert
- Department of Internal Medicine, and
- Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research (DZL), Justus Liebig University Giessen, Giessen, Germany
| | | | - Matthias Ochs
- Institute of Functional and Applied Anatomy, and
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research (DZL) Hannover Medical School, Hannover, Germany
- REBIRTH, Cluster of Excellence, Hannover, Germany
| | - Bradford J. Smith
- Department of Bioengineering, University of Colorado Denver, Denver, Colorado
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Blankman P, Shono A, Hermans BJM, Wesselius T, Hasan D, Gommers D. Detection of optimal PEEP for equal distribution of tidal volume by volumetric capnography and electrical impedance tomography during decreasing levels of PEEP in post cardiac-surgery patients. Br J Anaesth 2018; 116:862-9. [PMID: 27199318 PMCID: PMC4872863 DOI: 10.1093/bja/aew116] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2016] [Indexed: 01/26/2023] Open
Abstract
Background Homogeneous ventilation is important for prevention of ventilator-induced lung injury. Electrical impedance tomography (EIT) has been used to identify optimal PEEP by detection of homogenous ventilation in non-dependent and dependent lung regions. We aimed to compare the ability of volumetric capnography and EIT in detecting homogenous ventilation between these lung regions. Methods Fifteen mechanically-ventilated patients after cardiac surgery were studied. Ventilator settings were adjusted to volume-controlled mode with a fixed tidal volume (Vt) of 6–8 ml kg−1 predicted body weight. Different PEEP levels were applied (14 to 0 cm H2O, in steps of 2 cm H2O) and blood gases, Vcap and EIT were measured. Results Tidal impedance variation of the non-dependent region was highest at 6 cm H2O PEEP, and decreased significantly at 14 cm H2O PEEP indicating decrease in the fraction of Vt in this region. At 12 cm H2O PEEP, homogenous ventilation was seen between both lung regions. Bohr and Enghoff dead space calculations decreased from a PEEP of 10 cm H2O. Alveolar dead space divided by alveolar Vt decreased at PEEP levels ≤6 cm H2O. The normalized slope of phase III significantly changed at PEEP levels ≤4 cm H2O. Airway dead space was higher at higher PEEP levels and decreased at the lower PEEP levels. Conclusions In postoperative cardiac patients, calculated dead space agreed well with EIT to detect the optimal PEEP for an equal distribution of inspired volume, amongst non-dependent and dependent lung regions. Airway dead space reduces at decreasing PEEP levels.
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Affiliation(s)
- P Blankman
- Department of Adult Intensive Care, Erasmus MC, Room H623, 's Gravendijkwal 230, Rotterdam 3015 CE, The Netherlands
| | - A Shono
- Department of Adult Intensive Care, Erasmus MC, Room H623, 's Gravendijkwal 230, Rotterdam 3015 CE, The Netherlands
| | - B J M Hermans
- Institute for Biomedical Technology & Technical Medicine, University of Twente, Enschede, The Netherlands
| | - T Wesselius
- Institute for Biomedical Technology & Technical Medicine, University of Twente, Enschede, The Netherlands
| | - D Hasan
- Department of Adult Intensive Care, Erasmus MC, Room H623, 's Gravendijkwal 230, Rotterdam 3015 CE, The Netherlands Institute for Immunotherapy, Duderstadt, Germany
| | - D Gommers
- Department of Adult Intensive Care, Erasmus MC, Room H623, 's Gravendijkwal 230, Rotterdam 3015 CE, The Netherlands
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23
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Bhatia R, Davis PG, Tingay DG. Regional Volume Characteristics of the Preterm Infant Receiving First Intention Continuous Positive Airway Pressure. J Pediatr 2017; 187:80-88.e2. [PMID: 28545875 DOI: 10.1016/j.jpeds.2017.04.046] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/27/2017] [Accepted: 04/21/2017] [Indexed: 01/19/2023]
Abstract
OBJECTIVE To determine whether applying nasal continuous positive airway pressure (CPAP) using systematic changes in continuous distending pressure (CDP) results in a quasi-static pressure-volume relationship in very preterm infants receiving first intention CPAP in the first 12-18 hours of life. STUDY DESIGN Twenty infants at <32 weeks' gestation with mild respiratory distress syndrome (RDS) managed exclusively with nasal CPAP had CDP increased from 5 to 8 to 10 cmH2O, and then decreased to 8 cmH2O and returned to baseline CDP. Each CDP was maintained for 20 min. At each CDP, relative impedance change in end-expiratory thoracic volume (ΔZEEV) and tidal volume (ΔZVT) were measured using electrical impedance tomography. Esophageal pressure (Poes) was measured as a proxy for intrapleural pressure to determine transpulmonary pressure (Ptp). RESULTS Overall, there was a relationship between Ptp and global ΔZEEV representing the pressure-volume relationship in the lungs. There were regional variations in ΔZEEV, with 13 infants exhibiting hysteresis with the greatest gains in EEV and tidal volume in the dependent lung with no hemodynamic compromise. Seven infants did not demonstrate hysteresis during decremental CDP changes. CONCLUSION It was possible to define a pressure-volume relationship of the lung and demonstrate reversal of atelectasis by systematically manipulating CDP in most very preterm infants with mild RDS. This suggests that CDP manipulation can be used to optimize the volume state of the preterm lung.
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Affiliation(s)
- Risha Bhatia
- Newborn Research, The Royal Women's Hospital, Melbourne, Australia; Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia; The University of Melbourne, Melbourne, Australia; Monash Newborn, Monash Children's Hospital, Melbourne, Australia.
| | - Peter G Davis
- Newborn Research, The Royal Women's Hospital, Melbourne, Australia; Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia; The University of Melbourne, Melbourne, Australia
| | - David G Tingay
- Newborn Research, The Royal Women's Hospital, Melbourne, Australia; Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia; The University of Melbourne, Melbourne, Australia; Department of Neonatology, The Royal Children's Hospital, Melbourne, Australia
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24
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Management of One-lung Ventilation: Impact of Tidal Volume on Complications after Thoracic Surgery. Anesthesiology 2017; 124:1286-95. [PMID: 27011307 DOI: 10.1097/aln.0000000000001100] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND The use of lung-protective ventilation (LPV) strategies may minimize iatrogenic lung injury in surgical patients. However, the identification of an ideal LPV strategy, particularly during one-lung ventilation (OLV), remains elusive. This study examines the role of ventilator management during OLV and its impact on clinical outcomes. METHODS Data were retrospectively collected from the hospital electronic medical record and the Society of Thoracic Surgery database for subjects undergoing thoracic surgery with OLV between 2012 and 2014. Mean tidal volume (VT) during two-lung ventilation and OLV and ventilator driving pressure (ΔP) (plateau pressure - positive end-expiratory pressure [PEEP]) were analyzed for the 1,019 cases that met the inclusion criteria. Associations between ventilator parameters and clinical outcomes were examined by multivariate linear regression. RESULTS After the initiation of OLV, 73.3, 43.3, 18.8, and 7.2% of patients received VT greater than 5, 6, 7, and 8 ml/kg predicted body weight, respectively. One hundred and eighty-four primary and 288 secondary outcome events were recorded. In multivariate logistic regression modeling, VT was inversely related to the incidence of respiratory complications (odds ratio, 0.837; 95% CI, 0.729 to 0.958), while ΔP predicted the development of major morbidity when modeled with VT (odds ratio, 1.034; 95% CI, 1.001 to 1.068). CONCLUSIONS Low VT per se (i.e., in the absence of sufficient PEEP) has not been unambiguously demonstrated to be beneficial. The authors found that a large proportion of patients continue to receive high VT during OLV and that VT was inversely related to the incidence of respiratory complications and major postoperative morbidity. While low (physiologically appropriate) VT is an important component of an LPV strategy for surgical patients during OLV, current evidence suggests that, without adequate PEEP, low VT does not prevent postoperative respiratory complications. Thus, use of physiologic VT may represent a necessary, but not independently sufficient, component of LPV.
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Amado-Rodríguez L, Del Busto C, García-Prieto E, Albaiceta GM. Mechanical ventilation in acute respiratory distress syndrome: The open lung revisited. Med Intensiva 2017; 41:550-558. [PMID: 28238441 DOI: 10.1016/j.medin.2016.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 12/26/2016] [Indexed: 02/02/2023]
Abstract
Acute respiratory distress syndrome (ARDS) is still related to high mortality and morbidity rates. Most patients with ARDS will require ventilatory support. This treatment has a direct impact upon patient outcome and is associated to major side effects. In this regard, ventilator-associated lung injury (VALI) is the main concern when this technique is used. The ultimate mechanisms of VALI and its management are under constant evolution. The present review describes the classical mechanisms of VALI and how they have evolved with recent findings from physiopathological and clinical studies, with the aim of analyzing the clinical implications derived from them. Lastly, a series of knowledge-based recommendations are proposed that can be helpful for the ventilator assisted management of ARDS at the patient bedside.
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Affiliation(s)
- L Amado-Rodríguez
- Unidad de Gestión Clínica de Medicina Intensiva, Hospital Valle del Nalón, Langreo, Spain
| | - C Del Busto
- Unidad de Cuidados Intensivos Cardiológicos, Hospital Universitario Central de Asturias, Oviedo, Spain
| | - E García-Prieto
- Servicio de Medicina Intensiva, Hospital Universitario Central de Asturias, Oviedo, Spain
| | - G M Albaiceta
- Unidad de Cuidados Intensivos Cardiológicos, Hospital Universitario Central de Asturias, Oviedo, Spain; Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Oviedo, Spain.
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Tabuchi A, Nickles HT, Kim M, Semple JW, Koch E, Brochard L, Slutsky AS, Pries AR, Kuebler WM. Acute Lung Injury Causes Asynchronous Alveolar Ventilation That Can Be Corrected by Individual Sighs. Am J Respir Crit Care Med 2016; 193:396-406. [PMID: 26513710 DOI: 10.1164/rccm.201505-0901oc] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
RATIONALE Improved ventilation strategies have been the mainstay for reducing mortality in acute respiratory distress syndrome. Their unique clinical effectiveness is, however, unmatched by our understanding of the underlying mechanobiology, and their impact on alveolar dynamics and gas exchange remains largely speculative. OBJECTIVES To assess changes in alveolar dynamics and associated effects on local gas exchange in experimental models of acute lung injury (ALI) and their responsiveness to sighs. METHODS Alveolar dynamics and local gas exchange were studied in vivo by darkfield microscopy and multispectral oximetry in experimental murine models of ALI induced by hydrochloric acid, Tween instillation, or in antibody-mediated transfusion-related ALI. MEASUREMENTS AND MAIN RESULTS Independent of injury mode, ALI resulted in asynchronous alveolar ventilation characteristic of alveolar pendelluft, which either spontaneously resolved or progressed to a complete cessation or even inversion of alveolar ventilation. The functional relevance of the latter phenomena was evident as impaired blood oxygenation in juxtaposed lung capillaries. Individual sighs (2 × 10 s at inspiratory plateau pressure of 30 cm H2O) largely restored normal alveolar dynamics and gas exchange in acid-induced ALI, yet not in Tween-induced surfactant depletion. CONCLUSIONS We describe for the first time in detail the different forms and temporal sequence of impaired alveolar dynamics in the acutely injured lung and report the first direct visualization of alveolar pendelluft. Moreover, we identify individual sighs as an effective strategy to restore intact alveolar ventilation by a mechanism independent of alveolar collapse and reopening.
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Affiliation(s)
- Arata Tabuchi
- 1 Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Hannah T Nickles
- 2 Institute of Physiology, Charité-Universitätsmedizin, Berlin, Germany
| | - Michael Kim
- 1 Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
| | - John W Semple
- 1 Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,3 Department of Pharmacology.,4 Department of Medicine.,5 Department of Laboratory Medicine and Pathobiology
| | - Edmund Koch
- 6 Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Medical Faculty of the Technical University, Dresden, Germany; and
| | - Laurent Brochard
- 1 Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,7 Interdepartmental Division of Critical Care Medicine
| | - Arthur S Slutsky
- 1 Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,7 Interdepartmental Division of Critical Care Medicine
| | - Axel R Pries
- 2 Institute of Physiology, Charité-Universitätsmedizin, Berlin, Germany
| | - Wolfgang M Kuebler
- 1 Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,2 Institute of Physiology, Charité-Universitätsmedizin, Berlin, Germany.,8 Department of Surgery, and.,9 Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,10 German Heart Institute, Berlin, Germany
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Jauncey-Cooke J, Schibler A, Bogossian F, Gibbons K, Grant CA, East CE. Lung recruitment manoeuvres in mechanically ventilated children for reducing respiratory morbidity. Hippokratia 2016. [DOI: 10.1002/14651858.cd008866.pub2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Andreas Schibler
- Mater Children’s Hospital; Paediatric Critical Care Research Group; South Brisbane Queensland Australia 4101
| | - Fiona Bogossian
- School of Nursing and Midwifery; The University of Queensland; Herston Australia
| | - Kristen Gibbons
- Mater Research Institute; South Brisbane Queensland Australia 4101
| | - Caroline A Grant
- Mater Children's Hospital; Paediatric Intensive Care Unit; Raymond Terrace South Brisbane Queensland Australia 4001
| | - Christine E East
- Monash University/Monash Health; School of Nursing and Midwifery/Maternity Services; 246 Clayton Road Clayton Victoria Australia 3168
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Retamal J, Bugedo G, Larsson A, Bruhn A. High PEEP levels are associated with overdistension and tidal recruitment/derecruitment in ARDS patients. Acta Anaesthesiol Scand 2015; 59:1161-9. [PMID: 26061818 DOI: 10.1111/aas.12563] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 04/28/2015] [Accepted: 04/30/2015] [Indexed: 01/14/2023]
Abstract
BACKGROUND Positive end-expiratory pressure (PEEP) improves gas exchange and respiratory mechanics, and it may decrease tissue injury and inflammation. The mechanisms of this protective effect are not fully elucidated. Our aim was to determine the intrinsic effects of moderate and higher levels of PEEP on tidal recruitment/derecruitment, hyperinflation, and lung mechanics, in patients with acute respiratory distress syndrome (ARDS). METHODS Nine patients with ARDS of mainly pulmonary origin were ventilated sequential and randomly using two levels of PEEP: 9 and 15 cmH2 O, and studied with dynamic computed tomography at a fix transversal lung region. Tidal recruitment/derecruitment and hyperinflation were determined as non-aerated tissue and hyperinflated tissue variation between inspiration and expiration, expressed as percentage of total weight. We also assessed the maximal amount of non-aerated and hyperinflated tissue weight. RESULTS PEEP 15 cmH2 O was associated with decrease in non-aerated tissue in all the patients (P < 0.01). However, PEEP 15 cmH2 O did not decrease tidal recruitment/derecruitment compared to PEEP 9 cmH2 O (P = 1). In addition, PEEP 15 cmH2 O markedly increased maximal hyperinflation (P < 0.01) and tidal hyperinflation (P < 0.05). Lung compliance decreased with PEEP 15 cmH2 O (P < 0.001). CONCLUSION In this series of patients with ARDS of mainly pulmonary origin, application of high levels of PEEP did not decrease tidal recruitment/derecruitment, but instead consistently increased tidal and maximal hyperinflation.
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Affiliation(s)
- J. Retamal
- Facultad de Medicina; Departamento de Medicina Intensiva; Pontificia Universidad Católica de Chile; Santiago Chile
- Hedenstierna Laboratory; Surgical Science Department; Uppsala University; Uppsala Sweden
| | - G. Bugedo
- Facultad de Medicina; Departamento de Medicina Intensiva; Pontificia Universidad Católica de Chile; Santiago Chile
| | - A. Larsson
- Hedenstierna Laboratory; Surgical Science Department; Uppsala University; Uppsala Sweden
| | - A. Bruhn
- Facultad de Medicina; Departamento de Medicina Intensiva; Pontificia Universidad Católica de Chile; Santiago Chile
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Tojo K, Nagamine Y, Yazawa T, Mihara T, Baba Y, Ota S, Goto T, Kurahashi K. Atelectasis causes alveolar hypoxia-induced inflammation during uneven mechanical ventilation in rats. Intensive Care Med Exp 2015. [PMID: 26215820 PMCID: PMC4480346 DOI: 10.1186/s40635-015-0056-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Patients with acute respiratory distress syndrome receiving mechanical ventilation show inhomogeneous lung aeration. Atelectasis during uneven mechanical ventilation leads to alveolar hypoxia and could therefore result in lung inflammation and injury. We aimed to elucidate whether and how atelectasis causes alveolar hypoxia-induced inflammation during uneven mechanical ventilation in an open-chest differential-ventilation rat model. METHODS We first investigated inflammatory and histological changes in the bilateral lungs of unilaterally ventilated rats, in which the right lung was atelectatic and the left lung was ventilated with high tidal volume (HTV). In the next series, we investigated the effects of normal tidal volume (NTV) ventilation of the right lungs with 60 % O2 or 100 % N2 during HTV ventilation of the left lungs. Then, proinflammatory cytokine secretions were quantified from murine lung epithelial (MLE15) and murine alveolar macrophage (MH-S) cells cultured under a hypoxic condition (5 % O2) mimicking atelectasis. Further, activities of nuclear factor (NF)-κB and hypoxia-inducible factor (HIF)-1 were assessed in the nonventilated atelectatic lung and MLE15 cells cultured under the hypoxic condition. Finally, effects of NF-κB inhibition and HIF-1α knockdown on the cytokine secretions from MLE15 cells cultured under the hypoxic condition were assessed. RESULTS The nonventilated atelectatic lungs showed inflammatory responses and minimal histological changes comparable to those of the HTV-ventilated lungs. NTV ventilation with 60 % O2 attenuated the increase in chemokine (C-X-C motif) ligand (CXCL)-1 secretion and neutrophil accumulation observed in the atelectatic lungs, but that with 100 % N2 did not. MLE15 cells cultured with tumor necrosis factor (TNF)-α under the hypoxic condition showed increased CXCL-1 secretion. NF-κB and HIF-1α were activated in the nonventilated atelectatic lungs and MLE15 cells cultured under the hypoxic condition. NF-κB inhibition abolished the hypoxia-induced increase in CXCL-1 secretion from MLE15 cells, while HIF-1α knockdown augmented it. CONCLUSIONS Atelectasis causes alveolar hypoxia-induced inflammatory responses including NF-κB-dependent CXCL-1 secretion from lung epithelial cells. HIF-1 activation in lung epithelial cells is an anti-inflammatory response to alveolar hypoxia in atelectatic lungs.
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Affiliation(s)
- Kentaro Tojo
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ku, Yokohama-city, Kanagawa, 236-0004, Japan,
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Andrews PL, Sadowitz B, Kollisch-Singule M, Satalin J, Roy S, Snyder K, Gatto LA, Nieman GF, Habashi NM. Alveolar instability (atelectrauma) is not identified by arterial oxygenation predisposing the development of an occult ventilator-induced lung injury. Intensive Care Med Exp 2015. [PMID: 26215818 PMCID: PMC4480795 DOI: 10.1186/s40635-015-0054-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Improperly set mechanical ventilation (MV) with normal lungs can advance lung injury and increase the incidence of acute respiratory distress syndrome (ARDS). A key mechanism of ventilator-induced lung injury (VILI) is an alteration in alveolar mechanics including alveolar instability or recruitment/derecruitment (R/D). We hypothesize that R/D cannot be identified by PaO2 (masking occult VILI), and if protective ventilation is not applied, ARDS incidence will increase. METHODS Sprague-Dawley rats (n = 8) were anesthetized, surgically instrumented, and placed on MV. A thoracotomy was performed and an in vivo microscope attached to the pleural surface of the lung with baseline dynamic changes in alveolar size during MV recorded. Alveolar instability was induced by intra-tracheal instillation of Tween and alveolar R/D identified as a marked change in alveolar size from inspiration to expiration with increases in positive end-expiratory pressure (PEEP) levels. RESULTS Despite maintaining a clinically acceptable PaO2 (55-80 mmHg), the alveoli remained unstable with significant R/D at low PEEP levels. Although PaO2 consistently increased with an increase in PEEP, R/D did not plateau until PEEP was >9 cmH2O. CONCLUSIONS PaO2 remained clinically acceptable while alveolar instability persisted at all levels of PEEP (especially PEEP <9 cmH2O). Therefore, PaO2 levels cannot be used reliably to guide protective MV strategies or infer that VILI is not occurring. Using PaO2 to set a PEEP level necessary to stabilize the alveoli could underestimate the potential for VILI. These findings highlight the need for more accurate marker(s) of alveolar stability to guide protective MV necessary to prevent VILI.
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Affiliation(s)
- Penny L Andrews
- Department of Critical Care, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA,
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Fernandez-Bustamante A, Hashimoto S, Serpa Neto A, Moine P, Vidal Melo MF, Repine JE. Perioperative lung protective ventilation in obese patients. BMC Anesthesiol 2015; 15:56. [PMID: 25907273 PMCID: PMC4491899 DOI: 10.1186/s12871-015-0032-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 04/02/2015] [Indexed: 12/18/2022] Open
Abstract
The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increasing, and facing these challenges is common in the operating rooms and critical care units worldwide. In this review we summarize the existing literature which supports the following recommendations for the perioperative ventilation in obese patients: (1) the use of protective ventilation with low tidal volumes (approximately 8 mL/kg, calculated based on predicted -not actual- body weight) to avoid volutrauma; (2) a focus on lung recruitment by utilizing PEEP (8–15 cmH2O) in addition to recruitment maneuvers during the intraoperative period, as well as incentivized deep breathing and noninvasive ventilation early in the postoperative period, to avoid atelectasis, hypoxemia and atelectrauma; and (3) a judicious oxygen use (ideally less than 0.8) to avoid hypoxemia but also possible reabsorption atelectasis. Obesity poses an additional challenge for achieving adequate protective ventilation during one-lung ventilation, but different lung isolation techniques have been adequately performed in obese patients by experienced providers. Postoperative efforts should be directed to avoid hypoventilation, atelectasis and hypoxemia. Further studies are needed to better define optimum protective ventilation strategies and analyze their impact on the perioperative outcomes of surgical patients with obesity.
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Affiliation(s)
- Ana Fernandez-Bustamante
- Department of Anesthesiology, University of Colorado SOM, Aurora, CO, USA. .,Department of Anesthesiology and Webb-Waring Center, University of Colorado SOM, Aurora, CO, USA.
| | - Soshi Hashimoto
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA.
| | - Ary Serpa Neto
- Department of Critical Care Medicine, Hospital Israelita Albert Einstein, São Paulo, Brazil. .,Department of Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Pierre Moine
- Department of Anesthesiology, University of Colorado SOM, Aurora, CO, USA.
| | - Marcos F Vidal Melo
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA.
| | - John E Repine
- Department of Anesthesiology and Webb-Waring Center, University of Colorado SOM, Aurora, CO, USA. .,Department of Medicine, University of Colorado SOM, Aurora, CO, USA.
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Jauncey-Cooke J, East CE, Bogossian F. Paediatric lung recruitment: a review of the clinical evidence. Paediatr Respir Rev 2015; 16:127-32. [PMID: 24680638 DOI: 10.1016/j.prrv.2014.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 12/21/2022]
Abstract
Lung recruitment is used as an adjunct to lung protective ventilation strategies. Lung recruitment is a brief, deliberate elevation of transpulmonary pressures beyond what is achieved during tidal ventilation levels. The aim of lung recruitment is to maximise the number of alveoli participating in gas exchange particularly in distal and dependant regions of the lung. This may improve oxygenation and end expiratory levels. Restoration of end expiratory levels and stabilisation of the alveoli may reduce the incidence of ventilator induced lung injury (VILI). Various methods of lung recruitment have been studied in adult and experimental populations. This review aims to establish the evidence for lung recruitment in the pediatric population.
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Affiliation(s)
- Jacqui Jauncey-Cooke
- School of Nursing & Midwifery, The University of Queensland, Australia; Paediatric Critical Care Research Group, PICU, Mater Children's Hospital, Brisbane, Australia.
| | - Chris E East
- School of Nursing and Midwifery/Maternity Services, Monash University/Southern Health, Clayton, Victoria and the School of Nursing & Midwifery, The University of Queensland, Australia.
| | - Fiona Bogossian
- School of Nursing & Midwifery, The University of Queensland, Australia.
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Chacko B, Peter JV, Tharyan P, John G, Jeyaseelan L. Pressure-controlled versus volume-controlled ventilation for acute respiratory failure due to acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). Cochrane Database Syst Rev 2015; 1:CD008807. [PMID: 25586462 PMCID: PMC6457606 DOI: 10.1002/14651858.cd008807.pub2] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) account for one-quarter of cases of acute respiratory failure in intensive care units (ICUs). A third to half of patients will die in the ICU, in hospital or during follow-up. Mechanical ventilation of people with ALI/ARDS allows time for the lungs to heal, but ventilation is invasive and can result in lung injury. It is uncertain whether ventilator-related injury would be reduced if pressure delivered by the ventilator with each breath is controlled, or whether the volume of air delivered by each breath is limited. OBJECTIVES To compare pressure-controlled ventilation (PCV) versus volume-controlled ventilation (VCV) in adults with ALI/ARDS to determine whether PCV reduces in-hospital mortality and morbidity in intubated and ventilated adults. SEARCH METHODS In October 2014, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Isssue 9), MEDLINE (1950 to 1 October 2014), EMBASE (1980 to 1 October 2014), the Latin American Caribbean Health Sciences Literature (LILACS) (1994 to 1 October 2014) and Science Citation Index-Expanded (SCI-EXPANDED) at the Institute for Scientific Information (ISI) Web of Science (1990 to 1 October 2014), as well as regional databases, clinical trials registries, conference proceedings and reference lists. SELECTION CRITERIA Randomized controlled trials (RCTs) and quasi-RCTs (irrespective of language or publication status) of adults with a diagnosis of acute respiratory failure or acute on chronic respiratory failure and fulfilling the criteria for ALI/ARDS as defined by the American-European Consensus Conference who were admitted to an ICU for invasive mechanical ventilation, comparing pressure-controlled or pressure-controlled inverse-ratio ventilation, or an equivalent pressure-controlled mode (PCV), versus volume-controlled ventilation, or an equivalent volume-controlled mode (VCV). DATA COLLECTION AND ANALYSIS Two review authors independently screened and selected trials, assessed risk of bias and extracted data. We sought clarification from trial authors when needed. We pooled risk ratios (RRs) for dichotomous data and mean differences (MDs) for continuous data with their 95% confidence intervals (CIs) using a random-effects model. We assessed overall evidence quality using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. MAIN RESULTS We included three RCTs that randomly assigned a total of 1089 participants recruited from 43 ICUs in Australia, Canada, Saudi Arabia, Spain and the USA. Risk of bias of the included studies was low. Only data for mortality and barotrauma could be combined in the meta-analysis. We downgraded the quality of evidence for the three mortality outcomes on the basis of serious imprecision around the effect estimates. For mortality in hospital, the RR with PCV compared with VCV was 0.83 (95% CI 0.67 to 1.02; three trials, 1089 participants; moderate-quality evidence), and for mortality in the ICU, the RR with PCV compared with VCV was 0.84 (95% CI 0.71 to 0.99; two trials, 1062 participants; moderate-quality evidence). One study provided no evidence of clear benefit with the ventilatory mode for mortality at 28 days (RR 0.88, 95% CI 0.73 to 1.06; 983 participants; moderate-quality evidence). The difference in effect on barotrauma between PCV and VCV was uncertain as the result of imprecision and different co-interventions used in the studies (RR 1.24, 95% CI 0.87 to 1.77; two trials, 1062 participants; low-quality evidence). Data from one trial with 983 participants for the mean duration of ventilation, and from another trial with 78 participants for the mean number of extrapulmonary organ failures that developed with PCV or VCV, were skewed. None of the trials reported on infection during ventilation or quality of life after discharge. AUTHORS' CONCLUSIONS Currently available data from RCTs are insufficient to confirm or refute whether pressure-controlled or volume-controlled ventilation offers any advantage for people with acute respiratory failure due to acute lung injury or acute respiratory distress syndrome. More studies including a larger number of people given PCV and VCV may provide reliable evidence on which more firm conclusions can be based.
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Affiliation(s)
- Binila Chacko
- Christian Medical College & HospitalMedical Intensive Care UnitVelloreIndia
| | - John V Peter
- Christian Medical College & HospitalMedical Intensive Care UnitVelloreIndia
| | - Prathap Tharyan
- Christian Medical CollegeCochrane South Asia, Prof. BV Moses Centre for Evidence‐Informed Healthcare and Health PolicyCarman Block II FloorCMC Campus, BagayamVelloreTamil NaduIndia632002
| | - George John
- Christian Medical College & HospitalMedical Intensive Care UnitVelloreIndia
| | - Lakshmanan Jeyaseelan
- Christian Medical CollegeDepartment of BiostatisticsBagayamVelloreTamil NaduIndia632002
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Sutherasan Y, D'Antini D, Pelosi P. Advances in ventilator-associated lung injury: prevention is the target. Expert Rev Respir Med 2014; 8:233-48. [PMID: 24601663 DOI: 10.1586/17476348.2014.890519] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mechanical ventilation (MV) is the main supportive treatment in respiratory failure due to different etiologies. However, MV might aggravate ventilator-associated lung injury (VALI). Four main mechanisms leading to VALI are: 1) increased stress and strain, induced by high tidal volume (VT); 2) increased shear stress, i.e. opening and closing, of previously atelectatic alveolar units; 3) distribution of perfusion and 4) biotrauma. In severe acute respiratory distress syndrome patients, low VT, higher levels of positive end expiratory pressure, long duration prone position and neuromuscular blockade within the first 48 hours are associated to a better outcome. VALI can also occur by using high VT in previously non injured lungs. We believe that prevention is the target to minimize injurious effects of MV. This review aims to describe pathophysiology of VALI, the possible prevention and treatment as well as monitoring MV to minimize VALI.
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Affiliation(s)
- Yuda Sutherasan
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, IRCCS San Martino - IST, Genoa, Italy
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Kollisch-Singule M, Emr B, Smith B, Ruiz C, Roy S, Meng Q, Jain S, Satalin J, Snyder K, Ghosh A, Marx WH, Andrews P, Habashi N, Nieman GF, Gatto LA. Airway pressure release ventilation reduces conducting airway micro-strain in lung injury. J Am Coll Surg 2014; 219:968-76. [PMID: 25440027 DOI: 10.1016/j.jamcollsurg.2014.09.011] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/25/2014] [Accepted: 08/01/2014] [Indexed: 12/18/2022]
Abstract
BACKGROUND Improper mechanical ventilation can exacerbate acute lung damage, causing a secondary ventilator-induced lung injury (VILI). We hypothesized that VILI can be reduced by modifying specific components of the ventilation waveform (mechanical breath), and we studied the impact of airway pressure release ventilation (APRV) and controlled mandatory ventilation (CMV) on the lung micro-anatomy (alveoli and conducting airways). The distribution of gas during inspiration and expiration and the strain generated during mechanical ventilation in the micro-anatomy (micro-strain) were calculated. STUDY DESIGN Rats were anesthetized, surgically prepared, and randomized into 1 uninjured control group (n = 2) and 4 groups with lung injury: APRV 75% (n = 2), time at expiration (TLow) set to terminate appropriately at 75% of peak expiratory flow rate (PEFR); APRV 10% (n = 2), TLow set to terminate inappropriately at 10% of PEFR; CMV with PEEP 5 cm H2O (PEEP 5; n = 2); or PEEP 16 cm H2O (PEEP 16; n = 2). Lung injury was induced in the experimental groups by Tween lavage and ventilated with their respective settings. Lungs were fixed at peak inspiration and end expiration for standard histology. Conducting airway and alveolar air space areas were quantified and conducting airway micro-strain was calculated. RESULTS All lung injury groups redistributed inspired gas away from alveoli into the conducting airways. The APRV 75% minimized gas redistribution and micro-strain in the conducting airways and provided the alveolar air space occupancy most similar to control at both inspiration and expiration. CONCLUSIONS In an injured lung, APRV 75% maintained micro-anatomic gas distribution similar to that of the normal lung. The lung protection demonstrated in previous studies using APRV 75% may be due to a more homogeneous distribution of gas at the micro-anatomic level as well as a reduction in conducting airway micro-strain.
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Affiliation(s)
| | - Bryanna Emr
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Bradford Smith
- Department of Medicine, University of Vermont, Burlington, VT
| | - Cynthia Ruiz
- Department of Biological Sciences, SUNY Cortland, Cortland, NY
| | - Shreyas Roy
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Qinghe Meng
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Sumeet Jain
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Joshua Satalin
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY.
| | - Kathy Snyder
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Auyon Ghosh
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - William H Marx
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Penny Andrews
- R Adams Cowley Shock Trauma Center, Trauma Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD
| | - Nader Habashi
- R Adams Cowley Shock Trauma Center, Trauma Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD
| | - Gary F Nieman
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Louis A Gatto
- Department of General Surgery, SUNY Upstate Medical University, Syracuse, NY; Department of Biological Sciences, SUNY Cortland, Cortland, NY
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Effects of high-frequency oscillatory ventilation and conventional mechanical ventilation on oxygen metabolism and tissue perfusion in sheep models of acute respiratory distress syndrome. Chin Med J (Engl) 2014. [DOI: 10.1097/00029330-201409200-00010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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A patient-specific airway branching model for mechanically ventilated patients. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2014; 2014:645732. [PMID: 25214888 PMCID: PMC4158163 DOI: 10.1155/2014/645732] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND Respiratory mechanics models have the potential to guide mechanical ventilation. Airway branching models (ABMs) were developed from classical fluid mechanics models but do not provide accurate models of in vivo behaviour. Hence, the ABM was improved to include patient-specific parameters and better model observed behaviour (ABMps). METHODS The airway pressure drop of the ABMps was compared with the well-accepted dynostatic algorithm (DSA) in patients diagnosed with acute respiratory distress syndrome (ARDS). A scaling factor (α) was used to equate the area under the pressure curve (AUC) from the ABMps to the AUC of the DSA and was linked to patient state. RESULTS The ABMps recorded a median α value of 0.58 (IQR: 0.54-0.63; range: 0.45-0.66) for these ARDS patients. Significantly lower α values were found for individuals with chronic obstructive pulmonary disease (P < 0.001). CONCLUSION The ABMps model allows the estimation of airway pressure drop at each bronchial generation with patient-specific physiological measurements and can be generated from data measured at the bedside. The distribution of patient-specific α values indicates that the overall ABM can be readily improved to better match observed data and capture patient condition.
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Young RW. Prevention of lung injury in cardiac surgery: a review. THE JOURNAL OF EXTRA-CORPOREAL TECHNOLOGY 2014; 46:130-41. [PMID: 25208430 PMCID: PMC4566423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/07/2014] [Indexed: 06/03/2023]
Abstract
Inflammatory lung injury is an inevitable consequence of cardiac surgery with cardiopulmonary bypass. The lungs are particularly susceptible to the effects of the systemic inflammatory response to cardiopulmonary bypass. This insult is further exacerbated by a pulmonary ischemia-reperfusion injury after termination of bypass. Older patients and those with pre-existing lung disease will clearly be less tolerant of any lung injury and more likely to develop respiratory failure in the postoperative period. A requirement for prolonged ventilation has implications for morbidity, mortality, and cost of treatment. This review contains a summary of recent interventions and changes of practice that may reduce inflammatory lung injury after cardiac surgery. The review also focuses on a number of general aspects of perioperative management, which may exacerbate such injury, if performed poorly.
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Ning J. Diagnosis and treatment of children with severe influenza A from the 2009/2010 pandemic in Tianjin, China. Trop Doct 2014; 44:69-70. [PMID: 24414043 DOI: 10.1177/0049475513517230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The clinical characteristics and treatments of severe influenza A (H1N1) in infected children were discussed and analysed. We found that such severe cases predominantly manifested respiratory symptoms; symptoms affecting the nervous system are also rare but dangerous. The clinical data of eight children with severe influenza A (H1N1) were analysed retrospectively. These children generally manifested fever and flu-like symptoms, short-term aggravation with dyspnoea. One case exhibited neurological symptoms. After continuous positive airway pressure and immunological regulation were administered, the clinical symptoms gradually improved. Patients with severe influenza A (H1N1) manifested respiratory tract symptoms. Those exhibiting neurological symptoms were seriously affected. Physical signs were regularly monitored and laboratory examination was conducted in order to determine the causes of severe illness. The treatments were adjusted accordingly.
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Affiliation(s)
- Jing Ning
- Associate Chief Physician, Tianjin Children's Hospital, Tianjin, China
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40
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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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41
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Turner DA, Ofori-Amanfo G, Williford WL, Cheifetz IM. Lung protective ventilation: a summary of the current evidence from the 2012 American Association for Respiratory Care International Congress. Expert Rev Respir Med 2014; 7:209-12. [DOI: 10.1586/ers.13.28] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Abstract
Mechanical ventilation (MV) is, by definition, the application of external forces to the lungs. Depending on their magnitude, these forces can cause a continuum of pathophysiological alterations ranging from the stimulation of inflammation to the disruption of cell-cell contacts and cell membranes. These side effects of MV are particularly relevant for patients with inhomogeneously injured lungs such as in acute lung injury (ALI). These patients require supraphysiological ventilation pressures to guarantee even the most modest gas exchange. In this situation, ventilation causes additional strain by overdistension of the yet non-injured region, and additional stress that forms because of the interdependence between intact and atelectatic areas. Cells are equipped with elaborate mechanotransduction machineries that respond to strain and stress by the activation of inflammation and repair mechanisms. Inflammation is the fundamental response of the host to external assaults, be they of mechanical or of microbial origin and can, if excessive, injure the parenchymal tissue leading to ALI. Here, we will discuss the forces generated by MV and how they may injure the lungs mechanically and through inflammation. We will give an overview of the mechanotransduction and how it leads to inflammation and review studies demonstrating that ventilator-induced lung injury can be prevented by blocking pathways of mechanotransduction or inflammation.
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Affiliation(s)
- Ulrike Uhlig
- Department of Pharmacology & Toxicology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Cruces P, Erranz B, Donoso A, Carvajal C, Salomón T, Torres MF, Díaz F. Mild hypothermia increases pulmonary anti-inflammatory response during protective mechanical ventilation in a piglet model of acute lung injury. Paediatr Anaesth 2013; 23:1069-77. [PMID: 23731357 DOI: 10.1111/pan.12209] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/08/2013] [Indexed: 12/15/2022]
Abstract
BACKGROUND The effects of mild hypothermia (HT) on acute lung injury (ALI) are unknown in species with metabolic rate similar to that of humans, receiving protective mechanical ventilation (MV). We hypothesized that mild hypothermia would attenuate pulmonary and systemic inflammatory responses in piglets with ALI managed with a protective MV. METHODS Acute lung injury (ALI) was induced with surfactant deactivation in 38 piglets. The animals were then ventilated with low tidal volume, moderate positive end-expiratory pressure (PEEP), and permissive hypercapnia throughout the experiment. Subjects were randomized to HT (33.5°C) or normothermia (37°C) groups over 4 h. Plasma and tissue cytokines, tissue apoptosis, lung mechanics, pulmonary vascular permeability, hemodynamic, and coagulation were evaluated. RESULTS Lung interleukin-10 concentrations were higher in subjects that underwent HT after ALI induction than in those that maintained normothermia. No difference was found in other systemic and tissue cytokines. HT did not induce lung or kidney tissue apoptosis or influence lung mechanics or markers of pulmonary vascular permeability. Heart rate, cardiac output, oxygen uptake, and delivery were significantly lower in subjects that underwent HT, but no difference in arterial lactate, central venous oxygen saturation, and coagulation test was observed. CONCLUSIONS Mild hypothermia induced a local anti-inflammatory response in the lungs, without affecting lung function or coagulation, in this piglet model of ALI. The HT group had lower cardiac output without signs of global dysoxia, suggesting an adaptation to the decrease in oxygen uptake and delivery. Studies are needed to determine the therapeutic role of HT in ALI.
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Affiliation(s)
- Pablo Cruces
- Área de Cuidados Críticos, Hospital Padre Hurtado, Santiago, Chile; Centro de Investigación de Medicina Veterinaria, Escuela de Medicina Veterinaria, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello, Santiago, Chile
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Effect of PEEP and tidal volume on ventilation distribution and end-expiratory lung volume: a prospective experimental animal and pilot clinical study. PLoS One 2013; 8:e72675. [PMID: 23991138 PMCID: PMC3750001 DOI: 10.1371/journal.pone.0072675] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 07/18/2013] [Indexed: 11/19/2022] Open
Abstract
Introduction Lung-protective ventilation aims at using low tidal volumes (VT) at optimum positive end-expiratory pressures (PEEP). Optimum PEEP should recruit atelectatic lung regions and avoid tidal recruitment and end-inspiratory overinflation. We examined the effect of VT and PEEP on ventilation distribution, regional respiratory system compliance (CRS), and end-expiratory lung volume (EELV) in an animal model of acute lung injury (ALI) and patients with ARDS by using electrical impedance tomography (EIT) with the aim to assess tidal recruitment and overinflation. Methods EIT examinations were performed in 10 anaesthetized pigs with normal lungs ventilated at 5 and 10 ml/kg body weight VT and 5 cmH2O PEEP. After ALI induction, 10 ml/kg VT and 10 cmH2O PEEP were applied. Afterwards, PEEP was set according to the pressure-volume curve. Animals were randomized to either low or high VT ventilation changed after 30 minutes in a crossover design. Ventilation distribution, regional CRS and changes in EELV were analyzed. The same measures were determined in five ARDS patients examined during low and high VT ventilation (6 and 10 (8) ml/kg) at three PEEP levels. Results In healthy animals, high compared to low VT increased CRS and ventilation in dependent lung regions implying tidal recruitment. ALI reduced CRS and EELV in all regions without changing ventilation distribution. Pressure-volume curve-derived PEEP of 21±4 cmH2O (mean±SD) resulted in comparable increase in CRS in dependent and decrease in non-dependent regions at both VT. This implied that tidal recruitment was avoided but end-inspiratory overinflation was present irrespective of VT. In patients, regional CRS differences between low and high VT revealed high degree of tidal recruitment and low overinflation at 3±1 cmH2O PEEP. Tidal recruitment decreased at 10±1 cmH2O and was further reduced at 15±2 cmH2O PEEP. Conclusions Tidal recruitment and end-inspiratory overinflation can be assessed by EIT-based analysis of regional CRS.
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Cyclic recruitment of atelectasis – Are there implications for our clinical practice? TRENDS IN ANAESTHESIA AND CRITICAL CARE 2013. [DOI: 10.1016/j.tacc.2013.02.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Higher Frequency Ventilation Attenuates Lung Injury during High-frequency Oscillatory Ventilation in Sheep Models of Acute Respiratory Distress Syndrome. Anesthesiology 2013; 119:398-411. [DOI: 10.1097/aln.0b013e31829419a6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Abstract
Background:
High-frequency oscillatory ventilation (HFOV) at higher frequencies minimizes the tidal volume. However, whether increased frequencies during HFOV can reduce ventilator-induced lung injury remains unknown.
Methods:
After the induction of acute respiratory distress syndrome in the model by repeated lavages, 24 adult sheep were randomly divided into four groups (n = 6): three HFOV groups (3, 6, and 9 Hz) and one conventional mechanical ventilation (CMV) group. Standard lung recruitments were performed in all groups until optimal alveolar recruitment was reached. After lung recruitment, the optimal mean airway pressure or positive end-expiratory pressure was determined with decremental pressure titration, 2 cm H2O every 10 min. Animals were ventilated for 4 h.
Results:
After lung recruitment, sustained improvements in gas exchange and compliance were observed in all groups. Compared with the HFOV-3 Hz and CMV groups, the transpulmonary pressure and tidal volumes were statistically significantly lower in the HFOV-9 Hz group. The lung injury scores and wet/dry weight ratios were significantly reduced in the HFOV-9 Hz group compared with the HFOV-3 Hz and CMV groups. Expression of interleukin-1β and interleukin-6 in the lung tissue, decreased significantly in the HFOV-9 Hz group compared with the HFOV-3 Hz and CMV groups. Malondialdehyde expression and myeloperoxidase activity in lung tissues in the HFOV-9 Hz group decreased significantly, compared with the HFOV-3 Hz and CMV groups.
Conclusion:
The use of HFOV at 9 Hz minimizes lung stress and tidal volumes, resulting in less lung injury and reduced levels of inflammatory mediators compared with the HFOV-3 Hz and CMV conditions.
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Early airway pressure release ventilation prevents ARDS-a novel preventive approach to lung injury. Shock 2013; 39:28-38. [PMID: 23247119 DOI: 10.1097/shk.0b013e31827b47bb] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Acute respiratory distress syndrome (ARDS) afflicts 200,000 patients annually with a mortality rate of 30% to 60% despite wide use of low tidal volume (LTV) ventilation, the present standard of care. High-permeability alveolar edema and instability occur early in the development of ARDS, before clinical signs of lung injury, and represent potential targets for therapy. We hypothesize that early application of a protective ventilation strategy (airway pressure release ventilation [APRV]) will stabilize alveoli and reduce alveolar edema, preventing the development of ARDS. Yorkshire pigs (30-40 kg) were anesthetized and subjected to two-hit injury: (a) intestinal ischemia-reperfusion, (b) peritoneal sepsis, or sham surgery. Following surgery, pigs were randomized into APRV (n = 4), according to current published guidelines for APRV; LTV ventilation (n = 3), using the current published ARDS Network guidelines (6 mL/kg); or sham (n = 5). The clinical care of all pigs was administered per the Surviving Sepsis Campaign guidelines. Animals were killed, and necropsy performed at 48 h. Arterial blood gases were measured to assess for the development of clinical lung injury. Lung tissue epithelial cadherin (E-cadherin) was measured to assess alveolar permeability. Bronchoalveolar lavage fluid (BALF) surfactant protein A was measured to assess alveolar stability. Lung edema content and histopathology were analyzed at 48 h. Airway pressure release ventilation pigs did not develop ARDS. In contrast, pigs in the LTV ventilation met ARDS criteria (PaO2/FIO2 ratio) (APRV: baseline = 471 ± 16; 48 h = 392 ± 8; vs. LTV ventilation: baseline = 551 ± 28; 48 h = 138 ± 88; P < 0.001). Airway pressure release ventilation preserved alveolar epithelial integrity demonstrated by higher levels of E-cadherin in lung tissue as compared with LTV ventilation (P < 0.05). Surfactant protein A levels were higher in BALF from the APRV group, suggesting APRV preserved alveolar stability. Quantitative histologic scoring showed improvements in all stigmata of ARDS in the APRV group versus the LTV ventilation (P < 0.05). Airway pressure release ventilation had significantly lower lung edema (wet-dry weight) than LTV ventilation (P < 0.05). Protective ventilation with APRV immediately following injury prevents development of ARDS. Reduction in lung edema, preservation of lung E-cadherin, and surfactant protein A abundance in BALF suggest that APRV attenuates lung permeability, edema, and surfactant degradation. Protective ventilation could change the clinical paradigm from supportive care for ARDS with LTV ventilation to preventing development of ARDS with APRV.
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Endoscopic Imaging to Assess Alveolar Mechanics During Quasi-static and Dynamic Ventilatory Conditions in Rats With Noninjured and Injured Lungs*. Crit Care Med 2013; 41:1286-95. [DOI: 10.1097/ccm.0b013e31827712fa] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Miedema M, van der Burg PS, Beuger S, de Jongh FH, Frerichs I, van Kaam AH. Effect of nasal continuous and biphasic positive airway pressure on lung volume in preterm infants. J Pediatr 2013; 162:691-7. [PMID: 23102792 DOI: 10.1016/j.jpeds.2012.09.027] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 07/19/2012] [Accepted: 09/17/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE To monitor regional changes in end-expiratory lung volume (EELV), tidal volumes, and their ventilation distribution during different levels of nasal continuous positive airway pressure (nCPAP) and nasal biphasic positive airway pressure (BiPAP) in stable preterm infants. STUDY DESIGN By using electrical impedance tomography and respiratory inductive plethysmography, we measured changes in EELV and tidal volumes in 22 preterm infants (gestational age 29.7 ± 1.5 weeks) during 3 nCPAP levels (2, 4, and 6 cmH2O) and unsynchronized BiPAP (nCPAP = 6 cmH2O; pressure amplitude = 3 cmH2O; frequency = 50/min; inspiration time = 0.5 seconds) at 10-minute intervals. We assessed the distribution of these volumes in ventral and dorsal chest regions by using electrical impedance tomography. RESULTS EELV increased with increasing nCPAP with no difference between the ventral and dorsal lung regions. Tidal volume also increased, and a decrease in phase angle and respiratory rate was noted by respiratory induction plethysmography. At the regional level, electrical impedance tomography data showed a more dorsally oriented ventilation distribution. BiPAP resulted in a small increase in EELV but without changes in tidal volume or its regional distribution. CONCLUSION Increasing nCPAP in the range of 2 to 6 cmH2O results in a homogeneous increase in EELV and an increase in tidal volume in preterm infants with a more physiologic ventilation distribution. Unsynchronized BiPAP does not improve tidal volume compared with nCPAP.
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Affiliation(s)
- Martijn Miedema
- Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
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Retamal J, Libuy J, Jiménez M, Delgado M, Besa C, Bugedo G, Bruhn A. Preliminary study of ventilation with 4 ml/kg tidal volume in acute respiratory distress syndrome: feasibility and effects on cyclic recruitment - derecruitment and hyperinflation. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:R16. [PMID: 23351488 PMCID: PMC4056568 DOI: 10.1186/cc12487] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 01/14/2013] [Indexed: 02/07/2023]
Abstract
Introduction Cyclic recruitment-derecruitment and overdistension contribute to ventilator-induced lung injury. Tidal volume (Vt) may influence both, cyclic recruitment-derecruitment and overdistension. The goal of this study was to determine if decreasing Vt from 6 to 4 ml/kg reduces cyclic recruitment-derecruitment and hyperinflation, and if it is possible to avoid severe hypercapnia. Methods Patients with pulmonary acute respiratory distress syndrome (ARDS) were included in a crossover study with two Vt levels: 6 and 4 ml/kg. The protocol had two parts: one bedside and other at the CT room. To avoid severe hypercapnia in the 4 ml/kg arm, we replaced the heat and moisture exchange filter by a heated humidifier, and respiratory rate was increased to keep minute ventilation constant. Data on lung mechanics and gas exchange were taken at baseline and after 30 minutes at each Vt (bedside). Thereafter, a dynamic CT (4 images/sec for 8 sec) was taken at each Vt at a fixed transverse region between the middle and lower third of the lungs. Afterward, CT images were analyzed and cyclic recruitment-derecruitment was determined as non-aerated tissue variation between inspiration and expiration, and hyperinflation as maximal hyperinflated tissue at end-inspiration, expressed as % of lung tissue weight. Results We analyzed 10 patients. Decreasing Vt from 6 to 4 ml/kg consistently decreased cyclic recruitment-derecruitment from 3.6 (2.5 to 5.7) % to 2.9 (0.9 to 4.7) % (P <0.01) and end-inspiratory hyperinflation from 0.7 (0.3 to 2.2) to 0.6 (0.2 to 1.7) % (P = 0.01). No patient developed severe respiratory acidosis or severe hypercapnia when decreasing Vt to 4 ml/kg (pH 7.29 (7.21 to 7.46); PaCO2 48 (26 to 51) mmHg). Conclusions Decreasing Vt from 6 to 4 ml/kg reduces cyclic recruitment-derecruitment and hyperinflation. Severe respiratory acidosis may be effectively prevented by decreasing instrumental dead space and by increasing respiratory rate.
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