Association Between Use of Lung-Protective Ventilation With Lower Tidal Volumes and Clinical Outcomes Among Patients Without Acute Respiratory Distress Syndrome A Meta-analysis

Department of Critical Care Medicine, ABC Medical School, Santo André, São Paulo, Brazil.
JAMA The Journal of the American Medical Association (Impact Factor: 35.29). 10/2012; 308(16):1651-9. DOI: 10.1001/jama.2012.13730
Source: PubMed

ABSTRACT Lung-protective mechanical ventilation with the use of lower tidal volumes has been found to improve outcomes of patients with acute respiratory distress syndrome (ARDS). It has been suggested that use of lower tidal volumes also benefits patients who do not have ARDS.
To determine whether use of lower tidal volumes is associated with improved outcomes of patients receiving ventilation who do not have ARDS.
MEDLINE, CINAHL, Web of Science, and Cochrane Central Register of Controlled Trials up to August 2012.
Eligible studies evaluated use of lower vs higher tidal volumes in patients without ARDS at onset of mechanical ventilation and reported lung injury development, overall mortality, pulmonary infection, atelectasis, and biochemical alterations.
Three reviewers extracted data on study characteristics, methods, and outcomes. Disagreement was resolved by consensus.
Twenty articles (2822 participants) were included. Meta-analysis using a fixed-effects model showed a decrease in lung injury development (risk ratio [RR], 0.33; 95% CI, 0.23 to 0.47; I2, 0%; number needed to treat [NNT], 11), and mortality (RR, 0.64; 95% CI, 0.46 to 0.89; I2, 0%; NNT, 23) in patients receiving ventilation with lower tidal volumes. The results of lung injury development were similar when stratified by the type of study (randomized vs nonrandomized) and were significant only in randomized trials for pulmonary infection and only in nonrandomized trials for mortality. Meta-analysis using a random-effects model showed, in protective ventilation groups, a lower incidence of pulmonary infection (RR, 0.45; 95% CI, 0.22 to 0.92; I2, 32%; NNT, 26), lower mean (SD) hospital length of stay (6.91 [2.36] vs 8.87 [2.93] days, respectively; standardized mean difference [SMD], 0.51; 95% CI, 0.20 to 0.82; I2, 75%), higher mean (SD) PaCO2 levels (41.05 [3.79] vs 37.90 [4.19] mm Hg, respectively; SMD, -0.51; 95% CI, -0.70 to -0.32; I2, 54%), and lower mean (SD) pH values (7.37 [0.03] vs 7.40 [0.04], respectively; SMD, 1.16; 95% CI, 0.31 to 2.02; I2, 96%) but similar mean (SD) ratios of PaO2 to fraction of inspired oxygen (304.40 [65.7] vs 312.97 [68.13], respectively; SMD, 0.11; 95% CI, -0.06 to 0.27; I2, 60%). Tidal volume gradients between the 2 groups did not influence significantly the final results.
Among patients without ARDS, protective ventilation with lower tidal volumes was associated with better clinical outcomes. Some of the limitations of the meta-analysis were the mixed setting of mechanical ventilation (intensive care unit or operating room) and the duration of mechanical ventilation.

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    • "All tracheal intubations should have their position confirmed with waveform capnography in addition to auscultation [2,34,35]. Protective lung ventilation including tidal volumes of 6-8 ml/kg, plateau pressures less than 30cmH20, optimal PEEP and titrated FiO2 should be initiated as soon as possible in all critically ill patients [59,60]. In patients with a neurological insult, neuro-protective ventilation with tight PaCO2 control (4.5-5kPa) and a PaO2 greater than 10kPa may be appropriate [61]. "
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    ABSTRACT: IntroductionRapid sequence induction (RSI) of critically ill patients outside of theatres is associated with a higher risk of hypoxia, cardiovascular collapse and death. In the prehospital and military environments, there is an increasing awareness of the benefits of standardised practice and checklists.Methods We conducted a non-systematic review of literature pertaining to key components of RSI preparation and management. A standard operating procedure (SOP) for in-hospital RSI was developed based on this and experience from large teaching hospital anaesthesia and critical care departments.ResultsThe SOP consists of a RSI equipment set-up sheet, pre-RSI checklist and failed airway algorithm. The SOP should improve RSI preparation, crew resource management and first pass intubation success while minimising adverse events.Conclusion Based on the presented literature, we believe the evidence is sufficient to recommend adoption of the core components in the suggested SOP. This standardised approach to RSI in the critically ill may reduce the current high incidence of adverse events and hopefully improve patient outcomes.
    Scandinavian Journal of Trauma Resuscitation and Emergency Medicine 09/2014; 22(1):41. DOI:10.1186/s13049-014-0041-7 · 2.03 Impact Factor
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    • "Recent results suggest that intraoperative ventilation also is a risk factor for ventilator-induced lung injury [7,8]. Thus, intraoperative EIT monitoring of tidal volume distribution could be a tool to establish lung-protective ventilation, especially in patients at increased risk, such as for patients undergoing major open upper abdominal surgery. "
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    ABSTRACT: Background Electrical impedance tomography (EIT) of the lungs facilitates visualization of ventilation distribution during mechanical ventilation. Its intraoperative use could provide the basis for individual optimization of ventilator settings, especially in patients at risk for ventilation-perfusion mismatch and impaired gas exchange, such as patients undergoing major open upper abdominal surgery. EIT throughout major open upper abdominal surgery could encounter difficulties in belt positioning and signal quality. Thus, we conducted a pilot-study and tested whether EIT is feasible in patients undergoing major open upper abdominal surgery. Methods Following institutional review board’s approval and written informed consent, we included patients scheduled for major open upper abdominal surgery of at least 3 hours duration. EIT measurements were conducted prior to intubation, at the time of skin incision, then hourly during surgery until shortly prior to extubation and after extubation. Number of successful intraoperative EIT measurements and reasons for failures were documented. From the valid measurements, a functional EIT image of changes in tidal impedance was generated for every time point. Regions of interest were defined as horizontal halves of the picture. Monitoring of ventilation distribution was assessed using the center of ventilation index, and also using the total and dorsal ventilated lung area. All parameter values prior to and post intubation as well as extubation were compared. A p < 0.05 was considered statistically significant. Results A total of 120 intraoperative EIT measurements during major abdominal surgery lasting 4-13 hours were planned in 14 patients. The electrode belt was attached between the 2nd and 4th intercostal space. Consecutive valid measurements could be acquired in 13 patients (93%). 111 intraoperative measurements could be retrieved as planned (93%). Main obstacle was the contact of skin electrodes. Despite the high belt position, distribution of tidal volume showed a significant shift of ventilation towards ventral lung regions after intubation. This was reversed after weaning from mechanical ventilation. Conclusions Despite a high belt position, monitoring of ventilation distribution is feasible in patients undergoing major open upper abdominal surgery lasting from 4 to 13 hours. Therefore, further interventional trials in order to optimize ventilatory management should be initiated.
    BMC Anesthesiology 07/2014; 14(1):51. DOI:10.1186/1471-2253-14-51 · 1.38 Impact Factor
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    • "Chaque anné e en France, plusieurs millions de patients sont ventilé s mé caniquement lors d'interventions ré alisé es sous anesthé sie gé né rale [1]. La ventilation mé canique est associé e a ` de multiples complications postopé ratoires, notamment respiratoires [2]. En effet, la ventilation mé canique provoque des lé sions alvé olaires mé caniques (até lectasie ou surdistension alvé olaire) et biologiques (activation locale de l'inflammation) [3]. "
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    ABSTRACT: Mechanical ventilation can initiate ventilator-associated lung injury and postoperative pulmonary complications. The aim of this study was to evaluate (1) how mechanical ventilation was comprehended by anaesthetists (physician and nurses) and (2) the need for educational programs.
    Annales francaises d'anesthesie et de reanimation 06/2014; · 0.84 Impact Factor
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