PURPOSE:It has been debated as to what level of positive end-expiratory pressure (PEEP) should be applied in acute respiratory distress syndrome (ARDS) and acute lung injury (ALI). The purpose of this study was to evaluate the effect and safety of higher PEEP levels in ARDS/ALI.
METHODS:A systematic literature search was conducted to identify all randomized controlled trials comparing high PEEP levels with low levels and reporting mortality data. A Risk difference (RD) or weighted mean difference (WMD) with a 95% confidence interval (CI) was calculated for each outcome and a Z-test was performed to examine the overall effect. A random effects model was used if significant heterogeneity was found and a fixed effects model was used if not.
RESULTS:Three trials including a total of 2299 patients were analyzed. Mean PEEP values on days 1 through 7 were 8.1 cmH2O in the lower PEEP group and 12.8 cm H2O in the higher PEEP group. There was a trend toward decreased 28-day mortality with the high PEEP levels (RD (fixed) = -4%; 95% CI: -8 to 1; P = 0.10) compared with the low levels. Higher PEEP levels marginally reduced hospital mortality (RD (fixed) = -4%; 95% CI: -7 to 0; P = 0.08). There was no statistically significant difference in ICU (WMD (fixed) = 0.04 days; 95% CI: -1.03 to 1.10; P = 0.94), ventilator (WMD (random) = 1.03 days; 95% CI: -1.44 to 3.51; P = 0.41), or organ failure free days (WMD (random) = 2.01days; 95% CI: -1.91 to 5.93; P = 0.32) between the two groups. The incidence of barotrauma was also similar in the two groups. (RD (fixed) = 1%; 95% CI: -1 to 4; P = 0.25).
CONCLUSION:High PEEP levels are safe and produce a small, but potentially important, reduction in hospital mortality in patients with ARDS/ALI.
CLINICAL IMPLICATIONS:The use of high PEEP as employed in the clinical studies is encouraged to save additional lives in ARDS/ALI.
DISCLOSURE:Danish Thameem, No Financial Disclosure Information; No Product/Research Disclosure Information