Higher PEEP versus Lower PEEP Strategies for Patients in ICU without Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

Abstract Purpose To evaluate the effects of high and low levels of PEEP on ICU patients without ARDS. Methods We searched public databases (including PubMed, EMBASE, Cochrane Library and Clinicaltrial.gov ). The Cochrane Risk of Bias Assessment tool was used to evaluate the quality of the included studies. Results We included 2307 patients from 24 trials. Although no significant difference was found between high and low PEEP applications in in-hospital mortality (risk ratio[RR] 0.98, 95% confidence interval[CI] [0.81, 1.19], P = 0.87), high PEEP indeed decreased the incidence of ARDS, hypoxemia, and increased the level of PaO2/FIO2. In addition, although the overall results did not reveal any advantages of high PEEP in terms of secondary outcomes regarding 28-day mortality, the duration of ventilation, atelectasis, pulmonary barotrauma, hypotension, and so forth, the subgroup analysis concerning the level of low PEEP (ZEEP or not) and patient type (postoperative or medical ones) yielded different results. The TSA results suggested that more RCTs are needed. Conclusions Although ventilation with high PEEP in ICU patients without ARDS may not reduce in-hospital mortality, the decreased incidences of ARDS and hypoxemia and the improvement in PaO2/FIO2 were found in the high PEEP arm.