The Effect of the Pressure-Volume Curve for Positive End-Expiratory Pressure Titration on Clinical Outcomes in Acute Respiratory Distress Syndrome: A Systematic Review

Purpose: Methods to optimize positive end-expiratory pressure (PEEP) in acute respiratory distress syndrome (ARDS) remain controversial despite decades of research. The pressure-volume curve (PVC), a graphical ventilator relationship, has been proposed for prescription of PEEP in ARDS. Whether the use of PVC's improves survival remains unclear. Methods: In this systematic review, we assessed randomized controlled trials (RCTs) comparing PVC-guided treatment with conventional PEEP management on survival in ARDS based on the search of the National Library of Medicine from January 1, 1960, to January 1, 2010, and the Cochrane Central Register of Controlled Trials. Three RCTs were identified with a total of 185 patients, 97 with PVCguided treatment and 88 with conventional PEEP management. Results: The PVC-guided PEEP was associated with an increased probability of 28-day or hospital survival (odds ratio [OR] 2.7, 95% confidence interval [CI] 1.5, 4.9) using a random-effects model without significant heterogeneity (I-2 test: P - .75). The PVC-guided ventilator support was associated with reduced cumulative risk of mortality (-0.24 (95% CI -0.38, -0.11). The PVC-managed patients received greater PEEP (standardized mean difference [SMD] 5.7 cm H2O, 95% CI 2.4, 9.0) and lower plateau pressures (SMD -1.2 cm H2O, 95% CI -2.2, -0.2), albeit with greater hypercapnia with increased arterial pCO2 (SMD 8 mm Hg, 95% CI 2, 14). Weight-adjusted tidal volumes were significantly lower in PVC-guided than conventional ventilator management (SMD 2.6 mL/kg, 95% CI -3.3, -2.0). Conclusion: This analysis supports an association that ventilator management guided by the PVC for PEEP management may augment survival in ARDS. Nonetheless, only 3 randomized trials have addressed the question, and the total number of patients remains low. Further outcomes studies appear required for the validation of this methodology.