Utility of pleural effusion drainage in the ICU: An updated systematic review and META-analysis

Purpose: The effects on the respiratory or hemodynamic function of drainage of pleural effusion on critically ill patients are not completely understood. First outcome was to evaluate the PiO 2 /FiO 2 (P/F) ratio before and after pleural drainage. Secondary outcomes: evaluation of A-a gradient, End-Expiratory lung volume (EELV), heart rate (HR), mean arterial pressure (mAP), left ventricular end-diastolic volume (LVEDV), stroke volume (SV), cardiac output (CO), ejection fraction (EF), and E/A waves ratio (E/A). A tertiary outcome: evaluation of pneumothorax and hemothorax complications. Materials and methods: Searches were performed on MEDLINE, EMBASE, COCHRANE LIBRARY, SCOPUS and WEB OF SCIENCE databases from inception to June 2018 (PROSPERO CRD42018105794). Results: We included 31 studies (2265 patients). Pleural drainage improved the P/F ratio (SMD: −0.668; CI: -0.947–0.389; p <.001), EELV (SMD: -0.615; CI: -1.102–0.219; p =.013), but not A-a gradient (SMD: 0.218; CI: -0.273-0.710; p =.384). HR, mAP, LVEDV, SV, CO, E/A and EF were not affected. The risks of pneumothorax (proportion: 0.008; CI: 0.002–0.014; p =.138) and hemothorax (proportion: 0.006; CI: 0.001–0.011; p =.962) were negligible. Conclusions: Pleural effusion drainage improves oxygenation of critically ill patients. It is a safe procedure. Further studies are needed to assess the hemodynamic effects of pleural drainage.