Fig. 4From: Hemolysis and cardiopulmonary bypass: meta-analysis and systematic review of contributing factorsForest plot of published studies comparing plasma free hemoglobin (PFHb) between vacuum-assisted venous drainage (VAVD) and gravity-assisted venous drainage (GAVD) using random effects analysis. Data presented as Mean Difference (MD) with 95% Confidence Interval (CI)Back to article page