Objectives: To determine the effects of pump priming fluid choice on platelets, fluid balance, and clinical outcomes.
Design: Meta-analysis of controlled clinical trials. Primary endpoints were platelet counts, colloid oncotic pressure, on-bypass fluid balance, postoperative weight gain, and colloid usage.
Setting: Cardiac surgery with cardiopulmonary bypass.
Patients: Adult and pediatric patients undergoing cardiac surgery, including coronary artery bypass grafting, valve procedures, and correction of congenital cardiac anomalies.
Interventions: Extracorporeal circuit priming with either albumin or crystalloid.
Measurements and results: The meta-analysis included 21 controlled trials with 1,346 total patients. Albumin prime significantly reduced the on-bypass drop in platelet counts. The pooled weighted mean difference in platelet count drop with albumin versus crystalloid prime was -23.8 x 10(9)/L (confidence interval [CI], -42.8 to -4.7 x 10(9)/L). The colloid oncotic pressure decline was also smaller when albumin rather than crystalloid was used for priming, with a pooled weighted mean difference of -3.6 mm Hg (CI, -4.8 to -2.3 mmHg) during bypass and -2.0 mmHg (CI, -2.9 to -1.1 mmHg) after surgery. Albumin prime correspondingly reduced on-bypass positive fluid balance (-584 mL; CI, -819 to -348 mL) and postoperative weight gain (-1.0 kg; CI, -0.6 to -1.3 kg) compared with crystalloid. Postoperative colloid usage was lower with albumin than crystalloid prime (-612 mL; CI, -983 to -241 mL).
Conclusions: Albumin prime better preserves platelet counts than crystalloid. Albumin also favorably influences colloid oncotic pressure, on-bypass positive fluid balance, postoperative weight gain, and colloid usage. The clinical significance of these observations merits further investigation.