RESUMEN
BACKGROUND: There are several reports on the application of variable degrees of vacuum pressure to hardshell venous reservoirs. The aim of the current study was to compare the hemolytic effects of vacuum-assisted venous drainage (VAVD) at two different vacuum levels with the classical gravity siphon method. METHODS: A prospective, equally randomized (1: 1: 1), parallel group study was performed in elective coronary artery bypass grafting (CABG) operations. PATIENTS: (n = 162) were divided into three groups: gravity siphon (group 1, n = 55), VAVD at -40 mmHg (group 2, n = 55) and VAVD at -80 mmHg (group 3, n = 52). Hemolysis tests were performed at 2, 24 and 48 h following the operations. RESULTS: There were no deaths in this study. Plasma-free hemoglobin (PfHb) levels showed a difference at 2 h (p < 0.001) compared to 24 h (p = 0.02) between the groups. Haptoglobin (Hp) levels also revealed hemolysis in groups 2 and 3 at all sampling times. CONCLUSIONS: Constant negative suction at -80 mmHg during elective coronary bypass operations caused more hemolysis. We do not recommend a constant suction of -80 mmHg for VAVD.