Does the roller pump adjustment in cardiopulmonary bypass settings influence hemolysis?

INTRODUCTION: Roller pumps are widely used in procedures involving cardiopulmonary bypass (CPB) due to their ease of operation and maintenance, safety, and cost. Several studies in the literature have compared the use of roller pumps with centrifugal pumps, but the influence of the roller pump adjustment on hemolysis has been poorly explored.

METHODS: Measurements of hemolysis rates were carried out in 86 patients. The pump was adjusted by the dynamic calibration method, which was performed by an auxiliary device, and the patients were grouped according to the pump calibration: Group 1 (n = 20) 75 mmHg; Group 2 (n = 24) 150 mmHg; Group 3 (n = 22) 300 mmHg and Group 4 (n = 21) 450 mmHg. The hemolysis rates were measured at 4 different times during CPB (T0: before the surgical procedure; T1: 5 minutes after the start of CPB; T2: 30 minutes of CPB; and T3: 5 minutes after the CPB procedure). Hemolysis rates were calculated between the time intervals T0-T1, T1-T2, and T0-T3.

RESULTS: No difference in hemolysis rates was observed between the groups (p>0.31). During the first 5 minutes of CPB, hemolysis represented 35.5% of the total hemolysis and no significant difference was found between groups (p>0.60).

CONCLUSIONS: Calibration of roller pumps by the dynamic method did not influence the hemolysis rates. Additionally, the hemolysis during the first 5 minutes of CPB accounted for ~1/3 of the total hemolysis.