THE EFFECTS OF PULSATILE FLOW ON RENAL TISSUE PERFUSION DURING CARDIOPULMONARY BYPASS

Abstract

Purpose: This study is to directly compare the effect of pulsatile versus nonpulsatile blood flow to renal tissue perfusion in extracorporeal circulation by using a tissue perfusion measurement system. Methods: Total cardiopulmonary bypass circuit was constructed to twelve Yorkshire swines, weighing 20–30kg. Animals were randomly assigned to group I (n=6, nonpulsatile centrifugal pump) or group II (n=6, pulsatile T-PLS pump). A probe of the tissue perfusion measurement system (Q-Flow™ 500) was inserted into the renal parenchymal tissue. Extra-corporeal circulation was maintained for an hour at a pump flow of 2 thin after aortic cross-clamping. Tissue perfusion flow of the kidney was measured at baseline (before bypass) and every 10 minutes after bypass. Serologic parameters were collected at baseline and 60 minutes after bypass. Results: Baseline parameters were not different between the groups. Renal tissue perfusion flow was substantially higher in the pulsatile group throughout bypass (ranged 48.5–64.1 in group I vs. 51.0–88.1 mL/min/100gin group 11). The difference was significant at 30 minutes bypass (47,5±18.3 in group I vs. 83.4±28.5 mL/min/100g in group II; p=0.026). Serologic parameters including plasma free hemoglobin, blood urea nitrogen, and creatinine showed no differences between the groups at 60 minutes after bypass (p=NS). Pulsatile flow is more beneficial to tissue perfusion of the kidney in short-term extracorporeal circulation. A further study is suggested to observe the effects to other vital organs or long-term significance.