Low-dose nicardipine during cardiopulmonary bypass improves carotid hemodynamics in CABG patients: a randomized controlled trial.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common complication of coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB), largely associated with cerebral hemodynamic disturbances. Carotid duplex ultrasonography–derived parameters, including peak systolic velocity (PSV-ICA) and end-diastolic velocity (EDV-ICA), provide reliable, noninvasive indicators of cerebral blood flow. This study evaluated whether intraoperative nicardipine infusion improves carotid blood flow and mitigates postoperative cognitive decline. METHODS: In this randomized, double-blind trial, 64 elderly patients undergoing CABG were assigned to receive either continuous low-dose nicardipine (0.2–0.5 µg/kg·min) during CPB (nicardipine group, n = 32) or saline (control group, n = 32). The co-primary endpoints were intraoperative PSV-ICA and EDV-ICA at four predefined time points (T1: pre-anesthesia; T2: surgery initiation; T3: during CPB; T4: post-CPB). Secondary endpoints included regional cerebral oxygen saturation (rScO₂), plasma neuron-specific enolase (NSE), Mini-Mental State Examination (MMSE) scores, vasopressor use, ventilation time, ICU stay, and hospitalization length. RESULTS: Baseline and intraoperative characteristics were comparable. Both groups showed reduced carotid flow velocities during CPB, but recovery of PSV-ICA at the end of CPB was significantly greater with nicardipine (63.7 ± 15.2 vs. 54.3 ± 13.9 cm/s; P = 0.025). EDV-ICA exhibited a similar trend without significant between-group differences. Secondary outcomes (MMSE, NSE) did not differ, and no adverse events occurred. CONCLUSION: Continuous low-dose nicardipine during CPB significantly improved the recovery of PSV-ICA without affecting systemic hemodynamics or increasing adverse events. These findings suggest a potential intraoperative neuroprotective role of nicardipine, warranting confirmation in larger trials with long-term cognitive outcomes.