Nicardipine Effects on Renal Function During Spine Surgery.

Study Design: Single-center, prospective, randomized, and single-blinded clinical trial was conducted in patients (n = 64) undergoing anterior or posterior spinal interbody fusion. Objective: To investigate the renal protective effect of nicardipine during deliberate hypotension for spine surgery by measuring creatinine clearance (Ccr), serum cystatin C, urine output, and fractional excretion of sodium (FENa). Summary of Background Data: Deliberate hypotension during spine surgery may result in ischemic tissue damage of the kidney. Nicardipine is reported to dilate the renal artery and increase glomerular filtration rate. Previous studies reported the renal protective effect of nicardipine during cardiac surgery under cardiopulmonary bypass and robot-assisted laparoscopic surgery. Materials and Methods: Patients were randomized to receive nicardipine (nicardipine group, n = 32) or normal saline (control group, n = 32). Deliberate hypotension of mean arterial pressure at 50-65 mm Hg was maintained during surgery. Ccr, serum cystatin C, urine output, and FENa were measured before surgery, after surgery, and postoperative day 1 (POD1). The RIFLE (risk, injury, failure, loss, and end stage renal disease) criteria of the patients were evaluated. Results: In the nicardipine group, Ccr at POD1 was increased compared with that after surgery. In both groups, serum cystatin C at POD1 was decreased compared with that before surgery and urine output at POD1 was decreased compared with that after surgery. FENa at POD1 in the control group was higher than that in the nicardipine group and was increased compared with that after surgery. Using RIFLE criteria, 6 patients in the control group and 2 patients in the nicardipine group were classified as having acute kidney injury. Conclusions: Nicardipine increased Ccr and attenuated the increase in FENa at POD1 in patients undergoing spine surgery under deliberate hypotension.