Effect of diltiazem on kidney function during laparoscopic surgery

Background  Pneumoperitoneum is known to be associated with transient impairment in kidney function. This study was designed to investigate the effect of diltiazem on acute kidney injury during positive pneumoperitoneum in patients undergoing laparoscopic surgery. Methods  Thirty-two patients of American Society of Anesthesiologists (ASA) 1 and 2 physical status undergoing laparoscopic surgery were randomly divided into control (normal saline infusion) and diltiazem groups (diltiazem 2 μg/kg/min). Urinary flow, urinary sodium excretion, creatinine clearance (CrCl), and hemodynamic variables were determined during pneumoperitoneum and at postoperative 2 h. CrCl using Cockcroft–Gault equation was calculated before surgery (baseline), and at postoperative days 1 (POD1) and 2. Results  The hemodynamic parameters were similar in both groups. CrCl during pneumoperitoneum in the diltiazem group was significantly higher than that in the control group (90.8 ± 49.0 ml/min/1.73 m² vs. 54.2 ± 31.6 ml/min/1.73 m²) (P = 0.026). CrCl calculated with Cockcroft–Gault equation was similar in both groups at baseline, POD1, and POD2. Urinary flow was significantly increased in both groups at postoperative 2 h compared with that during pneumoperitoneum. Conclusion  Continuous infusion of diltiazem 2 μg/kg/min prevented the decrease in CrCl during pneumoperitoneum without hemodynamic derangement. Although the decrease in CrCl was transient in patients with normal kidney function in this study, diltiazem may be used to prevent further kidney injury in those with elevated CrCl during laparoscopic surgery.