The duration of hemodynamic depression during laparoscopic cholecystectomy

Background: We previously evaluated the effects of pneumoperitoneum and patient position on hemodynamics during laparoscopic cholecystectomy and found that patient position had no effect on cardiac index (CI), stroke volume (SV), and left ventricular end diastolic volume (LVEDV). Analysis of that data showed that the hemodynamic depression associated with pneumoperitoneum was transient with values trending toward baseline during the operative period. The purpose of this study was to examine the duration of the adverse hemodynamic effects of pneumoperitoneum during laparoscopic cholecystectomy. Methods: Thirty-eight patients undergoing laparoscopic cholecystectomy by a single surgeon were enrolled in the study. Hemodynamic data was collected via a transthoracic bioimpedance monitor. Baseline readings were taken prior to establishing pneumoperitoneum. Data was then collected continuously over the course of each case. Patients were compared to their baseline values. Data was analyzed every 5 min with the paired t-test used to determine statistical significance. Results: All parameters were compared to baseline values. Baseline was defined as 5 min after the induction of anesthesia. With insufflation to 15 mmHg CO2, CI fell from a baseline value of 2.82 L/min/m(2) to 2.66 L/min/m(2) (p = 0.04), SV from 71.58 mL to 65.44 mL (p = 0.002), and LVEDV from 111.46 mL to 102.68 mL (p = 0.003). At 5 min, all values were further depressed. At 10 min all values were no longer significantly different from baseline. Values returned to baseline at 15 min and did not walver for the remainder of each case or the next 35 min. Conclusion: Patients undergoing laparoscopic cholecystectomy experience significant hemodynamic depression with pneumoperitoneum. These changes are short-lived and lose their statistical significance at 10 min from the time a patient undergoes pneumoperitoneum.