BACKGROUND: Laparoscopic cholecystectomy and gynecologic pelviscopy need to induce pneumoperitoneum to allow visualization of the operative field, but the former requires a head-up position whereas the latter needs a Lithotomy-Trendelenburg position. The authors observed hemodynamic changes using an esophageal doppler monitor in both cases. METHODS: Eight females planned for laparoscopic cholecystectomy were assigned to Group 1 and 10 females for gynecologic pelviscopy were assigned to Group 2. Thiopental (5 mg/kg) and vecuronium (0.1 mg/kg) were used to induce general anesthesia. 50% O2-N2O and 1.5 vol.% isoflurane were used to maintain anesthesia. Mechanical ventilation was used with a tidal volume of 10 ml/kg and a respiratory rate of 12 breaths per minute. Mean arterial pressure, heart rate, end-tidal CO2 and peak airway pressure were measured and cardiac output, corrected flow time, and peak velocity were monitored using an esophageal doppler monitor in each group after inducing anesthesia, CO2 inflation, position change, and CO2 deflation. RESULTS: Mean arterial pressure increased in each group while changing position. No significant changes in the heart rate were observed in each group. End-tidal CO2 increased in each group after changing position, and remained elevated even with position reversal and deflation. Peak airway pressure was elevated in each group after CO2 inflation and increased more so with changing posture in group 2 (post inflation: 18.5 +/- 1.4 cmH2O, after position change: 21.4 +/- 2.0 cmH2O). Cardiac output and cardiac index were reduced after the induction of pneumoperitoneum in each group, and reduced more on changing posture in group 2 (CO: 5.9 +/- 2.0 L/min vs. 4.4 +/- 1.5 L/min, CI: 3.7 +/- 1.4 L/min/m2 vs. 2.7 +/- 1.1 L/min/m2). Stroke volume also reduced after changing posture in each group. Corrected flow time was not changed, but peak velocity decreased after CO2 inflation in each group (group 1: 97.4 +/- 30.0 cm/s vs. 78.9 +/- 27.3 cm/s, group 2: 111.9 +/- 14.1 cm/s vs. 88.3 +/- 12.6 cm/s). CONCLUSIONS: The Lithotomy-Trendelenburg position can augment the hemodynamic changes resulting from pneumoperitoneum. Therefore, additional caution is required in patients with cardiovascular disease who are undergoing gynecologic pelviscopy.