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.

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.

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).

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.