Hemodynamic changes during laparoscopic cholecystectomy monitored with transesophageal echocardiography

Abstract

Although pneumoperitoneum has been well tolerated in a predominantly healthy population, there is concern that an increased intraperitoneal pressure may be poorly tolerated in patients with marginal cardiopulmonary function. The purpose of this study was to demonstrate noninvasively the hemodynamic effects of carbon dioxide pneumoperitoneum utilizing biplane transesophageal echocardiography. Fourteen otherwise-healthy patients undergoing nonemergent laparoscopic cholecystectomy were studied using bi-plane transesophageal echocardiography under a standardized anesthetic protocol utilizing isoflurane, fentanyl, and vecuronium bromide. Endtidal CO₂, oxygen saturation, cardiac rhythm, temperature, and blood pressure were monitored noninvasively. Minute ventilatory volume was adjusted as needed to keep end-tidal CO₂ less than 38 mmHg. Data were recorded at baseline, following abdominal insufflation to 15 mmHg with CO₂, with head-up tilt of 20°, following exsufflation, and with the patient level. Significance was determined using a paired Student t-test. Insufflation to 15 mmHg decreased cardiac index (C.I.) by 3% (3.34 to 3.23 l/min/m²) while both heart rate (HR) and mean arterial pressure (MAP) increased (by 7% and 16%), respectively, and stroke volume index decreased by 10% (from 51.6 to 46.6 ml/beat/m²). Head-up tilt of 20° further decreased CI to 2.98 l/min/m² (−11%) and SVI to 40.3 ml/beat/m² (−22%) while HR increased by a total of 14% and MAP by 19%. As laparoscopic techniques are applied to a broader population, the impact of small but significant decrements in cardiac function become increasingly important. This study demonstrates that the combination of CO₂ pneumoperitoneum and the reverse Trendelenburg position does adversely effect cardiac output.