Cardiac function during steep Trendelenburg position and CO2 pneumoperitoneum for robotic-assisted prostatectomy: a trans-oesophageal Doppler probe study.

Background: Haemodynamic changes associated with pneumoperitoneum and steep Trendelenburg position were investigated in non-obese, ASA I-II males, using general anaesthesia (sevoflurane in air/O2, 40%) undergoing robotic-assisted laparoscopic prostatectomy.

Methods: A trans-oesophageal echo-Doppler probe (Arrow International) measured cardiovascular changes in heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), systemic vascular resistance (SVR), stroke volume (SV) and aortic diameter (AoD) in 35 of 37 males. Assessments were conducted after induction of general anaesthesia in: the supine position; at 45 degrees Trendelenburg; Trendelenburg + pnuemoperitoneum (intra-abdominal 15 mmHg); and at the end of surgery in the supine position.

Results: The Trendelenburg position increased stroke volume. Trendelenburg position + pneumoperitoneum increased MAP and SVR and decreased AoD.

Conclusions: Pneumoperitoneum and steep Trendelenburg position significantly increase MAP and SVR. Trendelenburg position increased stroke volume. Pneumoperitoneum decreases aortic diameter. No significant changes in cardiac output or stroke volume were noted.