Effects of posture and prolonged pneumoperitoneum on hemodynamic parameters during laparoscopy

The present prospective study was designed to evaluate hemodynamic changes associated with head-down positioning and prolonged pneumoperitoneum during totally endoscopic robot-assisted radical prostatectomy.

Ten American Society of Anesthesiologists (ASA) physical status I-III patients undergoing totally endoscopic robot-assisted radical prostatectomy were enrolled in the study. Invasive hemodynamic parameters were measured by transpulmonary arterial thermodilution using the PiCCO system with a femoral artery catheter. Cardiac index (CI), heart rate (HR), mean arterial pressure (MAP), systemic vascular resistance index (SVRI), intrathoracic blood volume (ITBV), and central venous pressure (CVP) were recorded with the patient in the supine position, after head-down tilt, intraoperatively after 30 min, 1 h, 2 h, 3 h, and 4 h of pneumoperitoneum at an insufflation pressure of 12 mmHg, after deflation still with head-down positioning, and finally, with the patient in the supine position.

Placing the patient in the Trendelenburg (head-down) position caused a significant increase in CVP (from 9.9 +/- 3.4 to 15.1 +/- 2.3 mmHg), whereas all other hemodynamic parameters remained nearly unaffected. The induction of pneumoperitoneum resulted in a significant increase in MAP (from 74.9 +/- 12.9 to 95.4 +/- 11.9 mmHg). No other parameter was affected. Even at 4 h of pneumoperitoneum only mild hemodynamic changes were observed. After release of the pneumoperitoneum with the patient still in the head-down position, HR (49.0 +/- 4 versus 63.9 +/- 12.4 min(-1)) and after placing the patient in the supine position, CI (2.4 +/- 0.2 versus 3.3 +/- 0.7 l min(-1 )m(-2)) increased significantly, whereas CVP returned to baseline values.

Patients undergoing totally endoscopic radical prostatectomy with 4 h of pneumoperitoneum in the Trendelenburg position experienced no significant hemodynamic depression during posture and pneumoperitoneum.