Reversal of adverse hemodynamic effects of pneumoperitoneum by pressure equilibration

Hypothesis: The creation of positive-pressure pneumoperitoneum during laparoscopic operations can lead to adverse hemodynamic changes, mainly decreased cardiac output. We hypothesized that pneumatic compression sleeves worn on the legs during pneumoperitoneum could abolish the pressure gradient between the abdominal cavity and the legs and so eliminate these adverse hemodynamic changes. Design: Prospective, randomized, controlled clinical trial with an additional calibration group. Setting: A regional referral center. Patients: Forty-five consecutive patients undergoing laparoscopic cholecystectomy who developed hemodynamic changes on induction of positive-pressure pneumoperitoneum were randomized to 3 groups. Interventions: Low-pressure, nonsequential pneumatic compression sleeves, wrapped around the legs, were used to equilibrate the pressure gradient in the study group and to gradually exceed it in the calibration group. In the control group, no sleeves were used. Main Outcome Measures: Transesophageal Doppler cardiac output, stroke volume, and systemic vascular resistance were monitored noninvasively. Results: The creation of positive-pressure pneumoperitoneum caused a significant decrease of cardiac output and stroke volume and increased systemic vascular resistance. In the experimental groups of patients, pressurizing the sleeves to the pneumoperitoneal pressure caused a significant increase of cardiac output (from 4.82 to 6.74 L/min), increased stroke volume, and decreased systemic vascular resistance (P<.001). This was not seen in the control group. Additional gradual pressure increase in the sleeves of the calibration group produced no further improvement. Releasing the pressure abolished the hemodynamic advantages. Conclusions: Applying pressure on the legs equivalent to the positive-pressure pneumoperitoneum improves hemodynamic performance during pneumoperitoneum by nullifying the pressure gradient that is responsible for the adverse consequences. This might be of major practical value, especially for cardiac patients undergoing prolonged laparoscopic operations.