Continuous monitoring of cardiac output during pneumoperitoneum by esophagal Doppler

Objective

The recognition of hemodynamic disturbances during an apparently uneventful surgery is important. Therefore, we applied esophageal Doppler monitoring (EDM) to examine cardiovascular events caused by insufflation during laparoscopy.

Methods

Twenty-three patients undergoing laparoscopic cholecystectomy were studied. EDM readings were taken, starting 10 min after induction of anesthesia, every 3 min throughout pneumoperitoneum, and 10 min after exsufflation.

Results

During pneumoperitoneum, the cardiac output was significantly lower and the systemic vascular resistance significantly higher than either before or after insufflation. The semi-continuous EDM revealed that, despite the sharp decrease in cardiac output upon insufflation, during pneumoperitoneum it recovered gradually in many patients. The increase ranged from 4% to 84%. In about two-thirds of the patients the final values of cardiac output during pneumoperitoneum were within ± 10% of the post-exsufflation values. In three patients (13%), however, there was a substantial decline of cardiac output during pneumoperitoneum. Obese individuals exhibited a larger proportional recovery of the cardiac output during pneumoperitoneum (P = 0.009). No gender or age dependence was noted, and the duration of surgery or ASA grade was not correlated with the recovery, nor was the absolute drop in cardiac output upon insufflation.

Conclusions

The findings suggest that, after the initial decreases of venous and portal return, a compensating mechanism, responsible for the subsequent relief of cardiac output depression, becomes effective. The findings demonstrate the utility of EDM for continuous monitoring during laparoscopy, especially in high-risk patients.