Pneumoperitoneum affects stroke volume variation in humans

Stroke volume variation (SVV) is affected by many factors. Although elevated intra-abdominal pressure and a pneumoperitoneum have been shown to increase SVV in animals, a recent human study showed that SVV did not change as a pneumoperitoneum was established. However, we considered the results of this study questionable, and we therefore attempted to study whether SVV changes both before and after pneumoperitoneums in humans.

We performed a prospective observational study in 19 patients undergoing cholecystectomy or colectomy while on mechanical ventilation. Immediately before pneumoperitoneum, baseline registrations of variables were obtained (baseline I), which were measured every min for 5 min after the pneumoperitoneum was initiated. Immediately before the pneumoperitoneum was released, another baseline registration of variables was obtained (baseline II); these variables were then measured every min for 5 min.

After the pneumoperitoneum was initiated, there were significant increases in SVV at the 2- to 5-min time points. After release of the pneumoperitoneum, there were significant decreases in SVV at the 1- to 5-min time points.

A pneumoperitoneum increased SVV, which is similar to the findings of previous animal studies but is different from a previous clinical study. Upon release of the pneumoperitoneum, SVV decreased significantly, which is new information. SVV values must be estimated cautiously during a pneumoperitoneum.