Air in the insufflation tube may cause fatal embolizations in laparoscopic surgery: an animal study

Background

The aim of this study was to evaluate the risk of an air embolization with the volume of the insufflation tube during induction of laparoscopy. A further objective was to determine the LD₅₀ of air in young piglets.

Methods

End-tidal carbon dioxide pressure ( $ P_{{{text{CO}}_{2} ,{text{et}}}} $ ), pulmonary arterial pressure (P _pa), heart rate (f _c), and mean arterial pressure (P _{a carot}) were measured in 17 piglets divided into three groups: group 1 (n = 6), bolus application (CO₂ embolization, followed by air embolization, 2 mL/kg each), group 2 (n = 7), continuous air embolization (30 min, 0.2 mL/kg/min), and group 3 (n = 4), continuous CO₂ embolization (30 min, 0.4 mL/kg/min).

Results

All animals survived CO₂ embolism. Air embolization as a bolus (2 mL/kg) or with an accumulated volume of 3.1 mL/kg led to death. Decreases in $ P_{{{text{CO}}_{2} ,{text{et}}}} $ indicated air or massive CO₂ embolization only. There was a good correlation between $ P_{{{text{CO}}_{2} ,{text{et}}}} $ and P _pa in case of air embolization (r = ?0.80, p < 0.0001). In contrast, no dependency was recognized during CO₂ embolism (r = ?0.17, p = 0.2).

Conclusions

In order to minimize the lethal risk of gas embolization, the insufflation system has to be completely filled with CO₂ before connecting to the patient.