A method to attenuate pneumoperitoneum-induced reductions in splanchnic blood flow

Objective: To determine if increasing nitric oxide bioactivity by inclusion of ethyl nitrite (ENO) in the insufflation admixture would attenuate pneumoperitoneum-induced decreases in splanchnic perfusion. Summary Background Data: Organ blood flow is reduced during pneumoperitoneum and can contribute to laparoscopy-associated morbidity and mortality. Previous attempts to control such decreases in flow have been ineffective. Methods: Laser-Doppler flow probes were placed on the liver and right kidney of anesthetized pigs. After a baseline recording period, animals were insufflated to a final intraperitoneal pressure of 15 mm Hg. Group one received CO₂ (standard practice), whereas group 2 received CO₂ plus 100 ppm ENO. Insufflation was maintained for 60 minutes and then the abdomen was manually deflated; monitoring was continued for another 60 minutes. Results: CO₂ insufflation (n = 5) cut liver blood flow in half; liver flow remained at this level throughout the postinsufflation period. Inclusion of 100 ppm ENO (n = 6) attenuated both the acute and prolonged blood flow decreases. Statistical modeling of the data showed that, on average, liver blood flow was 14.3 U/min higher in the ENO pigs compared with the CO₂ group (P = 0.0454). In contrast, neither treatment significantly altered kidney blood flow (P = 0.6215). Conclusion: The data indicate that ENO can effectively attenuate pneumoperitoneum-induced blood flow decreases within the peritoneal cavity. The result suggests a novel therapeutic method of regulating hemodynamic changes during laparoscopic procedures.