THE DETECTION OF CARBON-DIOXIDE EMBOLISM DURING LAPAROSCOPY IN PIGS -A COMPARISON OF TRANSESOPHAGEAL DOPPLER AND END-TIDAL CARBON-DIOXIDE MONITORING

Background: The aim of the study was to compare the value of transesop hageal Doppler and end-tidal carbon dioxide monitoring to detect venou s carbon dioxide embolism in pigs during laparoscopic cholecystectomy. Method: Ten pigs were anesthetized under constant ventilation, and in strumented for laparoscopic cholecystectomy. CO2 pneumoperitoneum was performed at 15 mmHg and then, successive increased intravenous gas bo luses of 0.1 to 4 ml/kg injected through the femoral vein using a 55-m m long catheter. The responses indicative of embolism were defined as: 1) a change in Doppler tone placed facing the junction of the right a trium and inferior vena cava; 2) a change in end-tidal CO2 greater tha n or equal to 0.4 kPa. Results: Doppler was more sensitive in detectin g 0.1, 0.2 and 0.4 ml/mg of CO2 embolism than end-tidal CO2 (P<0.05). Over 0.4 ml/mg no differences in sensitivity were found but the Dopple r signal modifications occurred earlier than the changes in end-tidal CO2. Moreover, these changes always consisted of a reduction of the va lue. Conclusion: During laparoscopic cholecystectomy in pigs, transeso phageal Doppler was a highly sensitive monitor which provided an earli er detection of CO2 embolism and at lower doses than end-tidal CO2 mon itoring. (C) Acta Anaesthesiologica Scandinavica 41 (1997).