[Falls in PaO2 owing to prostaglandin E1 infusion in an obese patient undergoing laparoscopic cholecystectomy--detection by intra-arterial blood gas monitoring].

We monitored the changes of arterial blood gas tensions using a continuous blood gas monitor (Paratrend-7) in an obese patient who underwent laparoscopic cholecystectomy. We could observe continuous changes in PaO2 caused by prostaglandin E1 (PGE1) infusion. Suppression in hypoxic pulmonary vasoconstriction due to PGE1 would lead to falls in PaO2. Intra-arterial blood gas monitoring is quite useful in such a situation in which large .VA/.Q changes are expected due to infusion of PGE1 in an obese patient with high intra-abdominal pressure.