THE INFLUENCE OF ISOFLURANE ANAESTHESIA ON INTESTINAL PERMEABILITY IN HEALTHY DOGS.

This study investigated the most appropriate blood sampling time for determining the lactulose/mannitol (L/M) index, and whether isoflurane anaesthesia increases intestinal permeability in dogs, in terms of changes in the L/M index. Six dogs were given 100 ml of sugar solution (3.6 g lactulose and 3.4 g mannitol) with orogastric tube. Blood samples for determination of basal plasma L/M index were taken 90, 120, and 180 minutes later. The next day, the dogs were administered methadone, induced with midazolam mixed with ketamine, followed immediately by propofol, and anaesthesia maintained with isoflurane in oxygen for 200 minutes. The same sugar solution as the day before was administered at the end of anaesthesia and 12 and 24 hours postanaesthesia. Blood samples were taken 90, 120 and 180 minutes after administration of sugar solution. HPLC-MS was used for plasma determination of lactulose and mannitol and the results expressed as L/M index. The highest concentrations of lactulose and mannitol were detected 120 minutes after administration of sugar solution. Lactulose/mannitol index significantly increased at the end of anaesthesia, regardless the sampling time, when compared to basal values from non-anaesthetized dogs. The increase of L/M index due to anaesthesia with isoflurane was short-lived as there was no significant difference between L/M index at 12 hours after the anaesthesia and basal values. The most appropriate blood sampling time for determining the L/M index is 120 minutes after oral administration of dual sugar solution. [ABSTRACT FROM AUTHOR]