EVALUATION OF THIOPENTONE-MIDAZOLAM-FENTANYL ANESTHESIA IN PIGS

Induction of anaesthesia in swine by thiopentone (27.1-35.7 mg/kg, mea n 29.9 mg/kg) was followed by bolus doses and continuous infusion of m idazolam and fentanyl (0.90 mg/kg followed by 0.90 mg/kg/h and 0.025 m g/kg followed by 0.025 mg/kg/h, respectively). This produced good anae sthesia and analgesia for up to 2 h in 6 Norwegian Landrace pigs (wt: 17-42 kg), based on responses to painful stimuli elicited by pinching the nasal septum, the mouth, the forefoot and the perineal skin area. The first responses occurred after 110 min of anaesthesia. No signific ant drop in rectal temperature due to the regimen was noted during mon itoring periods (140-180 min). This combined intravenous anaesthetic r egimen gave good anaesthesia and analgesia to pigs for up to 2 h as mo nitored by clinical signs. The regimen may not be sufficient for longe r time periods. We cannot advocate the incorporation of neuromuscular blocking agents in this regimen.