MEDIAN EFFECTIVE DOSE OF PROPOFOL REQUIRED FOR INDUCTION OF ANESTHESIA IN GOATS

Objective-To determine the median effective dose (ED50) of propofol re quired for induction of anesthesia in goats and the frequency of myocl onic activity and apnea associated with propofol administration. Desig n-Clinical trial. Animals-28 healthy mature goats. Procedure-ED50 was determined by use of the up-and-down method. The first goat was given 4 mg of propofol/kg (1.8 mg/lb) of body weight, IV. Dose was increased by 25% for the next goat if endotracheal intubation was not possible and decreased by 20% if it was. For each subsequent goat, dose was det ermined on the basis of response of the previous goat. The ED50 was ca lculated by use of probit analysis. Induction time, frequency and dura tion of apnea, frequency of myoclonus, and other adverse effects were recorded. Results-ED50 was determined to be 5.1 mg/kg (2.3 mg/lb). Mea n (+/- SD) induction time was 23.2 +/- 4.7 seconds. Apnea was observed in 27 of 28 goats; mean (+/- SD) duration of apnea was 72.9 +/- 38.3 seconds. Dose did not correlate with duration of apnea. Myoclonic acti vity was observed in 16 of 28 goats; frequency of myoclonus was not as sociated with dose. Cyanosis, regurgitation, and signs of pain during injection were not observed. Clinical Implications-Administration of p ropofol at 5.1 mg/kg (2.3 mg/lb), IV, should permit endotracheal intub ation in half of unpremedicated, healthy, mature goats. Myoclonus and apnea were associated with propofol administration.