Ten (5 female, 5 male) captive-born cougars (Felis concolor) weighing 45 ± 11 kg (mean ± SD) were immobilized to determine the cardiopulmonary effects of an IM medetomidine-ketamine combination. Medetomidine (43.4 ± 5.4 ug/kg IM) - ketamine (2.2 ± 0.2 mg/kg IM) administered via a remote drug delivery system produced recumbency in 6 ± 2 minutes and anesthesia in 10 ± 3 minutes. Muscle relaxation was considered excellent during the immobilization period. Heart rate, respiratory rate, functional oxygen hemoglobin saturation (SpO2) and end tidal-CO2 concentration were determined every minute for the first 5 minutes and every 5 minutes thereafter for 30 minutes. Statistical analysis was performed by ANOVA for repeated measures in order to compare the means for each response variable. Where a significant difference was identified the Duncan's post-hoc test was used. P < 0.05 was accepted as statistically significant. No significant changes in heart rate (HR15min, 88 ± 13 beats/minute) were observed during the anesthetic event. A significant (P < 0.05) decrease in respiratory rate when compared to values obtained at 1 minute (20 ± 6 breaths/minute) was seen at 2 minutes (14 ± 2 breaths/minute) of immobilization and thereafter. Indirect measured arterial blood pressures were well maintained and no significant changes over time were detected. Pulse oximeter readings indicated hypoxemia with functional oxygen hemoglobin saturation (SpO2) < 90%, during the first 2 minutes of immobilization. For the remainder of the immobilization, SpO2 values were > 90%. End-tidal CO2 concentrations were < 35 mmHg throughout the procedure. Arterial blood samples collected at 1, 15 and 30 minutes of immobilization indicated no periods of hypoxemia (PO215min, 103 ± 8 mmHg). Reversal with atipamezole (216 ± 27 ug/kg, half IV and half SQ) given 30 minutes after induction of anesthesia was rapid and uneventful. Time to sternal recumbency or standing was 4 ± 2 minutes. Medetomidine-ketamine at the dosage used in this study are effective agents for rapid immobilization of cougars for short procedures or prior to inhalation anesthesia.
©1998, The American College of Veterinary Anesthesiologists, all rights reserved.
This page is hosted for the American College of Veterinary Anesthesiologists by the Informatics Program of the Virginia-Maryland Regional College of Veterinary Medicine.
. Direct your questions or comments about the web page to our site host.