Carnivore Restraint & Anesthesia

Question 2

What physiologic effects were observed with application of detmoidine gel to the buccal mucosa of dogs?

Was it an effective sedative?

Answer 2

METHODS: Detomidine gel (2.0 mg/m2) was administered on the buccal mucosa. Cardiopulmonary data and sedation scores were obtained at predetermined times over 180 minutes. Atipamezole (0.1 mg/kg) was administered IM at 150 minutes. Reversal of sedation was timed and scored. Data were analyzed with an ANOVA.

RESULTS: Compared with baseline values, heart rate was lower at 45 to 150 minutes, cardiac output and oxygen delivery were lower at 30 to 150 minutes, and systemic vascular resistance was increased at 30 to 150 minutes. There were no significant changes in Paco2, Pao2, or lactate concentration at any time point, compared with baseline values, except for lactate concentration at 180 minutes. All dogs became sedated; maximum sedation was detected 75 minutes after administration of detomidine. Mean ± SD time to recovery after atipamezole administration was 7.55 ± 1.89 minutes; sedation was completely reversed in all dogs. No adverse events were detected.

Physiologic Effects:

• Significant decrease in RR, CO, and DO2, significant increase in SVR.
  
  • Persisted until reversal.
• Decreased RR attributed to centrally mediated sedation.
• Increased SVR resulted from vasoconstriction.
• Decreased CO and DO2 secondary to bradycardia and increased SVR.
  
  • No significant change in pH, PaCO2, PaO2, HCO3; also lactate until 180 min, then increased.
• Changes in SAP, DAP, MAP over time not observed to be significant, attributed to being dose-dependent.
  
  • Following reversal, MAP and DAP increased from baseline (return to normal homeostasis).
• Clinically important increase in PCV at 180 BPM.
  
  • Splenic contraction secondary to direct sympathetic stimulation or lessening of the sympathetic inhibition that was caused by reversal.

Reference: American Journal of Veterinary Research, 79(12), 1253-1260. 2018. Sedative and cardiopulmonary effects of buccally administered detomidine gel and reversal with atipamezole in dogs. Kasten, J. I., Messenger, K. M., & Campbell, N. B.

Question 3

What effects of transmucosal detomidine gel were observed when administered to ferrets?

Answer 3

Effects of detomidine on ferrets included decreased HR, decreased rectal temp, and piloerection of the tail. Administration of oral TM detomidine at 2 mg/m^2 and 4 mg/m^2 provided successful, rapid, and safe sedation in ferrets.

• Tested two doses – 2 mg/m^2 and 4 mg/m^2. All reversed at 60 minutes.
• Safe and effective for PE and venipuncture. Could be placed into dorsal recovery without manual restraint at 10 minutes. Still had some jaw tone, not deep enough to intubate.
• Onset of sedation much faster vs dogs and horses.
• HR significantly decreased over time.
• One ferret exhibited second-degree AV block, resolved with reversal. Reported with other spp.
• RR decreased at a few time points.
• Rectal temps significantly decreased.
• Alpha 2s decrease body temp due to CNS depression and decreased muscle activity.
• External heating source recommended for prolonged sedation (i.e. for US).
• Most ferrets became hyperglycemic. Reported with other alpha 2s. Alpha 2 receptor activation may inhibit insulin release or stimulate glucagon release to result in a transient hyperglycemia.
• All ferrets exhibited piloerection of the tail after detomidine administration.

Reference:

Phillips, B. E., Harms, C. A., & Messenger, K. M. (2015). Oral transmucosal detomidine gel for the sedation of the domestic ferret (Mustela putorius furo). Journal of exotic pet medicine, 24(4), 446-454.