Duration of etomidate-induced adrenocortical suppression during surgery in dogs

John R. Dodam From the Department of Anatomy, Physiological Sciences, and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27604.

Search for other papers by John R. Dodam in
Current site
Google Scholar
PubMed
Close
 DVM
,
Kris T. Kruse-Elliott From the Department of Anatomy, Physiological Sciences, and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27604.

Search for other papers by Kris T. Kruse-Elliott in
Current site
Google Scholar
PubMed
Close
 DVM
,
David P. Aucoin From the Department of Anatomy, Physiological Sciences, and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27604.

Search for other papers by David P. Aucoin in
Current site
Google Scholar
PubMed
Close
 DVM
, and
Clifford R. Swanson From the Department of Anatomy, Physiological Sciences, and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27604.

Search for other papers by Clifford R. Swanson in
Current site
Google Scholar
PubMed
Close
 DVM, MS

Click on author name to view affiliation information

Summary

Plasma cortisol concentrations were compared in canine surgical patients given etomidate (2 mg/kg of body weight, iv) or thiopental sodium (12 mg/kg, iv) for anesthetic induction. Blood samples to determine plasma concentrations of etomidate were obtained at 0, 5, 10, 15, and 30 minutes and 1, 2, 3, 4, 5, 6, 8, 12, and 24 hours after induction. Adrenocortical function was evaluated before surgery by use of adrenocorticotropic hormone stimulation tests. Dogs in both induction groups had high plasma cortisol concentrations after induction. Dogs given thiopental had a significant increase (P < 0.05) in plasma cortisol concentration from baseline at 2, 3, 4, 5, 6, 8, and 12 hours after induction. Dogs given etomidate had a significant increase (P < 0.05) in plasma cortisol concentration from baseline at 5, 6, and 8 hours after induction. A comparison of plasma cortisol concentrations determined at 2, 3, 4, 5, and 6 hours after induction with thiopental or etomidate revealed a higher (P < 0.05) concentration in dogs given thiopental.

The disposition of etomidate was best described by a 2-compartment model, with a redistribution half-life of 0.12 ± 0.04 minute and a terminal half-life of 1.70 ± 0.27 minute. Plasma cortisol concentrations did not correlate with plasma etomidate concentrations.

We conclude that, compared with thiopental, a single bolus injection of etomidate reduces the adrenocortical response to anesthesia and surgery from 2 to 6 hours after induction. Because cortisol concentrations were significantly higher than baseline, and because cardiopulmonary function is maintained after a single bolus injection of etomidate, it can be considered a safe induction agent in dogs.

Summary

Plasma cortisol concentrations were compared in canine surgical patients given etomidate (2 mg/kg of body weight, iv) or thiopental sodium (12 mg/kg, iv) for anesthetic induction. Blood samples to determine plasma concentrations of etomidate were obtained at 0, 5, 10, 15, and 30 minutes and 1, 2, 3, 4, 5, 6, 8, 12, and 24 hours after induction. Adrenocortical function was evaluated before surgery by use of adrenocorticotropic hormone stimulation tests. Dogs in both induction groups had high plasma cortisol concentrations after induction. Dogs given thiopental had a significant increase (P < 0.05) in plasma cortisol concentration from baseline at 2, 3, 4, 5, 6, 8, and 12 hours after induction. Dogs given etomidate had a significant increase (P < 0.05) in plasma cortisol concentration from baseline at 5, 6, and 8 hours after induction. A comparison of plasma cortisol concentrations determined at 2, 3, 4, 5, and 6 hours after induction with thiopental or etomidate revealed a higher (P < 0.05) concentration in dogs given thiopental.

The disposition of etomidate was best described by a 2-compartment model, with a redistribution half-life of 0.12 ± 0.04 minute and a terminal half-life of 1.70 ± 0.27 minute. Plasma cortisol concentrations did not correlate with plasma etomidate concentrations.

We conclude that, compared with thiopental, a single bolus injection of etomidate reduces the adrenocortical response to anesthesia and surgery from 2 to 6 hours after induction. Because cortisol concentrations were significantly higher than baseline, and because cardiopulmonary function is maintained after a single bolus injection of etomidate, it can be considered a safe induction agent in dogs.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 125 125 26
PDF Downloads 35 35 4
Advertisement