Anesthetic Recovery Following Intramuscular Epinephrine in the Loggerhead Sea Turtle (Caretta caretta)
Abstract
Prolonged anesthetic recovery time is a common complication of chelonian inhalant anesthesia1,2,3 and may be caused, in part, by right to left intracardiac shunting of blood. Administration of epinephrine may decrease intracardiac shunting and, thus, may shorten anesthetic recovery time. Significantly decreased anesthetic recovery times following epinephrine administration were recently demonstrated in the common snapping turtle.4 The objective of this study was to assess inhalant anesthetic recovery time following epinephrine administration compared to a saline control in loggerhead sea turtles (Caretta caretta). Using a prospective, randomized, blinded, crossover design, six sea turtles were induced with IV alfaxalone, intubated, manually ventilated with 3.5% isoflurane inhalant in 100% oxygen for 90 minutes, and administered either IM epinephrine 0.1 mg/kg or IM saline 0.1 mL/kg. Isoflurane and oxygen administration were then discontinued and turtles were manually ventilated on room air until extubation. Physiologic parameters, sedation scores, end-tidal carbon dioxide and isoflurane concentrations, time to first movement, and time to extubation were recorded throughout the anesthetic episode. While differences were not statistically significant, time to first movement and time to extubation were faster in 5/6 and 4/6 turtles following epinephrine administration compared to saline, respectively, with time to extubation at least 30 minutes faster in all four turtles (range 31–123 minutes). No adverse effects secondary to epinephrine administration were noted. Intramuscular epinephrine may reduce the time to recovery following inhalant anesthesia in loggerhead sea turtles.
Acknowledgements
The authors extend thanks to the following individuals for their contribution to this project: Anthony Cerreta, Emily Christiansen, Eli Cohen, Scott Hammer, Ashley Kirby, Sarah Ostenkamp, Bailey Reynolds, Gretchen Schaffe, Kristen Ward, and Lori Westmoreland. The authors would further like to thank The Lohmann Lab at the University of North Carolina at Chapel Hill for turtle provision; without them this project would not have been possible. Research was conducted under North Carolina Wildlife Resources Commission Endangered Species Permits 16ST41 and 16ST42.
* Presenting author
+ Student presenter
Literature Cited
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