Medetomidine, ketamine, and sevoflurane for anesthesia for injured loggerhead sea turtles: 13 cases (1996-2000)

Objective-To determine safety and efficacy of an anesthetic protocol incorporating medetomidine ketamine, and sevoflurane for anesthesia of injured loggerhead sea turtles. Design-Retrospective study. Animals-13 loggerhead sea turtles. Procedure-Anesthesia was induced with medetomidine (50 mug/kg [22.7 mug/lb], IV) and ketamine (5 mg/kg [2.3 mg/lb], IV) and maintained with sevoflurane (0.5 to 2.5%) in oxygen. Sevoflurane was delivered with a pressure-limited intermittent-flow ventilator. Heart rate and rhythm, end-tidal partial pressure of CO2, and cloacal temperature were monitored continuously; venous blood gas analyses were performed intermittently. Administration of sevoflurane was discontinued 30 to 60 minutes prior to the end of the surgical procedure. Atipamezole (0.25 mg/kg [0.11 mg/lb], IV) was administered at the end of surgery. Results-Median induction time was 11 minutes (range, 2 to 40 minutes; n = 11). Median delivered sevoflurane concentrations 15, 30, 60, and 120 minutes after intubation were 2.5 (n = 12), 1.5 (12), 1.25 (12), and 0.5% (8), respectively. Heart rate decreased during surgery to a median value of 15 beats/min (n = 11). End-tidal partial pressure of CO2 ranged from 2 to 16 mm Hg (n = 8); median blood gas values were within reference limits. Median time from atipamezole administration to extubation was 14 minutes (range, 2 to 84 minutes; n = 7). Conclusions and Clinical Relevance-Results suggest that a combination of medetomidine and ketamine for induction and sevoflurane for maintenance provides safe, effective, controllable anesthesia in injured loggerhead sea turtles.