Abstract
A 2-year-old, 87 kg, male California sea lion (CSL), and 15-year-old, 149 kg, male, South African fur seal (SAF) underwent elective procedures (castration with diagnostics and bilateral lensectomy, respectively). Pre-surgical blood and physical analysis were "normal".
CSL was given midazolam (0.15 mg/kg) with butorphanol (0.1 mg/kg) IM, causing some excitement. Anesthesia with intubation was induced by mask sevoflurane. SAF was immobilized with medetomidine (0.01 mg/kg), midazolam (0.2 mg/kg) and butorphanol (0.08 mg/kg) IM, intubated and placed on isoflurane.
Jugular venous catheterization was successful in CSL, but not SAF. Both sub-lingual and inter-digital rear flipper venous catheters, as well as a left radial arterial catheter, were placed in SAF. Standard physiologic monitoring was performed, with the addition of direct arterial blood pressure in SAF. Crystalloid fluids differed between CSL and SAF (Normosol-R vs. 0.9% NaCl, respectively).
In both cases, hyperkalemia developed between 2.5 and 3 hours under anesthesia. Both responded to treatment with sodium bicarbonate and fluid therapy (0.9% NaCl). All pre-medications were reversed. Acute postoperative convalescence was uneventful, with both receiving dosages of carprofen. However, SAF became anorectic six days postoperatively. Renal insult was indicated (BUN 96 mg/dl; CR 10.9 mg/dl), carprofen suspended, fluid therapy instituted (12 L 0.9 % NaCl SQ daily), and urinalysis performed by catheterization.
The condition of SAF resolved seven days after detection. Retrospective analysis revealed elevated AST, LDH and CK in both cases implicating the spectrum illness - rhabdomyolysis - despite inability to document myoglobinuria.1-3,7,8 Monitoring blood pressure, positioning, padding and procedure duration are integral to peri-anesthetic myopathy prevention.4-6,9
Acknowledgements
The authors would like to thank the trainers, veterinary technicians, and veterinarians of the National Marine Mammal Foundation, Navy Marine Mammal Program and Mundo Aquático- Zoomarine Portugal. Special thanks go to those who have contributed to these cases, including Sam Ridgway of the National Marine Mammal Foundation, Mike Walsh of the Aquatic Animal Health Program of the University of Florida and Bruce Heath of Seven Seven Anesthesia Consulting.
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