Abstract

Neuromuscular blocking agents (NMBAs) and their reversals are routinely used in veterinary ophthalmic surgery to provide muscle relaxation and facilitate surgical access. A newer NMBA reversal agent, sugammadex, offers faster, more effective, and more reliable reversal of NMBAs in humans and has demonstrated promise in veterinary species. This case series describes the use of the NMBA rocuronium and its reversal with sugammadex for lensectomy in pinnipeds. Eight pinnipeds (7 males, 1 female) from four participating institutions were anesthetized for unilateral or bilateral lensectomy (1 Otaria flavescens, 4 Zalophus californianus, 1 Pagophilus groenlandicus, 2 Phoca vitulina). Premedication was achieved with intramuscular administration of sedative drugs (butorphanol or meperidine with or without midazolam and alfaxalone) followed by induction using sevoflurane via facemask or intravenous propofol. Anesthesia was maintained with sevoflurane delivered via endotracheal tube, and animals were mechanically ventilated. Neuromuscular blockade was achieved with intravenous rocuronium (0.11±0.025 mg/kg), and 3/8 animals required an additional dose (0.07±0.04 mg/kg) 77+17 minutes later, prior to lensectomy of the contralateral eye. Intravenous sugammadex (1.9±0.22 mg/kg) was administered for rocuronium reversal following surgical procedure; two animals received an additional dose (2 mg/kg). All animals recovered uneventfully and without evidence of recurarization. In all animals, rocuronium provided sufficient surgical visualization and was adequately reversed with sugammadex, with no clinically apparent side effects. The combination of rocuronium and sugammadex should be considered in pinniped species and prompts further investigation of use in other marine mammals.

Acknowledgements

The authors thank the trainers, veterinary technicians, and veterinarians of the U.S. Navy Marine Mammal Program, Mundo Aquático S.A.—Zoomarine Portugal, Oklahoma City Zoo, SeaWorld Orlando, and Dolphin Adventure.

*Presenting author