Efficacy of Intrathecal Lidocaine, Bupivacaine, and Morphine for Spinal Anesthesia and Analgesia in Red-Eared Slider Turtles (Trachemys scripta elegans)
Abstract
Intrathecal or spinal anesthesia and analgesia have not been systematically evaluated in reptiles but the clinical application has been published.3 Possible benefits of this technique include shorter post-surgical recoveries and improved analgesia, particularly in chelonians undergoing surgical procedures of the cloaca or hind limbs.1-3 The aim of this study was to investigate the feasibility and efficacy of spinal anesthesia and analgesia in sedated, male, red-eared slider turtles (Trachemys scripta elegans) (body weight, 0.49–0.78 kg). Intrathecal injections were performed at the level of the mid- to proximal-coccygeal vertebrae using 0.5 ml insulin syringes with a 28 G x 1/2” needle (Tyco Healthcare Group LP, Mansfield, MA, USA). Using preservative-free lidocaine (4 mg/kg, 2%) or bupivacaine (1 mg/kg, 0.5%), complete motor block of the cloacal sphincter, tail, and hindlimbs was induced in 60% of all turtles after the initial injection attempt, and in 90% after one repeated injection, 15 minutes after the initial injection if unsuccessful. Mean duration of motor block of the hindlimbs was 67±24 minutes after lidocaine injection, and 121±57 minutes after bupivacaine injection. Intrathecal morphine (0.1–0.2 mg/kg, 4 mg/ml) resulted in thermal antinociception of the hindlimbs for up to 48 hours. These results indicate that intrathecal drug administration is a feasible and effective technique for induction of intrathecal anesthesia and analgesia in male red-eared slider turtles. Further research is warranted to evaluate the safety of intrathecal drug delivery, as well as feasibility of intrathecal anesthesia and analgesia in various chelonian species.
Literature Cited
1. Casati A, Vinciguerra F. Intrathecal anesthesia. Curr Opin Anaesthesiol. 2002;15:543–551.
2. Di Cianni S, Rossi M, Casati A, Cocco C, Fanelli G. Spinal anesthesia: an evergreen technique. Acta Biomed. 2008;79:9–17.
3. Rivera S, Divers SJ, Knafo SE, Martinez P, Cayot LJ, Tapia-Aguilera W, Flanagan J. Sterilization of hybrid Galapagos tortoises (Geochelone nigra) for island restoration. Part 2: phallectomy of males under intrathecal anaesthesia with lidocaine. Vet Rec. 2011;168:78–82.