Use of lidocaine-bupivacaine-infused absorbable gelatin hemostatic sponges versus lidocaine-bupivacaine retrobulbar injections for postoperative analgesia following eye enucleation in dogs.

OBJECTIVE: To compare use of lidocaine-bupivacaine-infused absorbable gelatin hemostatic sponges versus lidocaine-bupivacaine retrobulbar injections for postoperative analgesia in dogs following eye enucleation. DESIGN: Randomized case-control study. ANIMALS: 19 dogs that underwent eye enucleation. PROCEDURES: 19 client-owned dogs admitted to a referral hospital for routine eye enucleation were enrolled with owner consent and randomly assigned to receive an orbital absorbable gelatin hemostatic sponge infused with lidocaine and bupivacaine after globe removal (n = 8) or retrobulbar injection of lidocaine and bupivacaine before globe removal (11). Baseline pain scores were recorded on the basis of an ordinal pain scale. Anesthetic premedication consisted of hydromorphone, midazolam, and glycopyrrolate. Propofol was used for anesthetic induction and isoflurane for maintenance. A transpalpebral eye enucleation was performed by a board-certified ophthalmologist. Pain scores and heart rate were again recorded 15 and 30 minutes and 1, 2, 4, 6, 8, and 24 hours after extubation by trained observers masked to treatment groups. Dogs were given hydromorphone as rescue analgesia if the total pain score was ≥ 9 of 18 or any categorical pain score was ≥ 3 (on a scale from 0 to 3 or 0 to 4). RESULTS: There were significant differences over time for comfort level, response to touch, behavior, heart rate, and total pain score; however, there was no difference between treatment groups. One dog in the absorbable gelatin hemostatic sponge group required rescue hydromorphone 4 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: The absorbable gelatin hemostatic sponge proved to be as effective in providing local analgesia for eye enucleation in dogs as the retrobulbar injections.

Pharmacokinetics of hydrocodone and hydromorphone after oral hydrocodone in healthy Greyhound dogs.

The purpose of this study was to determine the pharmacokinetics of hydrocodone and its active metabolite hydromorphone in six healthy Greyhound dogs. Hydrocodone bitartrate was administered at a targeted dose of 0.5 mg/kg PO. Plasma concentrations of hydrocodone and hydromorphone were determined by liquid chromatography triple quadrupole mass spectrometry. The mean hydrocodone CMAX was 11.73 ng/mL at 0.74 h with a terminal half-life of 1.60 h. The mean hydromorphone CMAX was 5.2 ng/mL at 1.37 h with a terminal half-life of 3.07 h. Mean plasma hydromorphone concentrations exceeded 2 ng/mL from 0.5 to 8 h after hydrocodone administration. Further studies assessing the antinociceptive effects of oral hydrocodone are needed.