Evaluation of risk factors, including fluconazole administration, for prolonged anesthetic recovery times in horses undergoing general anesthesia for ocular surgery: 81 cases (2006-2013).

OBJECTIVE--To determine risk factors for prolonged anesthetic recovery time in horses that underwent general anesthesia for ocular surgery. DESIGN--Retrospective cohort study. ANIMALS--81 horses that underwent general anesthesia for ocular surgery between 2006 and 2013. PROCEDURES--Descriptive information recorded included the ocular procedure performed, concurrent fluconazole treatments, analgesic and anesthetic agents administered, procedure duration, use of sedation for recovery, and recovery time. Data were analyzed for associations between recovery time and other variables. RESULTS--81 horses met inclusion criteria. In 72 horses, anesthesia was induced with ketamine and midazolam; 16 horses treated concurrently with fluconazole had significantly longer mean recovery time (109 minutes [95% confidence interval {CI}, 94 to 124 minutes]) than did 56 horses that were not treated with fluconazole (50 minutes [95% CI, 44 to 55 minutes]). In 9 horses anesthetized with a protocol that included ketamine but did not include midazolam, there was no difference between mean recovery time in horses that either received (59 minutes [95% CI, 36 to 81 minutes]; n = 5) or did not receive (42 minutes [95% CI, 16 to 68 minutes]; 4) fluconazole. Other variables identified as risk factors for prolonged recovery included duration of anesthesia and use of acepromazine for premedication. CONCLUSIONS AND CLINICAL RELEVANCE--Fluconazole administration was associated with prolonged anesthetic recovery time in horses when ketamine and midazolam were used to induce anesthesia for ocular surgery. Duration of anesthesia and premedication with acepromazine were also identified as risk factors for prolonged recovery time.

Ischemic postconditioning does not attenuate ischemia-reperfusion injury of rabbit small intestine.

OBJECTIVE: To determine whether ischemic postconditioning can attenuate intestinal ischemia-reperfusion (I-R) injury and has a beneficial effect on tissue blood flow during reperfusion. STUDY DESIGN: In vivo experimental study. ANIMALS: New Zealand White rabbits (n=6). METHODS: Rabbits were anesthetized with pentobarbital, to avoid the preconditioning effects of volatile anesthetics, and ventilated with room air. Rectal temperature, hemodynamics, and normocapnia were maintained. After celiotomy, 3 jejunal segments were isolated in each rabbit for the following groups: (1) control, (2) I-R, and (3) I-R with postconditioning. I-R was induced by a 45-minute occlusion of the segment jejunal artery followed by 2-hour reperfusion. The postconditioning segment had 4 cycles of 30-second reperfusion and 30-second reocclusion during the initial 4 minutes of reperfusion. Stable isotope-labeled microspheres were used to measure intestinal blood flow at baseline, end occlusion, and end reperfusion. At the end of reperfusion, intestine segments were harvested and the rabbits euthanatized. A semiquantitative histopathologic evaluation (0-5) was conducted by a single, blinded observer. Wet-to-dry weight ratios were calculated to assess intestinal edema. RESULTS: There was no significant difference in grade of necrosis, tissue wet-to-dry weight ratios, or blood flow at any time point between ischemic and postconditioning groups. CONCLUSIONS: Ischemic postconditioning was ineffective in this model of intestinal I-R. CLINICAL RELEVANCE: Further experimental studies will need to be performed before clinical application of postconditioning for intestinal ischemia.

A model for clinical evaluation of perioperative analgesia in rabbits (Oryctolagus cuniculus).

Assessment of pain in rabbits is challenging, and studies of effective surgical analgesia are lacking for this species. Seeking potential indicators of postoperative pain, we performed ovariohysterectomy and telemeter placement as a form of moderate surgical injury in 20 female rabbits. Rabbits were assigned to 1 of 4 treatment groups (5 per group): buprenorphine (0.02 mg/kg SC every 12 h for 3 d); fentanyl (25-µg patch placed 24 h preoperatively); ketoprofen (1 mg/kg SC every 24 h for 3 d), and control (no treatment given). Various physiologic and behavioral variables were recorded by blinded observers, including food and water consumption, fecal output, and remotely recorded behaviors during daily exercise in 1.2 × 1.8 m floor pens. Compared with preoperative values, significant declines occurred in: food consumption (days 1 to 7), water consumption (days 1 to 4), fecal output (days 1 to 2), mean travel distance, and rearing (days 1 to 3 and day 7). No single treatment proved significantly better than another. Our results demonstrate substantial inappetance and reduction of normal activity levels in rabbits after surgery. Although results from rabbits treated with empirical doses (those typically recommended) of analgesics did not appear substantially better than those from the untreated control group, comparison of other doses and multimodal analgesic techniques by using these behavioral monitoring strategies may prove useful in future studies aimed at optimizing postoperative analgesia in rabbits.

Use of wound soaker catheters for the administration of local anesthetic for post-operative analgesia: 56 cases.

OBJECTIVE: To describe the administration of local anesthetic through wound soaker catheters for post-operative veterinary patients and to characterize complications. STUDY DESIGN: Retrospective study of hospital records. ANIMALS: Records of patients in which a wound soaker catheter was placed post-operatively between November 1, 2004 and July 1, 2006 at a veterinary teaching hospital. Records in which a limb amputation was performed between January 1, 2002 and August 1, 2007 and in which a wound soaker catheter was not placed were reviewed for historic control. RESULTS: A total of 56 cases were identified in which a wound soaker catheter was placed post-operatively including 52 dogs, 2 cats, and 2 goats. Twenty canine cases were identified in which limb amputation was performed and no wound soaker catheter was placed. The majority of surgical procedures for which a wound soaker catheter was placed included thoracic limb amputation (46.4%) and pelvic limb amputation (35.7%). Wound soaker catheters remained in place for an average of 1.6 +/- 0.5 days. Feline and caprine patients received intermittent bupivacaine boluses every 6 hours. Canine patients received continuous lidocaine infusions. Complications included disconnection of the catheter from the infusion (7.7%), one seroma, and one suspected lidocaine neurotoxicity. Incisional infections were noted in 3/56 (5.3%) limb amputations with wound soaker catheters placed which was not higher than the incisional infection rate found in the historic control cases 3/20 (15%). CONCLUSION AND CLINICAL RELEVANCE: Use of the wound soaker catheter was a viable means of providing local analgesia in post-operative veterinary patients. Studies are needed to evaluate efficacy of pain management, and to further investigate techniques for catheter placement and maintenance which may help to optimize the analgesia achieved using this technique.