Objective—To assess sedative and cardiopulmonary effects of premedication with a medetomidine-buprenorphine or acepromazine-buprenorphine combination in dogs anesthetized with propofol and isoflurane.
Design—Randomized controlled clinical trial.
Animals—90 dogs undergoing routine surgical and diagnostic procedures.
Procedures—Dogs were randomly assigned to 1 of 3 premedication groups: group 1 (acepromazine, 0.03 mg/kg [0.014 mg/lb], IM; buprenorphine, 0.02 mg/kg [0.009 mg/lb], IM), 2 (medetomidine, 5 μg/kg [2.3 μg/lb], IM; buprenorphine, 0.02 mg/kg, IM), or 3 (medetomidine, 10 μg/kg [4.5 μg/lb], IM; buprenorphine, 0.02 mg/kg, IM). Anesthesia was induced with propofol and maintained with isoflurane in oxygen. Simple descriptive scores for sedation were assigned 15 minutes (groups 2 and 3) and 30 minutes (group 1) after premedication administration. Basic cardiopulmonary data were recorded throughout the anesthetic period. Times to recovery from anesthesia were recorded.
Results—Sedation scores did not differ significantly among groups. Mean and diastolic blood pressures were significantly lower and heart rate was significantly higher in group 1 than in the other groups. Mean end-tidal partial pressure of CO2 was significantly lower and respiratory rate was significantly higher in group 1 than in the other groups. There were no significant differences in anesthetic recovery times between groups.
Conclusions and Clinical Relevance—Results suggested that either acepromazine or medetomidine could be used in combination with buprenorphine for premedication of dogs anesthetized with propofol and isoflurane for routine surgical and diagnostic procedures. Arterial blood pressure was better maintained with the medetomidine-buprenorphine combinations, but tissue perfusion was not investigated.
Objective—To compare the effects of preoperatively administered pentastarch (10% concentration in isotonic saline [0.9% NaCl] solution) and hypertonic saline (7.2% NaCl) solutions on PCV and circulating total protein (TP) concentration in horses with colic undergoing emergency exploratory laparotomy and to assess survival rates of horses that received each treatment.
Design—Prospective, randomized study.
Animals—100 horses with signs of abdominal pain and PCV ≥ 0.46 L/L.
Procedures—Horses received a 4 mL/kg (1.8 mL/lb) dose of pentastarch solution (n = 50) or hypertonic saline solution (50) over a 10- to 20-minute period before anesthetic induction. Blood samples were collected at the time of evaluation and ≤ 5 minutes after fluid resuscitation; changes in PCV and TP concentration were compared. Survival was evaluated by Kaplan-Meier and Cox proportional hazards analyses.
Results—Age, weight, sex, PCV, and heart rate on initial examination were similar between treatment groups. Hypertonic saline solution treatment resulted in a significantly greater reduction in PCV (median change, −0.14 L/L) than did pentastarch treatment (median change, −0.07 L/L). Reduction in TP concentration was also significantly greater after hypertonic saline solution treatment (median change, −16 g/L) than after pentastarch treatment (median change, −2 g/L). Long-term survival was not significantly different between groups.
Conclusions and Clinical Relevance—Despite a greater reduction in preanesthetic hemoconcentration following administration of hypertonic saline solution (4 mL/kg infusion, once), no difference in overall long-term survival was found between horses that received this treatment and those that received an equal volume of pentastarch solution. Findings suggested that, in a clinical setting, either of these fluids would be appropriate for preoperative fluid resuscitation in horses with colic.