The effect of four anesthetic protocols on splenic size in dogs.

OBJECTIVE: To characterize the effects of four anesthetic protocols on the size of the spleen during surgery in dogs. STUDY DESIGN: Prospective experimental trial. ANIMALS: Twenty-four beagle dogs, 1.1 +/- 0.3 years of age and weighing 10.9 +/- 2.7 kg. METHODS: Dogs were allocated to receive one of four anesthetic protocols: 1 - pre-medication with acepromazine and butorphanol, induction with thiopental; 2 - pre-medication with acepromazine and butorphanol, induction with propofol; 3 - pre-medication with medetomidine and butorphanol, induction with propofol; and 4 - pre-medication with medetomidine and butorphanol, induction with ketamine and diazepam. Anesthesia was then maintained with halothane. At laparotomy, the spleen length, width, and height were measured, these were measured again just prior to closure of the abdomen. Splenic area and volume were calculated. Hematocrit and total serum protein (TSP) were measured before and after induction and during laparotomy. RESULTS: Splenic volume was greatest after protocol 4 (161.2 +/- 40.2 cm(3); p < 0.05) and was least after protocol 2. The differences in volume were because of differences in length, width, and height between groups. There was no significant change in area, length, or width over the study period. Hematocrit decreased significantly in all dogs but at different times. The decrease occurred after pre-medication if acepromazine was administered, at induction following protocol 3 and during surgery following protocol 4. CONCLUSIONS: If splenic volume is to be minimized during surgery, then acepromazine and propofol should be used in the anesthetic protocol. The administration of medetomidine, diazepam, and ketamine will produce a greater splenic volume. Lack of correlation between hematocrit and spleen size following the anesthetic protocols studied suggests sequestration of red blood cells in nonsplenic sites.

Evaluation of intraperitoneal and incisional lidocaine or bupivacaine for analgesia following ovariohysterectomy in the dog.

OBJECTIVE: To determine if intraperitoneal (i.p.) and incisional (s.c.) lidocaine or bupivacaine provide analgesia following ovariohysterectomy (OHE). STUDY DESIGN: Prospective, randomized, controlled, blinded clinical trial. ANIMALS: Thirty dogs presenting to the Veterinary Teaching Hospital for elective OHE. METHODS: Dogs were pre-medicated with acepromazine and butorphanol, induced with thiopental and maintained with isoflurane. They were randomly assigned to three groups: 10 received 8.8 mg kg(-1) 2% lidocaine with epinephrine i.p. (LID); 10 received 4.4 mg kg(-1) 0.75% bupivacaine i.p. (BUP); and 10 received 0.9% saline i.p. (SAL) upon completion of OHE. All i.p. doses were standardized to 0.88 mL kg(-1) with saline. An additional 2 mL of undiluted solution was placed s.c. prior to incisional closure. Dogs were scored at 0.5, 1, 2, 3, 6, 8 and 18 hours post-extubation by one observer. Dogs were evaluated using a visual analogue scale (VAS) for pain and sedation, and a composite pain scale (CPS) that included physiologic and behavioral variables. Dogs were treated with 0.22 mg kg(-1) butorphanol + acepromazine if their VAS (pain) score was >50. Parametric variables were analyzed using Student's t-test or repeated measures ANOVA as appropriate. Non-parametric variables were analyzed by chi2-test. RESULTS: There were no significant differences in age, weight, incision length, surgery time, anesthesia time, or total thiopental dose among groups. Peak post-surgical pain scores for all groups occurred at 0.5 hours and returned to baseline by 18 hours. Dogs in the BUP group had significantly lower VAS-pain scores overall than dogs in the SAL group. Seven out of 10 dogs in the SAL group, 4/10 in the LID group and 2/10 in the BUP group were treated with supplemental acepromazine and butorphanol. No differences between groups were detected with the CPS. No adverse side-effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE: Our findings support the use of i.p. and s.c. bupivacaine for post-operative analgesia following OHE in the dog.