Comparison of intraperitoneal ropivacaine and bupivacaine for postoperative analgesia in dogs undergoing ovariohysterectomy.

OBJECTIVE: To compare postoperative analgesia following either intraperitoneal (IP) ropivacaine or bupivacaine in dogs undergoing ovariohysterectomy (OVH) in the scope of multimodal analgesia. STUDY DESIGN: Prospective, randomized, blinded clinical study. ANIMALS: A total of 45 privately owned dogs undergoing OVH, aged 37 ± 28 months and weighing 11.3 ± 4.5 kg. METHODS: Dogs were premedicated with acepromazine (0.05 mg kg-1) and morphine (0.5 mg kg-1) intramuscularly (IM). Anaesthesia was induced with alfaxalone and maintained with isoflurane in oxygen. Carprofen (4 mg kg-1) was injected subcutaneously after intubation. Dogs were randomly assigned to receive either bupivacaine (group B; 3 mg kg-1) or ropivacaine (group R; 3 mg kg-1) IP prior to complete closure of the linea alba. At 0.5, 1, 2, 4, 6 and 8 hours after extubation, sedation and postoperative pain were assessed, using the short form of the Glasgow Composite Pain scale (GCPS-SF), a dynamic interactive visual analogue scale (DIVAS), and mechanical nociceptive threshold (MNT) measurement. Rescue morphine (0.2 mg kg-1) was administered in case of ≥ 5/20 or ≥ 6/24 in the GCPS-SF and/or >40 mm in the DIVAS. Parametric data were compared using the t test; nonparametric data were analysed with the two-sample Wilcoxon test (p < 0.05). RESULTS: The GCPS-SF score was significantly higher in group R at 8 hours. There was no other significant difference regarding sedation or analgesia between the groups. Rescue analgesia was administered to 15 dogs (R: 9/22; B: 6/22), with no significant difference between the groups. MNT values decreased in both groups at all time points when compared to baseline. No adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE: Ropivacaine or bupivacaine IP in combination with morphine IM and carprofen SC provided comparable postoperative analgesia in dogs after OVH for 6 hours. However, the anaesthetic protocol used did not prevent the administration of rescue analgesia in 41% of animals.

Intraperitoneal bupivacaine with or without incisional bupivacaine for postoperative analgesia in dogs undergoing ovariohysterectomy.

OBJECTIVE: Intraperitoneal (IP) bupivacaine provides postoperative analgesia in dogs undergoing ovariohysterectomy (OHE) alone or in combination with incisional (INC) bupivacaine. This study investigated whether the combination of INC and IP bupivacaine is superior to IP bupivacaine alone. STUDY DESIGN: Prospective, randomized, blinded clinical study. ANIMALS: Thirty-nine privately owned dogs undergoing OHE, aged 25 ± 23 months and weighing 11.8 ± 5.7 kg. METHODS: Dogs were premedicated with acepromazine (0.05 mg kg(-1) ) and morphine (0.5 mg kg(-1) ) intramuscularly (IM); anaesthesia was induced with propofol and maintained with isoflurane in oxygen. Carprofen (4 mg kg(-1) ) was administered subcutaneously (SC) after intubation. Bupivacaine (3 mg kg(-1) ) IP was administered before complete closure of the linea alba to all dogs. Dogs were randomly assigned into two groups: group B received bupivacaine (n = 20; 1 mg kg(-1) ) and group S received saline (n = 19; 0.2 mL kg(-1) ) INC as a subcutaneous 'splash' before skin closure. Postoperative analgesia was assessed with a dynamic interactive visual analogue scale, the short form of the Glasgow Composite Pain Scale, and mechanical nociceptive threshold (MNT) measurement at 0.5, 1, 2, 4, 6, 8, 12 and 20 hours after surgery by one blinded observer. Parametric data were tested using t-test; nonparametric data were analysed using the two-sample Wilcoxon test (p < 0.05). RESULTS: There was no significant difference between groups with regard to age, weight, surgical and anaesthetic duration, incision length, sedation and pain scores. MNT values decreased in both groups at all time points as compared with the baseline. No dog required rescue analgesia. No postoperative complications were observed. CONCLUSION AND CLINICAL RELEVANCE: Bupivacaine IP and carprofen SC after morphine IM did provide satisfactory postoperative analgesia in dogs undergoing OHE with the anaesthetic protocol used. There appears to be no clinical advantage to adding bupivacaine INC. Neither protocol could prevent the development of primary hyperalgesia.

Alfaxalone or ketamine-medetomidine in cats undergoing ovariohysterectomy: a comparison of intra-operative parameters and post-operative pain.

OBJECTIVE: To compare post-operative pain in cats after alfaxalone or ketamine- medetomidine anaesthesia for ovariohysterectomy (OHE) and physiologic parameters during and after surgery. STUDY DESIGN: Prospective 'blinded' randomized clinical study. ANIMALS: Twenty-one healthy cats. METHODS: Cats were assigned randomly into two groups: Group A, anaesthesia was induced and maintained with alfaxalone [5 mg kg(-1) intravenously (IV) followed by boli (2 mg kg(-1) IV); Group MK, induction with ketamine (5 mg kg(-1) IV) after medetomidine (30 µg kg(-1) intramuscularly (IM)], and maintenance with ketamine (2 mg kg(-1) IV). Meloxicam (0.2 mg kg(-1) IV) was administered after surgery. Basic physiological data were collected. At time T = -2, 0, 0.5, 1, 2, 4, 6, 8, 12, 16, 20, and 24 hours post-operatively pain was assessed by three methods, a composite pain scale (CPS; 0-24 points), a visual analogue scale (VAS 0-100 mm), and a mechanical wound threshold (MWT) device. Butorphanol (0.2 mg kg(-1) IM) was administered if CPS was scored ≥13. Data were analyzed using a general linear model, Kruskal-Wallis analyses, Bonferroni-Dunn test, unpaired t-test and Fisher's exact test as relevant. Significance was set at p < 0.05. RESULTS: VASs were significantly higher at 0.5, 1, 2, 4, and 20 hours in group A; MWT values were significantly higher at 8 and 12 hours in group MK. Post-operative MWT decreased significantly compared to baseline in both groups. There was no difference in CPS at any time point. Five cats required rescue analgesia (four in A; one in MK). CONCLUSION AND CLINICAL RELEVANCE: Anaesthesia with ketamine-medetomidine was found to provide better post-surgical analgesia than alfaxalone in cats undergoing OHE; however, primary hyperalgesia developed in both groups. Alfaxalone is suitable for induction and maintenance of anaesthesia in cats undergoing OHE, but administration of additional sedative and analgesic drugs is highly recommended.