Evaluation of lidocaine administration into the ovarian pedicle for the control of intraoperative and early postoperative pain during ovariohysterectomy in dogs.

OBJECTIVE: To evaluate effects of lidocaine 2% administration into the ovarian pedicle on intraoperative nociception and early postoperative pain in dogs undergoing ovariohysterectomy. STUDY DESIGN: Prospective, randomized, blinded clinical study. ANIMALS: A total of 20 healthy adult female dogs of different breeds. METHODS: Dogs were premedicated with acepromazine (0.02 mg kg-1) and morphine (0.5 mg kg-1) intramuscularly, anesthesia induced with propofol and maintained with isoflurane. Dogs were randomly assigned to be administered 2 mL of saline (group S) or lidocaine 2% (group L) into the mesovarium (1 mL each side). Heart rate (HR) and noninvasive systemic arterial pressure were recorded before surgery (T0), before (T1) and during ligation of the right ovarian pedicle (T2), before (T3) and during ligation of the left ovarian pedicle (T4). Rescue treatment (propofol) was administered if HR or systolic arterial pressure (SAP) increased by 20% compared with the previous time point. Pain, assessed with the Glasgow Composite Measure Pain Scale-Short Form (CMPS-SF) was recorded before premedication (baseline) and after extubation. Administration of postoperative rescue analgesia was recorded. RESULTS: In group S, HR was higher at T2 than T1 (112 ± 18 versus 89 ± 21 beats minute-1, p = 0.001) There were no significant differences between treatments at any time. SAP was higher at T2 than T1 in group S (110 ± 12 versus 100 ± 10 mmHg, p = 0.031). SAP was higher in group S than group L at T3 (113 ± 12 and 91 ± 10 mmHg, respectively, p = 0.001). No dogs required propofol intraoperatively. All dogs required postoperative rescue analgesia. Compared with baseline, CMPS-SF increased 60 minutes after extubation (group S; p = 0.019, group L; p = 0.043). CONCLUSIONS AND CLINICAL RELEVANCE: Administration of lidocaine 2% into the mesovarium did not reduce intraoperative nociception and did not improve postoperative analgesia.

Ketamine-dexmedetomidine combined with local anesthesia, with or without different doses of atipamezole in the postoperative period, for orchiectomy in cats.

OBJECTIVE: To evaluate the anesthetic and cardiopulmonary effects of ketamine-dexmedetomidine combined with local anesthesia, associated or not in the postoperative period with different doses of atipamezole, for orchiectomy in cats. ANIMALS: 24 healthy cats. PROCEDURES: Cats received ketamine (7 mg/kg) combined with dexmedetomidine (10 µg/kg) IM, and 1 mL of saline (group KDSAL), 25 µg/kg (group KDAT25), or 50 µg/kg (group KDAT50) of atipamezole IV, postoperatively. All cats received local anesthesia (2 mg/kg of lidocaine) intratesticular and SC. Physiologic variables were recorded at baseline and at time points during anesthesia. Ketamine rescue dose (1 mg/kg) was recorded. The quality of recovery, the degree of sedation, and side effects were evaluated postoperatively. RESULTS: 2 cats received a single additional bolus of ketamine to perform local anesthesia. Heart rate was lower in KDSAL, KDAT25, and KDAT50 during anesthesia, compared with baseline. Hypertension was observed intraoperatively in all groups. The time to head up, pedal reflex regained time, time to sternal recumbency, and time to standing were shorter in KDAT25 and KDAT50 compared to KDSAL. Lower sedation scores were assigned sooner to KDAT25 and KDAT50 than KDSAL. All groups resulted in low recovery quality scores and no side effects. CLINICAL RELEVANCE: At the doses used, ketamine-dexmedetomidine combined with local anesthesia allowed the performance of orchiectomy. Rescue dose of ketamine for performing local anesthesia may be required. This combination can result in hypertension. Both atipamezole doses shortened the anesthetic recovery, without differences among them, and side effects.

Effects of dissociative anesthesia opioid-free protocols combined with local anesthesia, with or without flumazenil or atipamezole postoperatively, for orchiectomy in cats.

OBJECTIVE: To evaluate the anesthetic effects of two drug combinations with local anesthesia, with or without postoperative antagonists, for orchiectomy in cats. STUDY DESIGN: Prospective, randomized blinded clinical study. ANIMALS: A total of 64 healthy cats. METHODS: Cats were assigned to four equal groups: ketamine (5 mg kg-1) and dexmedetomidine (10 µg kg-1) were administered intramuscularly (IM), followed postoperatively with intravenous (IV) saline (5 mL; group KDS) or atipamezole (50 µg kg-1; group KDA); and ketamine (14 mg kg-1) with midazolam (0.5 mg kg-1) and acepromazine (0.1 mg kg-1) IM, with postoperative IV saline (5 mL; group KMAS) or flumazenil (0.1 mg kg-1; group KMAF). Lidocaine (2 mg kg-1) was divided between subcutaneous and intratesticular injection. Physiologic variables were recorded at time points during anesthesia. Ketamine rescue dose was recorded. The degree of sedation and the quality of recovery were evaluated postoperatively. RESULTS: Time to loss of pedal reflex was longer in groups KMAS and KMAF than in groups KDS and KDA (p = 0.010). Total rescue dose of ketamine was higher in KMAS and KMAF than in KDS and KDA (p = 0.003). Heart rate (HR) during anesthesia was higher in KMAS and KMAF than in KDS and KDA (p = 0.001). Times to head up (p = 0.0005) and to sternal recumbency (p = 0.0003) were shorter in KDA than in KDS, KMAS and KMAF. Lower sedation scores were assigned sooner to KDA than KDS, KMAS and KMAF (p < 0.001). Recovery quality scores were good in all groups. CONCLUSIONS AND CLINICAL RELEVANCE: Both anesthetic protocols allowed the performance of orchiectomy. Groups KMAS and KMAF required higher rescue doses of ketamine before injecting lidocaine. HR and oscillometric systolic pressure were minimally changed in groups KD and tachycardia was recorded in groups KMA. Only atipamezole shortened the anesthetic recovery.

Evaluation of nalbuphine, butorphanol and morphine in dogs during ovariohysterectomy and on early postoperative pain.

OBJECTIVE: To evaluate the effects of nalbuphine, butorphanol and morphine combined with acepromazine on intraoperative and early postoperative pain management in dogs anesthetized for ovariohysterectomy. STUDY DESIGN: Prospective, randomized blinded clinical study. ANIMALS: A total of 48 healthy female dogs of different breeds, aged 1-6 years, weighing (mean ± standard deviation) 14.5 ± 4.8 kg. METHODS: Dogs were randomly assigned into four groups to be intravenously administered nalbuphine (0.5 mg kg-1; group N0.5), nalbuphine (1.0 mg kg-1; group N1.0), butorphanol (0.4 mg kg-1; group B0.4) or morphine (0.2 mg kg-1; group M0.2) combined with acepromazine (0.02 mg kg-1) prior to propofol and isoflurane for anesthesia. Heart rate (HR), respiratory rate, systolic arterial pressure and rectal temperature (RT) were recorded at time points during anesthesia. A dynamic interactive visual analog scale applied in three phases (DIVAS I, II and III) and the modified Glasgow composite measure pain scale were used to assess pain before premedication and 1, 2, 3, 4, 5 and 6 hours after extubation. Administration of rescue analgesia was recorded. RESULTS: At the left ovarian pedicle ligation, HR was higher in N1.0 than in B0.4 (p = 0.020). RT decreased significantly by the end of surgery in N0.5 (p = 0.043) and B0.4 (p = 0.010). Rescue analgesia was administered postoperatively over 6 hours to eight, seven, nine and 10 dogs in N0.5, N1.0, B0.4 and M0.2, respectively (p = 0.57). DIVAS II was higher in B0.4 than in N1.0 at 2 and 3 hours (p = 0.038 and p = 0.002, respectively) and N0.5 at 3 hours (p = 0.003). CONCLUSIONS AND CLINICAL RELEVANCE: At the doses used, all premedication protocols provided insufficient intraoperative analgesia, with minimal clinical differences between groups. No premedication provided satisfactory analgesia in the first 6 hours postoperatively.

Effect of three doses of nalbuphine on reversal of sedation and cardiopulmonary effects of morphine-acepromazine in healthy dogs.

OBJECTIVE: To evaluate the efficacy of three doses of nalbuphine in reversing sedative and cardiopulmonary effects of morphine-acepromazine in dogs. STUDY DESIGN: Prospective, randomized experimental trial. ANIMALS: A group of eight healthy Beagle dogs, aged 5-6 years and weighing 12.5 ± 2.1 kg. METHODS: Dogs were administered morphine (0.5 mg kg-1) and acepromazine (0.05 mg kg-1) intravenously (IV). After 20 minutes, dogs were administered one of four treatments IV: saline (control); or nalbuphine (0.3 mg kg-1; treatment N0.3), (0.6 mg kg-1; treatment N0.6) or (1.0 mg kg-1; treatment N1.0), in random order separated by 1 week. Sedation was scored using a numeric descriptive scale (NDS) and simple numerical scale (SNS). Heart rate, systolic arterial pressure (SAP), respiratory rate (fR) and rectal temperature (RT) were recorded before (BL), 20 minutes after morphine-acepromazine (T0), then 10 (T10), 30, 60 and 90 minutes after saline or nalbuphine. Arterial blood gases were measured at BL, T0 and T10. Values were compared with BL, T0 and among treatments using anova (p < 0.05) and the Bonferroni correction (p < 0.008). RESULTS: NDS for N0.6 and SNS for N0.6 and N1.0 at T30, and both scores for all nalbuphine treatments at T60-T90 were lower compared with T0 (p < 0.05). Sedation scores were not different among nalbuphine treatments. SNS scores were lower than control at T10 for N0.3 and N0.6 (p < 0.05). SAP and fR were lower than BL for all treatments at some time points (p < 0.05). RT was higher than control at T60 in the nalbuphine treatments (p < 0.001). PaO2 was lower in N0.3 at T0 compared with BL (p = 0.036). CONCLUSIONS AND CLINICAL RELEVANCE: All nalbuphine doses decreased the degree of sedation, without differences among them. Administration of nalbuphine resulted in minimal changes in measured cardiopulmonary variables.

Comparison of the sedative effects of nalbuphine and butorphanol, alone or in combination with acepromazine in dogs.

OBJECTIVE: To compare sedation and effects on heart rate (HR), mean arterial pressure (MAP) and respiratory rate (fR) of nalbuphine and butorphanol, alone or combined with acepromazine in dogs. STUDY DESIGN: Prospective, randomized experimental trial. ANIMALS: Eight healthy Beagle dogs, aged (mean ± standard deviation) 3.4 ± 0.5 years and weighing 11.0 ± 1.3 kg. METHODS: Each dog was treated four times: physiological saline (1 mL) combined with nalbuphine (0.5 mg kg-1; SAL-NAL) or butorphanol (0.15 mg kg-1; SAL-BUT), and acepromazine (0.05 mg kg-1) combined with nalbuphine (0.5 mg kg-1; ACP-NAL) or butorphanol (0.15 mg kg-1; ACP-BUT), intravenously (IV). The degree of sedation, assessed by a numeric descriptive scale (NDS) and simple numerical scale (SNS), HR, MAP, fR and rectal temperature (RT), were recorded before and 20 minutes after administration of saline or acepromazine, then 15, 30, 60, 90 and 120 minutes after nalbuphine or butorphanol. Values were compared with baseline and among treatments. RESULTS: Mild sedation was recorded for SAL-NAL and SAL-BUT, and moderate sedation for ACP-NAL and ACP-BUT. NDS and SNS scores were higher for SAL-BUT and ACP-BUT at some time points when compared with SAL-NAL and ACP-NAL, respectively (p < 0.001). HR was lower in ACP-NAL than in ACP-BUT at 120 minutes and fR was lower in SAL-BUT than in SAL-NAL at 30 and 120 minutes (p < 0.05). RT was lower in SAL-BUT (37.5 ± 0.5 °C) compared with SAL-NAL (38.0 ± 0.5 °C) at 60-120 minutes (p < 0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Butorphanol promoted a higher sedative effect than nalbuphine when alone and combined with acepromazine. IV administration of nalbuphine or butorphanol, with or without acepromazine, at the doses studied, resulted in minimal decreases in MAP, HR, fR and RT.