Nalbufina, butorfanol e morfina no controle da dor pós-operatória imediata em cadelas submetidas a ovariohisterectomia eletiva

Abstract

The management of perioperative pain can be performed by opioids, drugs that form the base of a balanced analgesic plane. The aim of this study was to compare the analgesic efficacy of nalbuphine, butorphanol and morphine in the early postoperative analgesia, in bitches submitted to ovariohysterectomy. Forty-eight healthy bitches of different breeds were randomly assigned to four treatments: nalbuphine 0,5 mg kg-1 (N0.5) and 1,0 mg kg-1(N1.0), butorphanol 0,4 mg kg-1(B0.4) or morphine 0,2 mg kg-1 (M0.2), combined with acepromazine 0,02 mg kg-1intravenously. Anesthesia was induced with propofol and maintained with isoflurane. Dynamic Interactive Visual Analog Scale (DIVAS, 0–100 mm), phases I (DIVAS I), II (DIVAS II) and III (DIVAS III), and the Modified Glasgow Composite Measure Pain Scale (GCMPS, 0–10) were used to used to assess pain prior administration of the drugs (BL), 1, 2, 3, 4, 5 and 6 hours after extubation. The analgesic rescue (0,2 mg kg1IV of morphine combined with 0,2 mg kg-1IV of meloxicam) was given if the dog had DIVAS > 70 mm or GCMPS > 3,5. B0.4 had a higher DIVAS II score compared with N1.0, at 2 (p = 0,038) and 3 hours (p = 0,002), and with N0.5 at 3 hours (p = 0,003). There was no difference in DIVAS I, III and GCMPS scores between treatments. Rescue analgesia was required in thirty-four bitches. The number of analgesic rescues (p = 0,813) and total dose of morphine given as rescue (p = 0,763) were not different between groups. Preemptive administration of nalbuphine, butorphanol and morphine produce similar postoperative analgesia with great possibility of analgesic rescue in the first 6 hours, therefore, over this period, regular and interactive evaluations should be performed to ensure adequate analgesia in bitches submitted to ovariohysterectomy.