Effect of three opioid-based analgesic protocols on the perioperative autonomic-mediated cardiovascular response in sheep. (October 2019)

• Record Type: Journal Article
• Authors: Bellini, Luca; De Benedictis, Giulia Maria
• Is Part Of: Laboratory animals. Volume 53:Number 5(2019)
• Page Start: 491
• Page End: 499
• Publication Date: 2019-10
• Subjects: sheep -- methadone -- fentanyl -- buprenorphine -- analgesia -- spinal surgery; Animal experimentation -- Periodicals; Animal models in research -- Periodicals; Laboratory animals -- Periodicals; Animal welfare -- Periodicals; 636.0885
• DOI: 10.1177/0023677218815203
• Languages: English
• ISSNs: 0023-6772

Abstract

Few reports evaluate the clinical effects of opioids in sheep during experimental surgical procedures. Catecholamine-mediated haemodynamic changes resulting from surgical noxious stimulation are blunted by opioids. The aim of this study was to evaluate the efficacy of three opioid-based analgesic protocols in avoiding a 20% increase in heart rate (HR) and/or mean arterial blood pressure (MAP) during experimental intervertebral disk nucleotomy in sheep. Eighteen female Brogna sheep were anaesthetized with propofol and maintained with a fixed end-tidal isoflurane concentration of 1.5 ± 0.1%. Sheep were assigned to one of three groups that intravenously received methadone 0.3 mg/kg (group M), fentanyl 2 µg/kg followed by 10 µg/kg/h (group F), or buprenorphine 10 µg/kg and 30 minutes later ketamine 1 mg/kg followed by 5 mg/kg/h (group BK). Intravenous fentanyl at 2 µg/kg would have been used for rescue analgesia in case HR and/or MAP had increased. During surgery, HR and MAP values did not increase over 20% in all groups. All animals maintained the percentage change between -4 and 7% for both variables; only one sheep in group BK had an increase in MAP superior to 20% after ketamine administration before surgical stimulation. In group M, HR decreased over time and in group BK, MAP tended to increase during surgery. All the opioid-based protocols tested were able to control the cardiovascular response to noxious stimulation in sheep undergoing spinal surgery, although ketamine may have represented a confounding factor.