Cardiovascular effects of epidural morphine or ropivacaine in isoflurane-anaesthetised pigs during surgical devascularisation of the liver.
The cardiovascular effects of non-abdominal and abdominal surgery during isoflurane anaesthesia (A-group) or isoflurane anaesthesia supplemented with either epidural ropivacaine (AR-group; 0.75 % solution, 0.2 ml/kg) or morphine (AM-group; 0.1 mg/kg diluted in saline to 0.2 ml/kg) were evaluated in 28 healthy pigs with a mean body weight of 30.3 kg SD +/- 4.1 during surgical devascularisation of the liver. Anaesthesia was induced with the intramuscular injection of midazolam (0.3 mg/kg) and ketamine (10 mg/kg). Anaesthesia was deepened with intravenous propofol to enable tracheal intubation and maintained with isoflurane on a circle rebreathing circuit. The vaporiser was set at 2.5% for the A-group and 1.5% for the AR- and AM-groups. Differences between treatment groups were not statistically significant (P > 0.05) for any of the variables. Differences between AM- and AR-groups were marginally significant heart rate (HR) (P = 0.06) and mean arterial blood pressure (MAP) (P = 0.08). Within treatment groups, differences for the A-group were statistically significant (P < 0.05) between non-abdominal and abdominal surgery for HR, systolic blood pressure, diastolic blood pressure (DIA) and MAP. Within the AM-group differences were statistically significant (P < 0.05) for DIA and MAE and within the AR group differences for all variables were not statistically significant (P > 0.05). It was concluded that in isoflurane-anaesthetised pigs, the epidural administration of ropivacaine decreased heart rate and improved arterial blood pressure during surgery.
Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110 South Africa. frik.stegmann@up.ac.za
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Stegmann
D000577:Amides / Q000008:administration & dosage; D000758:Anesthesia / Q000379:methods / Q000662:veterinary*; D000777:Anesthetics / Q000494:pharmacology*; D018685:Anesthetics, Inhalation; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007268:Injections, Epidural; D007530:Isoflurane; D008099:Liver / Q000098:blood supply / Q000601:surgery*; D009020:Morphine / Q000008:administration & dosage; D000077212:Ropivacaine; D013552:Swine / Q000502:physiology* / Q000601:surgery
D000577:Amides; D000777:Anesthetics; D018685:Anesthetics, Inhalation; D009020:Morphine; D000077212:Ropivacaine; D007530:Isoflurane