Abstract:
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 m /kg) or morphine (AM-group; 0.1 mg/kg
diluted in saline to 0.2m /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 betweenAMand
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) andMAP.Within the AM-group
differences were statistically significant (P < 0.05) for DIA and MAP, 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.
