D. Correia et al., PHARMACOKINETICS OF PROPOFOL INFUSIONS, EITHER ALONE OR WITH KETAMINE, IN SHEEP PREMEDICATED WITH ACEPROMAZINE AND PAPAVERETUM, Research in Veterinary Science, 60(3), 1996, pp. 213-217
The pharmacokinetics of propofol were investigated in two groups of fi
ve Scottish blackface sheep undergoing surgery for the implantation of
subcutaneous tissue pouches. After premedication with acepromazine an
d papaveretum, anaesthesia was induced with either propofol at 4 mg kg
(-1) intravenously (group 1) or with a mixture of propofol at 3 mg kg(
-1) and ketamine at 1 mg kg(-1) intravenously (group 2). Anaesthesia w
as maintained with a variable infusion rate of either propofol alone (
group 1) or propofol and ketamine (group 2). Both regimens produced sa
tisfactory conditions for superficial surgery of the body surface. The
mean (SD) duration of anaesthesia was 64.8 (3.1) minutes for group 1
and 60 (0) minutes for group 2; the mean total dose of propofol given
to the sheep in group 1 was 801 (84) mg, and the sheep in group 2 rece
ived 470 (46) mg of propofol and 267 (30) mg of ketamine. The mean eli
mination half-life of propofol was 56.6 (13.1) minutes in group 1 and
50 3 (21.4) minutes in group 2; the mean volume of distribution at ste
ady state was 1.037 (0.480) litre kg(-1) in group 1 and 1.515 (0 939)
litre kg(-1) in group 2; the mean body clearance was 85.4 (28.0) ml kg
(-1) min(-1) in group 1 and 128.0 (35 0) ml kg(-1) min(-1) in group 2;
the mean residence time corrected for a bolus injection was 12.1 (4.2
) minutes in group 1 and 11.9 (6.6) minutes in group 2; for the infusi
on, the mean residence time was 72.1 (4.2) minutes in group 1 and 69.9
(7.9) minutes in group 2. There were wide variations in the blood pro
pofol concentrations reached in individual sheep by using this standar
d dosing regimen. All the sheep recovered quickly from anaesthesia; th
e mean times to extubation, sternal recumbency and standing for the an
imals in group 1 were 2.8 (0.4), 6.3 (1.2) and 10.9 (1.6) minutes from
the end of the infusion, and the times for group 2 were 5.3 (0.9), 11
.2 (1.7) and 15.1 (2.2) minutes.