Hysiological and hemato-biochemical effects of total intravenous administration of ketamine, propofol and their combinations in mixed-breed dogs
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Date
2024
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Publisher
Sokoine University of Agriculture
Abstract
There is increasing interest towards Total Intravenous Anaesthesia
(TIVA) among veterinarians. However, information on its application in
mixed breed dogs is limited. Data on the effects of ketamine, propofol
and their combination ‘ketofol’ administered through TIVA in mixed breed
dogs is also insufficient. This study assessed some of the physiological,
hematological and biochemical effects of induction and maintenance of
anaesthesia using ketamine and propofol individually, but also as a
combination in mixed-breed dogs. Ten healthy adult mixed-breed dogs
were divided into five treatment groups in a repeated crossover
experiment. Treatments provided were ketamine (KK), propofol (PP) and
ketamine + propofol (ketofol) at 1:1 (KP1), 1:2 (KP2) and 1:3 (KP3)
ratios. The dogs were premedicated with atropine (0.04 mg/kg IM) and
xylazine (2 mg/kg IM). Anaesthetic induction was through intravenous
administration of 5 mg/kg body weight in KK or PP; and 4 mg/kg
bodyweight ketofol i.e. 2 mg ketamine + 2 mg propofol in KP1; 1.3 mg
ketamine + 2.6 mg propofol in KP2 and 1 mg ketamine + 3 mg propofol in
KP3. Maintenance was by constant rate infusion (CRI) of 0.3 mg/kg/min
for 60 minutes in all the five groups. In the ketofol groups, the
maintenance protocol was 0.15 mg/kg/min ketamine + 0.15 mg/kg/min
propofol in KP1, 0.1 mg/kg/min ketamine + 0.2 mg/kg/min propofol in
KP2 and 0.075 mg/kg/min ketamine + 0.225 mg/kg/min propofol in KP3.
Physiological parameters assessed were rectal temperature, respiration
rate, pulse rate and oxygen saturation. Induction and recovery time and
quality were also determined, and side effects observed. Hematological
assessment included absolute White Blood Cell (WBC) counts;
differential lymphocyte, neutrophil and monocyte counts together with
total Red Blood Cells (RBC), hematocrit (HCT) and hemoglobin
concentration (HB). Serum biochemical assessment included Alanine
Aminotransferase (ALT), Aspartate Transaminase (AST), Blood Urea
Nitrogen (BUN) and Creatinine levels. Means were compared between KP3 group had a significant decrease in the RBC count (p=0.006) and
hemoglobin concentration (p=0.049) at the 60th minute. The decrease in
the remaining groups was statistically not significant. Differences in the
mean ALT level were significant among groups (p=0.047); KP2 had the
highest mean (10.74 ± 0.24 U/L), while KP1 had the lowest (5.71 ± 0.00
U/L). Within protocols, there was a significant decrease in the PP group
at the 30th minute (P<0.001). Changes in the other groups were not
significant. Differences in the AST were also significant among groups
(p=0.012). PP has the least mean concentration (6.06 ± 1.98 U/L), while
KP2 had the highest (12.22 ± 3.1 U/L). KP2 had a significant decrease at
the 60th minute (p<0.001). Changes in the other groups were not
significant. Non significant differences were also noted in the creatinine
and BUN concentration among groups, however there was a significant
decrease in creatinine in KP2 from the 30 th to 60th minute (p<0.001), and
a significant increase in BUN in the PP and KP3 groups at the 60th
minute (p<0.001). In general; ketamine, propofol and the 1:1, 1:2 and 1:3
Ketamine: Propofol combination ratios can safely be used in mixed breed
dogs. However due to low respiration rates and oxygen saturation,
coupled with decrease in red blood cell counts, hematocrit and
hemoglobin concentration observed in all the protocols; it is imperative to
diligently monitor the animals while under anaesthesia, but also ensure a
patent airway. In addition, under the conditions of this study, the 1:3
Ketamine:Propofol combination (KP3) resulted in relatively more stable
and predictable physiological effects with less side effects in comparison
to the 1:1 and 1:2 ratios. Further studies with increased sample sizes and
longer monitoring periods would provide additional knowledge on the
short- and long-term effects of these drugs and their combinations
administered through TIVA in mixed breed dogs.
Description
Disssertation
Keywords
Dog, Ketamine, Propofol, Total Intravenous Anaesthesia (TIVA)