Abstract
Objective
To determine the dose and cardiopulmonary effects of propofol alone or with midazolam
for induction of anesthesia in American Society of Anesthesiologists status ≥III dogs
requiring emergency abdominal surgery.
Study design
Prospective, randomized, blinded, clinical trial.
Animals
A total of 19 client-owned dogs.
Methods
Dogs were sedated with fentanyl (2 μg kg–1) intravenously (IV) for instrumentation for measurement of heart rate, arterial blood
pressure, cardiac index, systemic vascular resistance index, arterial blood gases,
respiratory rate and rectal temperature. After additional IV fentanyl (3 μg kg–1), the quality of sedation was scored and cardiopulmonary variables recorded. Induction
of anesthesia was with IV propofol (1 mg kg–1) and saline (0.06 mL kg–1; group PS; nine dogs) or midazolam (0.3 mg kg–1; group PM; 10 dogs), with additional propofol (0.25 mg kg–1) IV every 6 seconds until endotracheal intubation. Induction/intubation quality was
scored, and anesthesia was maintained with isoflurane. Variables were recorded for
5 minutes with the dog in lateral recumbency, breathing spontaneously, and then in
dorsal recumbency with mechanical ventilation for the next 15 minutes. A general linear
mixed model was used with post hoc analysis for multiple comparisons between groups (p < 0.05).
Results
There were no differences in group demographics, temperature and cardiopulmonary variables
between groups or within groups before or after induction. The propofol doses for
induction of anesthesia were significantly different between groups, 1.9 ± 0.5 and
1.1 ± 0.5 mg kg–1 for groups PS and PM, respectively, and the induction/intubation score was significantly
better for group PM.
Conclusions and clinical relevance
Midazolam co-induction reduced the propofol induction dose and improved the quality
of induction in critically ill dogs without an improvement in cardiopulmonary variables,
when compared with a higher dose of propofol alone.
Keywords
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Article info
Publication history
Published online: April 11, 2020
Accepted:
March 31,
2020
Received:
December 3,
2019
Identification
Copyright
Crown Copyright © 2020 Published by Elsevier Ltd on behalf of Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. All rights reserved.
