Hemodynamic effects of epidural ketamine in isoflurane-anesthetized dogs.
OBJECTIVE
The purpose of this study was to determine the hemodynamic effects of epidural ketamine administered during isoflurane anesthesia in dogs.


METHODS
Prospective, single-dose trial.


METHODS
Six healthy dogs (five males, one female) weighing 25.3 +/- 3.88 kg.


METHODS
Once anesthesia was induced, dogs were maintained at 1.5 times the predetermined, individual minimum alveolar concentration (MAC) of isoflurane. Dogs were instrumented and allowed to stabilize for 30 minutes before baseline measurements were recorded. Injection of 2 mg/kg of ketamine in 1 mL saline/4.5 kg body weight was then performed at the lumbosacral epidural space. Hemodynamic data were recorded at 5, 10, 15, 20, 30, 45, 60, and 75 minutes after epidural ketamine injection. Statistical analysis included an analysis of variance (ANOVA) for repeated measures over time. All data were compared with baseline values. A P < .05 was considered significant.


RESULTS
Baseline values +/- standard error of the mean (X +/- SEM) for heart rate, mean arterial pressure, mean pulmonary artery pressure, central venous pressure, pulmonary capillary wedge pressure, cardiac index, stroke index, systemic vascular resistance, pulmonary vascular resistance, and rate-pressure product were 108 +/- 6 beats/min, 85 +/- 10 mm Hg, 10 +/- 2 mm Hg, 3 +/- 1 mm Hg, 5 +/- 2 mm Hg, 2.3 +/- 0.3 L/min/m2, 21.4 +/- 1.9 mL/beat/m2, 3386 +/- 350 dynes/sec/cm5, 240 +/- 37 dynes/sec/cm5, and 12376 +/- 1988 beats/min x mm Hg. No significant differences were detected from baseline values at any time after ketamine injection.


CONCLUSIONS
The epidural injection of 2 mg/kg of ketamine is associated with minimal hemodynamic effects during isoflurane anesthesia.


CONCLUSIONS
These results suggest that if epidural ketamine is used for analgesia in dogs, it will induce minimal changes in cardiovascular function.
Martin
D D
DD
Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, USA.
Tranquilli
W J
WJ
Olson
W A
WA
Thurmon
J C
JC
Benson
G J
GJ
D000767:Anesthesia, Epidural / Q000662:veterinary*; D000769:Anesthesia, Inhalation / Q000662:veterinary; D019162:Anesthetics, Combined / Q000008:administration & dosage / Q000494:pharmacology*; D000778:Anesthetics, Dissociative / Q000008:administration & dosage / Q000494:pharmacology*; D018685:Anesthetics, Inhalation; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects; D004285:Dogs / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D007268:Injections, Epidural / Q000662:veterinary; D007530:Isoflurane; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D011446:Prospective Studies; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology
D019162:Anesthetics, Combined; D000778:Anesthetics, Dissociative; D018685:Anesthetics, Inhalation; D007649:Ketamine; D007530:Isoflurane