Abstract | OBJECTIVES: STUDY DESIGN: Randomized cross-over experimental trial. ANIMALS: Six mature, healthy Beagles (three males, three females) weighing 10.6 +/- 0.43 kg. METHODS: A 50-microg hour(-1) fentanyl patch was applied 36 hours prior to anesthesia. Anesthesia was induced at time 0 (t = 0). Each dog received four treatments: isoflurane + normothermia (ISO-NORM), isoflurane + hypothermia (ISO-HYPO), halothane + normothermia (HAL-NORM), and halothane + hypothermia (HAL-HYPO). Dogs were intubated and maintained at 1.5 times MAC. Animals in the hypothermia treatments were cooled to 35 degrees C during anesthesia. Serum fentanyl analysis was performed at -36, -24, -12, 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 18, and 26 hours. Direct arterial blood pressures and arterial blood gases were monitored. RESULTS: The mean body temperatures (+/-SEM) during the anesthetic period for the four treatments were: ISO-NORM = 37.7 +/- 0.07 degrees C, ISO-HYPO = 35.8 +/- 0.1 degrees C, HAL-NORM = 37.7 +/- 0.06 degrees C, and HAL-HYPO = 35.8 +/- 0.13 degrees C. The mean (+/-SEM) serum fentanyl concentrations (SFC) for both hypothermia treatments were significantly lower than baseline concentrations at t = 1 hour and persisted for the duration of anesthesia for the ISO-HYPO treatment but only from t = 1 to 2 hours for the HAL-HYPO treatment. Serum fentanyl concentrations returned to baseline within one hour of the end of anesthesia, regardless of body temperature. There were no significant differences between treatments for systolic or diastolic blood pressure but mean blood pressures were higher during normothermia versus hypothermia during the last hour of anesthesia. CONCLUSIONS AND CLINICAL RELEVANCE:
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Authors | Glenn R Pettifer, Giselle Hosgood |
Journal | Veterinary anaesthesia and analgesia
(Vet Anaesth Analg)
Vol. 31
Issue 2
Pg. 109-20
(Apr 2004)
ISSN: 1467-2987 [Print] United States |
PMID | 15053749
(Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)
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Chemical References |
- Analgesics, Opioid
- Anesthetics, Inhalation
- Isoflurane
- Fentanyl
- Halothane
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Topics |
- Administration, Cutaneous
- Analgesics, Opioid
(administration & dosage, pharmacokinetics)
- Anesthetics, Inhalation
(administration & dosage, pharmacology)
- Animals
- Blood Gas Analysis
(veterinary)
- Blood Pressure
(drug effects)
- Body Temperature
(drug effects)
- Cross-Over Studies
- Dogs
(physiology)
- Female
- Fentanyl
(administration & dosage, pharmacokinetics)
- Halothane
(administration & dosage, pharmacology)
- Hypothermia, Induced
(veterinary)
- Isoflurane
(administration & dosage, pharmacology)
- Male
- Preanesthetic Medication
(veterinary)
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