Changes in arterial systolic, diastolic, and mean blood pressure were evaluated and compared in 34 dogs anesthetized with halothane or isoflurane and submitted to orthopedic surgeries. Two groups were formed each with 17 dogs. These animals were fasted for 12 hours before anesthesia induction. Anesthetic technique was premedication with 0.04mg/kg atropine intramuscular combined 1.5mg/kg morphine intramuscular. Anesthesia was induced with 6.0mg/kg propofol intravenously. Anesthesia was maintained with halothane in group I and isoflurane in group II. In both groups, nitrous oxide and oxygen in a 2:1 ratio was used as diluent for the inhalant. After 15 minutes of inhalation anesthesia, arterial blood pressures were recorded with a noninvasive blood pressure monitor in 15 minutes intervals for 90 minutes. Statistical analyses showed that there was a significant difference in systolic and diastolic pressures after 45 minutes. Differences in heart rate were not significant. In dos, general anesthesia with isoflurane maintained higher arterial blood pressures than those anesthetized with halothane which produced arterial hipotension from 45 to 75 minutes of anesthesia.
halothane; isoflurane; blood pressure; orthopedic surgery; canine
