The Journal of pharmacology and experimental therapeutics
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J. Pharmacol. Exp. Ther. · Dec 1984
Porcine systemic and regional organ blood flow during 1.0 and 1.5 minimum alveolar concentrations of sevoflurane anesthesia without and with 50% nitrous oxide.
Effects of sevoflurane anesthesia on organ blood flow were examined in nine healthy isocapnic pigs using 15-mumol diameter radionuclide-labeled microspheres that were injected into the left atrium. Minimum alveolar concentration (MAC) of sevoflurane required to prevent 50% of the pigs from responding by gross purposeful movement to a noxious stimulus was found to be 2.66 +/- 0.20%. Hemodynamic measurements were made on each pig during the following five conditions: awake (control); 1.0 MAC of sevoflurane anesthesia; 2.66% (1.0 MAC) sevoflurane + 50% N2O anesthesia; 1.5 MAC of sevoflurane anesthesia; and 3.99% (1.5 MAC) sevoflurane + 50% N2O anesthesia. ⋯ However, during 3.99% sevoflurane anesthesia, brain-stem blood flow exceeded that at 2.66% sevoflurane anesthesia. Addition of N2O to pre-established concentrations of sevoflurane increased regional brain blood flow but cerebral and brain-stem blood flow exceeded awake value only during 2.66% sevoflurane + 50% N2O anesthesia. Transmural myocardial blood flow decreased in a dose-dependent manner during sevoflurane anesthesia but the subendocardial/subepicardial perfusion ratio remained at control value.(ABSTRACT TRUNCATED AT 250 WORDS)