The Effect of Ether and Halothane on Blood Levels of Glucose, Pyruvate, Lactate and Metabolites of the Tricarboxylic Acid Cycle in Normotensive Patients During Operation

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Abstract
Arterial blood samples were studied for hematocrit, oxygen saturation, PaO2, acid base balance, glucose, pyruvate, lactate, excess lactate, citrate, [alpha]-ketoglutarate, malate, acetyl coenzyme A and adenosine triphosphate in adult patients anesthetized with ether or halothane-nitrous-oxide-oxygen. All types of operations except cardiovascular, neurological and obstetrical were included. No deviations from standard anesthetic of fluid replacement methods were employed except the substitution of saline for dextrose solutions. There was no evidence of shock in any case. Significant variation between anesthetic agents occurred in only 3 parameters. End of operation samples showed levels of total lactate, pyruvate and excess lactate consistently higher with ether than with halothane-nitrous-oxide-oxygen. Total acid increase was also greater with ether. Blood levels of acetyl coenzyme A and the three acids of the tricarboxylic acid cycle were not influenced by type of anesthetic agent or the presence or absence of exeess lactate. Lactate levels over 3 mEq./liter were associated with decreased blood levels of adenosine triphosphate, an effect more marked with ether than halothane. One possible explanation for higher lactate levels with ether is based on the sympathomimetic action of the agent A second, hypothetical explanation, suggests a depressant effect of ether on the intramitochondrial electron transport chain or the shuttle systems for transfer of reducing equivalents across the mitochondrial membrane.