Comparative study between the effects of total intravenous anesthesia with propofol and balanced anesthesia with halothane on the alveolar-arterial oxygen tension difference and on the pulmonary shunt.

Inhalation anesthesia with halothane, inhibiting hypoxic pulmonary vasoconstriction, causes an increase in intrapulmonary shunt development as well as an increase of alveolar-arterial oxygen tension difference. In contrast, total intravenous anesthesia with propofol, as with other intravenous anesthetics, should not alter pulmonary gas exchange. The present study was carried out using two groups of patients of similar age, sex and weight, who were subjected to neurosurgical procedures. One group was under general inhalational anesthesia with halothane and the other group under total intravenous anesthesia with propofol. In a simple clinical manner and applying established formulae, the determination of intrapulmonary shunt and alveolar-arterial oxygen tension difference showed a significant increase after 120 min in the halothane group, whereas the group that received propofol did not show any significant variation. We therefore conclude that propofol, different from halothane, does not affect the pulmonary gas exchange.