RESUMO
OBJECTIVE: To compare the effects of oral diazepam, lorazepam and alprazolam premedication on venous admixture. MATERIAL AND METHODS: One hundred fifty patients divided in three groups were included in the study. The venous admixture was determined using the ISO-shunt nomogram. The values obtained 90 minutes after administration of the drugs were compared with the values before the drug administration. The Student's t-test was applied to find out the significance. RESULTS: These were highly significant change in increase in venous admixture (Qs/Qt) in group I patients 90 minutes after premedication as compared to premedication values. There was statistically insignificant difference in venous admixture (Qs/Qt) in group II and group III patients 90 minutes after premedication as compared to premedication values. CONCLUSION: From the present study it can be concluded that 2 mg of oral lorozepam given 90 minutes before surgery to healthy patients have significant effects on venous admixture. However, the effects of alprazolam and diazepam had no significant effect on venous admixture.