The effects of oral diazepam premedication on blood gases.

Blood gas analysis was performed before and 1 h after 10 mg oral diazepam premedication on 50 adult male patients undergoing different surgical operations. There was a significant (p less than 0.01) decrease in arterial oxygen tension, a significant (p less than 0.01) increase in alveolar--arterial oxygen tension difference, and no significant change in arterial carbon dioxide tension or pH after administration of the drug. It is concluded that diazepam given by mouth 1 h before operation increases venous admixture. It is suggested therefore that oral diazepam premedication should be given cautiously to patients with impaired cardiorespiratory reserve, preferably without adding a narcotic drug.