Cardiovascular and respiratory response to intravenous diazepam, fentanyl, and methohexital in dental outpatients.

The cardiovascular and respiratory responses to a combination of diazepam and methohexital (D-M) were compared to those from a combination of diazepam, fentanyl, and methohexital (D-F-M). Both caused significant tachycardia after administration and during surgery. The D-F-M combination caused a significant decrease in both respiration rate and oxygen saturation. Surgeons preferred this combination for the production of sedation and cooperation of patients. Comparison of efficacy to toxicity suggests that the increase in patient cooperation for the D-F-M combination is at the expense of respiratory depression. The use of oxygen supplementation and monitoring of respiration is recommended during the use of the combination.