Continuous transcutaneous O2 and CO2 monitoring during conscious sedation for oral surgery.

Continuous transcutaneous oxygen and carbon dioxide monitoring during conscious sedation using diazepam, fentanyl, and methohexital indicates that hypoxia occurs in all patients maintained on room air; 36% of the patients maintained on room air showed a decrease in transcutaneous oxygen of greater than 20 mg Hg. Although the use of supplemental O2 prevented hypoxia, the combination of diazepam, fentanyl, and methohexital depressed all of the patient's carbon dioxide chemoreceptors, resulting in a rise in carbon dioxide in the oxygen-supplemented patients as well as in the patients who were maintained on room air. The need for supplemental oxygen in patients sedated with diazepam, fentanyl, and methohexital is clearly established.