Efficacy and safety of a new protocol for continuous infusion of midazolam and fentanyl and its effects on patient distress during electrophysiological studies.

Electrophysiological studies are often distressing for patients. We devised a regime of continuous infusion of midazolam and fentanyl during electrophysiological studies without the presence of a specialist anaesthetist. The effects on key hemodynamic and respiratory variables and level of sedation were evaluated in detail in the first 775 patients. The safety of this practice was evaluated in 1,344 consecutive patients. Doses were calculated according to patients' weight and age. A mean total dose of 26 mg of midazolam and 115 mcg of fentanyl were infused. Satisfactory sedation was achieved in 97% of patients. The mean duration of procedure was 188 +/- 90 minutes. Complete amnesia of the procedure was obtained in 87% of patients. Sedation caused clinically insignificant changes in respiratory rate, oxygen saturation, end-tidal CO2 and blood pressure. There were no major complications related to sedation. Upper airway obstruction, usually minor, occurred in 42% and some restlessness in 20% of sedated patients. The assistance of a specialist anesthetist was required in 0.3% of sedated patients for management of restlessness, hypoventilation, or obstructive sleep apnea. The amount of distress experienced by sedated patients (n = 775) was significantly less compared to a previous series of nonsedated patients (n = 775) undergoing electrophysiological studies (P < 0.001). The degree of distress experienced by patients during electrophysiological studies can be reduced significantly by sedation with intravenous midazolam and fentanyl. Continuous infusion is an efficient, safe, and effective way of administering midazolam and fentanyl.