Conscious sedation with intermittent midazolam and fentanyl in electrophysiology procedures.

OBJECTIVES: To determine the safety and efficacy of intermittent midazolam and fentanyl conscious sedation for electrophysiology procedures (EP).

BACKGROUND: Intermittent midazolam and fentanyl conscious sedation was administered in 700 consecutive cases (175 radiofrequency ablations, 163 EP studies, 261 pacemakers, and 101 implantable cardioverter-defibrillators) for 471 patients (239 males, 51%) mean age 65 +/- 15 years. The mean dose of midazolam was 0.063 mg/kg/hr and fentanyl was 0.591 microgram/kg/hr.

METHODS: Cardiac rate and rhythm were monitored continuously, while blood pressure and arterial oxygen saturation were noninvasively assessed every 5 minutes. Drugs were administered in aliquots of 0.5 to 2.0 mg of midazolam and 6.25 to 25 micrograms of fentanyl as determined by clinical condition every 15 to 30 minutes.

RESULTS: There were no deaths. In no case was endotracheal intubation required. Mild hypoxemia (SaO2 > 80%, but < 90%) occurred in 17 cases (2.4%) and was easily reversed with verbal stimulation and oropharyngeal repositioning (12 cases, 1.7%), increased F1O2 (3 cases, 0.4%), or intravenous naloxone (2 cases, 0.3%). Reversible hypotension (systolic blood pressure < 90, but > 60 mmHg) occurred in 14 patients (2.0%) and was corrected with intravenous crystalloid bolus or flumazenil (10 cases, 1.4%) or inotrope infusion (4 cases, 0.6%). No patient stay was prolonged due to sedation. Only five patients (0.7%) had any recollection of the procedure, while two (0.3%) were aware of pain. All hypoxemic episodes occurred during the first hour, whereas 43% (6/14) of hypotensive episodes occurred after the first hour.

CONCLUSION: Conscious sedation with intermittent midazolam and fentanyl is safe and efficacious for a broad range of EP procedures.