Low-Dose Droperidol and Its Association with QTc Interval Changes in Emergency Department Patients

The investigators plan to conduct ECG evaluation for QT interval both before and after patients are given 2.5 mg of droperidol. Specifically, a convenience sample of consenting adult patients, ages 18 years and older, who present to the ED, and are in a cardiac-monitored bed in the ED who, at the discretion of their treating physician, have an ECG recorded and then receive a dose of 2.5 mg of droperidol IV will be enrolled in our study. The investigators will then have a second ECG printed at least 5 minutes and no more than 30 minutes after the droperidol is given. Change in QT interval between the two ECGs will be documented. It may be necessary to review the EMR in order to document the time of droperidol administration.

These post-droperidol ECGs will not be stored in the electronic medical record nor read by a physician in real time. Treatment decisions regarding the patient's medical care in the ED will not be affected by these second ECGs; decisions about whether other ECGs may be needed will be made by the treating physician. The primary study outcome will be the percentage of the study population who experience a clinically significant increase in QTc after low-dose droperidol administration, defined as an increase in QTc of 20 ms or greater. Secondary outcome measures will be the mean change in QTc across the study population, and the percentage of the study population for whom the administration of low-dose droperidol is associated with an increase in QTc that re-classifies them as having a prolonged QTc (>450 ms in men and >470 ms in women).