Incidence of Adverse Events with Prehospital Use of Droperidol for Nausea or Vomiting

In 2019, droperidol was re-introduced for the treatment of nausea or agitation among emergency medical services (EMS) agencies. Despite a reduced dose used for nausea/vomiting compared to agitation, patients may still experience unwanted sedation. Some protocols recommend an even lower dose for certain patients, such as older adults (age ≥65 years), to avoid oversedation. However, there are limited data to support this practice. We aimed to identify the incidence of adverse events following the use of droperidol for nausea and vomiting and secondarily whether older patients had an increased likelihood of adverse events.

We performed a retrospective observational cohort study of a convenience sample of patients treated by 29 EMS agencies for nausea/vomiting with droperidol and transport to one of 9 hospitals between March 2022 and December 2023. We identified the incidence of adverse events including hypotension (systolic blood pressure <90mmHg), hypoventilation (respiratory rate <10 or end tidal carbon dioxide >50mmgHg), hypoxia (pulse oximetry <90% or need for supplemental oxygen), or decreased mental status (GCS <15) either prehospital or in the emergency department. Additionally, we performed a multivariable logistic regression to evaluate the association of adverse events with older age, controlling for sex, weight, route of administration, and if any other sedative was given.

A total of 284 cases were included and most (90.1%) received a dose of 1.25 mg. At least one adverse event was experienced by 44 (15.5%) patients, most commonly decreased mentation (GCS <15; n = 24, 8.5%). Hypoxia was experienced by 19 (6.7%) patients, mostly in older adults (n = 12, 13.2%) while hypotension or hypoventilation was experienced by <5%. In multivariable analysis, older patients had a similar odds of adverse events compared to other adults (OR 1.79, 95% CI 0.91-3.51).

We identified an adverse event in about 15% of prehospital patients receiving droperidol for nausea and vomiting, most commonly mild sedation, with very limited serious adverse events. Incidence of sedation was similar among older patients and other adults. Further investigation is warranted to evaluate effectiveness versus adverse events with different droperidol doses and compared to other antiemetics.