Introduction The diagnosis and management of acute decompensated heart failure (HF) in the prehospital setting can be challenging. The objectives of this study are to evaluate the appropriateness of furosemide use by Emergency Medical Services (EMS) and its association with adverse outcomes.

Methods This study was a multi-centre health records review of EMS patients who received prehospital furosemide or had an emergency department (ED) diagnosis of HF. We included acutely ill patients ≥50 years of age with shortness of breath transported by land EMS. Univariate and logistic regression analyses were performed to determine associations between furosemide use and serious adverse outcomes (acute renal failure, intubation, vasopressors or death).

Results The study population consisted of 330 patients (N=58, furosemide given by EMS but no HF diagnosed in ED; N=110, furosemide given, HF diagnosed; N=162, no furosemide given, HF diagnosed). The median dose of intravenous furosemide was 80 mg (range 20–80 mg). Serious adverse outcomes occurred in 61 patients (19.0%, 23.6% and 14.8% of the three groups, respectively; p=0.18). The adjusted ORs for adverse events with furosemide use was 0.62 (95% CI 0.33 to 1.43) in patients with a diagnosis of HF and 1.14 (95% CI 0.58 to 2.23) in those without.

Conclusions More than a third of patients who received prehospital furosemide did not have an HF diagnosis, suggesting that the prehospital diagnosis of HF can be challenging. Serious adverse outcomes were identified in all patient groups and we found no statistically significant associations between furosemide use and adverse events.