Prehospital Diuretics

Although there is no proven link between early diuretic administration and improved outcome in patients with congestive heart failure (CHF), diuretic use is common in the prehospital setting. Little is known about the appropriateness or benefits of this practice. Using a database from a single emergency medical service, investigators identified all instances of prehospital furosemide use during a 12-month period and reviewed patients’ emergency department and hospital charts.

Furosemide use was deemed appropriate when the primary or secondary ED or hospital diagnosis included CHF or pulmonary edema, or when the brain-type natriuretic peptide (BNP) level was >400 pg/mL. Use was deemed inappropriate when the diagnoses did not include CHF or pulmonary edema, the BNP level was <200 pg/mL, or when intravenous fluids were given in the ED. Furosemide was considered potentially harmful in patients with a diagnosis of sepsis, dehydration, or pneumonia who did not have a diagnosis of CHF or pulmonary edema or a BNP level >400 pg/mL.

Of 146 patients who received furosemide in the prehospital setting, 144 had complete records available. CHF was diagnosed in 58%. Intravenous fluids were administered upon hospital arrival in 23%. Furosemide use was considered appropriate in 58%, inappropriate in 42%, and potentially harmful in 17%. Nine of the 146 patients died. Seven of those who died did not have a diagnosis of CHF.

Comment: Compared with other medications for CHF, such as nitrates and morphine, diuretics work very slowly, so the likelihood of benefit from administration in the prehospital setting is low. This study shows that, at least in one EMS system, prehospital use of diuretics is as likely to be inappropriate as appropriate and might even be harmful in many cases. It is unlikely that these findings are limited to a single system or to use of diuretics for CHF. A similar evaluation of the use of other medications in the prehospital setting would be worthwhile.

— Daniel J. Pallin, MD, MPH