Impact of Intravenous Antihypertensives on Outcomes Among Hospitalized Patients

Abstract

Background: Many hospitalized patients with acute elevations in blood pressure (BP) are treated with intravenous (IV) antihypertensive medications without evidence of benefit. This study investigated the effects of IV as-needed (PRN) antihypertensives on BP, hospital length of stay, and mortality.

Methods: We included hospitalized patients with an order for an IV PRN antihypertensive medication. We excluded patients with target organ damage. We performed multivariate analysis to assess whether the medication was independently associated with outcomes.

Results: 1,784 out of 5,680 patients (31%) had an administration of the PRN medication. Patients who received the medication had a longer hospital stay compared with patients with an order for the medication who did not receive it (4.9 ± 6.1 vs. 3.1 ± 4.1 days, P < 0.001). This remained statistically significant after adjusting for covariates. In-hospital mortality was higher in the group that received the medication (3.3% vs. 1.6%, P < 0.001), but this was not statistically significant on multivariate analysis. IV hydralazine caused the most significant reduction in BP and led to a shorter length of stay when compared with enalapril and labetalol. A total of 62% of patients received the medication for a systolic BP lower than 180 mm Hg.

Conclusions: Treating hypertension in the in-patient setting remains complex. Rapid lowering of BP can cause harm to patients, and this study showed that antihypertensive medication increased hospital length of stay. Once assuring no target organ damage, a strategic approach should be to treat modifiable factors and gradually reduce BP.

Keywords: PRN; as-needed antihypertensives; blood pressure; hospital stay; hypertension; mortality.