Blood Pressure
Corey Diamond, PharmD
In hospital settings, elevated BP without symptoms is observed in up to 70% of patients, even among those who usually have normal BP levels. While well established guidelines exist for managing chronic hypertension in outpatient care, there is a lack of clear recommendations for addressing asymptomatic BP elevations in hospitalized patients. In the absence of standardized protocols, clinicians frequently opt to lower BP reactively using as-needed medications, either as single doses or recurring administrations. Preliminary evidence suggests that treatment of asymptomatic hypertension in the hospital setting may incur potential risks, such as acute kidney injury (AKI).
The authors of a retrospective cohort study published in JAMA Internal Medicine on November 25, 2024, attempted to assess the risks of AKI and other adverse effects from as-needed BP medication administration in hospitalized patients within the Veterans Affairs (VA) hospital system. The researchers found evidence supporting the theory that as-needed BP medication increases the risks of AKI.
Design
Canalas and colleagues conducted a retrospective cohort analysis within the U.S. VA hospital system using a target trial emulation approach that aimed to replicate the structure of a randomized controlled trial using observational data. The study included adult veterans admitted to non-ICU medical or surgical floors between October 2015 and September 2020.
To be eligible, patients had to have been hospitalized for at least 3 days, received at least one scheduled BP medication within the first 24 hours of admission, and experienced at least one systolic BP reading above 140 mm Hg during their stay. Patients who underwent surgery or required acute BP lowering were excluded.
Participants were divided into two groups: those who received at least one dose of as-needed BP medication (either as a single dose or on a recurring basis) and those who were managed with scheduled BP medications alone. The primary outcome was the development of AKI during hospitalization. Secondary outcomes included a rapid BP reduction of more than 25% within 3 hours of medication administration and a composite measure of major adverse events, including myocardial infarction, stroke, or death.
Results
The study seemed to confirm that using as-needed BP medications in hospitalized veterans was linked to a higher risk of AKI and other serious outcomes. Among the over 130,000 patients analyzed, 21% received at least one as-needed BP medication. Those in this group were 23% more likely to develop AKI compared with patients who only received scheduled BP medications. The risk was particularly elevated with I.V. administration, which showed a stronger association with AKI compared with oral medication use.
Additionally, patients who received as-needed BP medications had a 150% greater likelihood of experiencing a rapid—more than 25%—drop in systolic BP within 3 hours of administration. The authors hypothesized that this rapid decrease in BP may contribute to end-organ damage, particularly in individuals with preexisting CVD.
The composite outcome (myocardial infarction, stroke, or death) was also significantly higher in the as-needed medication group, with a 169% increased risk. When examined individually, myocardial infarction risk nearly tripled, while stroke risk doubled compared to nonusers.
Discussion
The study’s findings suggested that as-needed BP medication use in hospitalized patients may do more harm than good, particularly due to its association with AKI and other serious outcomes. The authors highlighted that “there is at least equipoise regarding the utility of as-needed BP medication use for asymptomatic BP elevations in hospitals,” meaning that the risks and benefits are uncertain enough to warrant further investigation. The authors argue that these results support the need for prospective trials to determine safer, evidence-based approaches to inpatient hypertension management rather than relying on reactive BP lowering. ■