PRN Antihypertensives in Hospitals: A Crisis of Precision or Pragmatism?

• Elevated blood pressure
• Hypertensive emergency
• Asymptomatic
• Antihypertensive management
• PRN medications
• Target-organ damage

Editor – High blood pressure (BP), the leading modifiable risk factor for cardiovascular disease, is a common finding in hospitalized patients, yet its management remains a subject of debate. One study found up to 72% of hospital admissions had elevated inpatient BP, with or without new or worsening target-organ damage.¹ Elevated inpatient BP can be grouped into two categories: (i) asymptomatic, and (ii) with signs of new or worsening target-organ damage, known as hypertensive emergency. Historical terms like hypertensive crisis and hypertensive urgency are subjective and may encourage unnecessary treatment. The new terminology includes: (i) hypertensive emergency (systolic BP/diastolic BP >180/110–120 mmHg with new or worsening target-organ damage), (ii) asymptomatic markedly elevated inpatient BP (systolic BP/diastolic BP >180/110–120 mmHg without new or worsening damage), and (iii) asymptomatic elevated inpatient BP (systolic BP/diastolic BP ≥130/80 mmHg without new or worsening damage). This updated terminology aims to reduce unnecessary treatment by emphasizing objective criteria over emotive language (Figure 1).

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Figure 1.

New terminology used to describe elevated blood pressure in the acute care setting. [SBP; systolic blood pressure; DBP, diastolic blood pressure]

Target-organ systems include the brain (eg, stroke, cerebral hemorrhage, hypertensive encephalopathy, or posterior reversible encephalopathy syndrome [PRES]), arteries (eg, aortic dissection, preeclampsia, eclampsia, HELLP [hemolysis, elevated liver enzymes, low platelets] syndrome), retina (eg, acute hypertensive retinopathy), kidneys (eg, acute kidney injury, thrombotic microangiopathy), and heart (eg, acute coronary syndrome, acute heart failure, pulmonary edema) — all of which are denoted by the mnemonic BARKH (Figure 2). The 2017 multi-society hypertension clinical practice guideline, published in the Journal of the American College of Cardiology in 2018, emphasizes immediate intervention for hypertensive emergencies to prevent target-organ damage. The American College of Cardiology and the American Heart Association recommend intensive care unit admission for continuous blood pressure monitoring and parenteral antihypertensive administration. For adults without compelling conditions, systolic BP should be reduced by no more than 25% within the first hour, aiming for 160/100 mmHg within 2 to 6 hours, and then cautiously to normal over 24 to 48 hours. In cases of compelling conditions like aortic dissection, severe preeclampsia, or pheochromocytoma crisis, systolic BP should be reduced to <140 mmHg within the first hour, and to <120 mmHg in aortic dissection cases. Preferred intravenous agents include nicardipine, clevidipine, sodium nitroprusside, and nitroglycerin, each with specific dosing guidelines to balance rapid blood pressure reduction with target-organ protection.²

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Figure 2.

Target-organ damage in hypertensive emergencies.

Asymptomatic markedly elevated BP (previously hypertensive urgency) is characterized by a systolic BP >180 mmHg and/or a diastolic BP >120 mmHg without signs of acute end-organ damage. It is not an uncommon practice amongst inpatient clinicians to prescribe as-needed antihypertensive medications to be administered above a specific BP threshold, allowing nurses to act independently. It is also currently being practiced to intensify home BP medications. Now, the question arises: is it truly necessary? Recent evidence suggests asymptomatic hospital patients with elevated BP are at risk for adverse outcomes from parenteral antihypertensive agents or oral agent up-titration during the inpatient stay. Veterans Association researchers examined records of 130,000 nonsurgical, non-intensive care inpatients (mean age 71) with scheduled antihypertensive medications and at least one systolic BP reading over 140 mmHg during hospitalization.³ About 28,000 patients (21%) received as-needed BP medications. After propensity-score matching, any as-needed BP medication use was associated with excess acute kidney injury (AKI; adjusted hazard ratio, 1.2), and intravenous as-needed BP medications were associated with even higher AKI risk (aHR, 1.6). Secondary analyses indicated as-needed BP medication recipients, compared with nonrecipients, had 1.5-fold greater risk for rapid BP drop and 1.7-fold higher incidence of a composite endpoint of myocardial infarction, stroke, or death.

The American Heart Association currently advises against routine pharmacological treatment for asymptomatic markedly elevated and asymptomatic elevated inpatient BP, emphasizing a cautious, patient-centered approach. Management should focus on verifying accurate BP measurement, addressing reversible causes (eg, pain, anxiety), and restarting home antihypertensive medications when appropriate, rather than initiating or intensifying therapy without clear evidence of benefit.⁴ Having said that, patients with persistently high inpatient BP readings, especially those with a history of high outpatient BPs or cardiovascular disease risk, may benefit from starting or intensifying antihypertensive medication. Future research should focus on refining treatment thresholds and strategies for managing elevated inpatient BP to ensure optimal patient outcomes while minimizing harm.

• Received January 20, 2025.
• Revision received March 13, 2025.
• Accepted March 24, 2025.