In the July issue of the Annals of Emergency Medicine, ACEP published a clinical policy focusing on critical issues in the emergency department evaluation and management of adult patients with asymptomatic elevated blood pressure. This is a revision of a clinical policy on asymptomatic hypertension that was published in 2006.

This clinical policy can also be found on ACEP’s website, www.acep.org, and has been accepted for inclusion on the National Guideline Clearinghouse website, www.guidelines.gov.

This clinical policy takes an evidence-based approach to answering two frequently encountered questions related to emergency department decision making.

Recommendations (Level A, B, or C) for patient management are provided based on the strength of evidence using the Clinical Policies Committee’s well-established methodology:

• Level A recommendations represent patient management principles that reflect a high degree of clinical certainty;
• Level B recommendations represent patient management principles that reflect moderate clinical certainty;
• Level C recommendations represent other patient management strategies based on Class III studies, or in the absence of any adequate published literature, based on consensus of the members of the ACEP Clinical Policies Committee.

During development, this clinical policy was reviewed and expert review comments were received from emergency physicians, family physicians, cardiologists, nephrologists, and individual members of the American Academy of Family Physicians, the American Heart Association Council for High Blood Pressure Research, the American Society of Nephrology, and the Emergency Nurses Association. Their responses were used to further refine and enhance this policy; however, their responses do not imply endorsement of this clinical policy.

Hypertension is a highly prevalent condition worldwide, carrying significant risk for cardiovascular, renal, and neurologic morbidity and mortality. Markedly elevated blood pressure can result in acute target organ injury (e.g. cardiovascular, renal, or neurologic) if left untreated over time. Acutely, when these complications are clinically apparent, evaluation and treatment of the elevated blood pressure is often initiated expeditiously. However, commonly, emergency department patients are found to have markedly elevated blood pressure in the absence of clinical signs or symptoms of acute target organ injury. In this latter situation recommendations for evaluation, treatment, and follow-up are less clear for emergency physicians. This ACEP policy focuses on patients with asymptomatic elevated blood pressure by reviewing the literature and making evidence-based recommendations relevant to the care of these patients in the emergency department.

Question 1: In ED patients with asymptomatic elevated blood pressure, does screening for target organ injury reduce rates of adverse outcomes?

• Level A recommendations. None specified.
• Level B recommendations. None specified.
• `Level C recommendations.

(1) In ED patients with asymptomatic markedly elevated blood pressure, routine screening for acute target organ injury (e.g, serum creatinine, urinalysis, ECG) is not required.

(2) In select patient populations (e.g, poor follow-up), screening for an elevated serum creatinine level may identify kidney injury that affects disposition (e.g, hospital admission).

While current literature and textbooks do not give a definitive answer to the question of “does screening for target organ injury in asymptomatic hypertension reduce rates of adverse outcomes,” recommendations can be derived from individual studies. Studies reviewed identified that screening was not routinely indicated, but showed that renal dysfunction of unknown immediate clinical significance could be detected in a small number of patients (up to 5%) by checking a serum creatinine. Unfortunately, the chronicity of this dysfunction was not always known and its impact on clinical outcomes was not evaluated. Further affecting the utility of the data was the limited generalizability of the patient populations and a lack of comparison data to patients without elevated blood pressure. Other screening, including the urinalysis, chest radiograph, and electrocardiogram were shown to be of no benefit.

Question 2: In patients with asymptomatic markedly elevated blood pressure, does ED medical intervention reduce rates of adverse outcomes?

• Level A recommendations. None specified.
• Level B recommendations. None specified.
• Level C recommendations.

(1) In patients with asymptomatic markedly elevated blood pressure, routine ED medical intervention is not required.

(2) In select patient populations (e.g, poor follow-up), emergency physicians may treat markedly elevated blood pressure in the ED and/or initiate therapy for long-term control. [Consensus recommendation]

(3) Patients with asymptomatic markedly elevated blood pressure should be referred for outpatient follow-up. [Consensus recommendation]

Recommendations for this critical question are again limited by a paucity of data. Emergency physicians must be careful not to blindly extrapolate longitudinal data on the benefits of blood pressure control over time to the acute setting of emergency medicine. Exemplifying this is a Cochrane review that challenges the dogma to treat symptomatic patients with markedly elevated blood pressure finding insufficient evidence to support or refute the practice. In asymptomatic patients, studies reviewed showed that no serious blood pressure–related adverse events occurred when delaying medical intervention until follow-up out to three months. This, in addition to a general acceptance that the rapid lowering of markedly elevated blood pressure in the asymptomatic patient has the potential to do harm, supports ACEP’s Level C recommendation. However, it must be noted that in selected social or clinical situations (e.g, poor follow-up, limited access to care), emergency physicians may choose to initiate treatment for markedly elevated blood pressure in the asymptomatic patient before discharge in order to gradually lower the blood pressure and/or initiate long-term control.

Emergency physicians should know there is a paucity of data supporting optimal evaluation, management, and follow-up of emergency department patients with asymptomatic elevated blood pressure. Future studies need to evaluate these strategies, both as they pertain to relevant patient outcomes and as they relate to the unique social and clinical situations that are typical in the acute care settings.

Dr. Wolf is associate professor and director of education in the Department of Emergency Medicine at the University of Colorado School of Medicine and Denver Health Medical Center; and assistant dean for advanced studies at the University of Colorado School of Medicine.