6.1 Hypertensive Crisis

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A rapid and severe elevation in BP is considered a hypertensive crisis. The presence or absence of target organ damage (TOD) is the guiding factor in classification of the crisis and ultimately the manner in which the crisis is treated.

Individuals with severe elevation of BP can be divided into three broad categories that can overlap.

  1. Severe hypertension: BP >180/110 mmHg without symptoms or acute signs of organ damage.
  2. Hypertensive urgencies, with BP >180/110mmHg without evidence of ongoing TOD.
  3. Hypertension emergencies often with BP >180/110 mmHg with evidence of ongoing TOD.

Hypertensive urgencies may be treated on an outpatient basis, by gradually reducing BP using oral antihypertensives. Hypertensive emergencies, on the other hand, require more immediate treatment with IV antihypertensives in an inpatient setting.

These patients may present in the following manner. Patients presenting with hypertensive crisis typically have had either chronically elevated BP or may be completely unaware that they have hypertension. Subtherapeutic treatment regimens, nonadherence, and drug-induced etiologies have been attributed to its development.

Persons with hypertensive urgency may experience severe headache, shortness of breath, nosebleed, or anxiety. With hypertensive emergency, the clinical presentation will depend on the particular organ that is undergoing injury, in addition to other symptoms, such as headache.

A rapid but thorough assessment must be performed to differentiate between urgency and emergency. The clinician should inquire about use of all medications, including OTC and herbal therapies, and illicit drug use. Medication adherence, including time of last dose, should be evaluated in all patients previously diagnosed with hypertension. BP should be confirmed in both arms, using correct measurement techniques.

Physical examination is an essential component of diagnosis. The examination should include assessment for signs indicative of heart failure, myocardial infarction, aortic dissection, hypertensive encephalopathy, cerebrovascular accident, renal failure, retinopathy, retinal hemorrhage, and papilledema3. CTscan, MRI, echocardiogram, or chest x-ray may also be necessary in assessing organ damage. Laboratory examinations should include a metabolic panel, urinalysis, a complete blood count, and urine toxicology.

Treatment Approach: Hypertensive Urgency

Hypertensive urgencies may be treated in an outpatient facility with oral antihypertensives; treatment consists of a slow lowering of BP over 24 to 48 hours. A reduction in BP of no more than 25% within the first 24 hours has been suggested. Adjusting current medication regimens to improve adherence or increasing the doses of current agents may be a sufficient management approach. However, additional agents may be necessary to attain desired results (Table 7).

Table 7: Drugs for the management of hypertensive urgency.

Table 7: Drugs for the management of hypertensive urgency.

Treatment Approach: Hypertensive Emergency

Hypertensive emergencies require immediate medical attention, including admission to the intensive care unit. Continuous cardiac monitoring, frequent measurement of urine output, and neurologic assessment are all necessary. Treatment with IV antihypertensive agents (TABLE 8) is warranted in this setting. Drug selection should be based on specific characteristics of the drug (i.e., adverse effects) and patient-specific attributes, such as volume status and the presence of comorbidities16.

Table 8: Treatment options for hypertensive emergencies.

Table 8: treatment options for hypertensive emergencies.

The primary goal would be to lower the mean arterial pressure by no more than 25% within the first hour, followed by BP reduction to 160/110-100 mmHg within the next 2 to 6 hours1.

BP reduction must be conducted in a controlled fashion in order to prevent organ hypoperfusion and subsequent ischemia or infarction3. However, in patients with aortic dissection, BP must be aggressively lowered3. Once the BP has stabilized and the risk of end-organ damage has dissipated, downward titration of the IV agent may begin, followed by conversion to oral therapy. The clinician should then attempt to ascertain causative factors for the event.