When should a patient with hypertension (Htn) and potential comorbidities such as cardiovascular disease, diabetes, or chronic kidney disease be sent to the emergency department?

When to Send a Patient to the Emergency Department for Hypertension

Send a patient to the emergency department immediately if blood pressure is ≥180/120 mmHg AND there is evidence of acute target organ damage—this defines a hypertensive emergency requiring ICU admission and IV therapy. 1, 2

Critical Decision Point: Emergency vs. Urgency

The presence or absence of acute target organ damage is the sole determining factor for emergency referral, not the blood pressure number itself. 1, 2, 3

Hypertensive Emergency (SEND TO ER IMMEDIATELY)

Definition: BP ≥180/120 mmHg WITH acute target organ damage 1, 2

Specific signs of target organ damage requiring immediate ER transfer:

Neurologic:

• Altered mental status, somnolence, or lethargy 1
• Severe headache with vomiting (suggests encephalopathy) 1, 2
• Visual disturbances, cortical blindness 1
• Seizures or focal neurological deficits 1
• Acute stroke symptoms 1, 2

Cardiac:

• Chest pain suggesting acute myocardial ischemia or infarction 1, 2
• Acute heart failure with pulmonary edema (dyspnea, orthopnea) 1, 2
• Signs of aortic dissection (tearing chest/back pain, pulse differential) 1

Renal:

• Acute deterioration in renal function 1
• Oliguria or signs of acute kidney injury 2, 3

Ophthalmologic:

• Bilateral retinal hemorrhages, cotton wool spots, or papilledema on fundoscopy (malignant hypertension) 1, 2
• Note: Isolated subconjunctival hemorrhage is NOT target organ damage 2

Obstetric:

• Eclampsia or severe preeclampsia 1

Without treatment, hypertensive emergencies carry a 79% one-year mortality rate with median survival of only 10.4 months. 2, 3

Hypertensive Urgency (DO NOT SEND TO ER)

Definition: BP ≥180/120 mmHg WITHOUT acute target organ damage 1, 3

Management: Oral antihypertensive medications with outpatient follow-up within 2-4 weeks—hospital admission and IV medications are NOT indicated. 1, 3

Key evidence: Up to one-third of patients with severely elevated BP normalize before follow-up, and rapid BP lowering may be harmful. 1, 2, 3

Assessment Algorithm for the Outpatient Setting

Step 1: Confirm Blood Pressure Elevation

• Repeat BP measurement in both arms using proper technique 1
• Ensure patient is calm, seated, with pain/distress addressed 1

Step 2: Rapid Assessment for Target Organ Damage (Complete Within Minutes)

Brief neurological exam:

• Mental status, speech, visual fields, motor strength, gait 2, 3

Cardiac assessment:

• Chest pain, dyspnea, orthopnea, peripheral edema 2, 3
• Auscultate for pulmonary crackles, S3 gallop 2

Fundoscopic examination:

• Look specifically for bilateral hemorrhages, cotton wool spots, papilledema 1, 2
• Single subconjunctival hemorrhage does NOT constitute target organ damage 2

Renal assessment:

• History of decreased urine output 2
• Signs of volume overload 2

Step 3: Risk Stratification

Higher risk patients warrant more aggressive screening even with borderline symptoms: 4

• Age >60 years 4
• History of diabetes mellitus 4
• History of ischemic heart disease 4
• History of cerebrovascular accident 4
• Chronic kidney disease 4

In these high-risk patients, consider diagnostic testing even if asymptomatic: 4

• Basic metabolic panel (creatinine, electrolytes) 1, 2
• Urinalysis for proteinuria 1, 2
• ECG 1, 2
• Troponin if any cardiac symptoms 1, 2

Common Pitfalls to Avoid

Do not send to ER based on BP number alone without evidence of acute organ damage—this represents overtreatment and potential harm. 1, 2, 3

Do not confuse chronic hypertensive changes with acute emergencies:

• Left ventricular hypertrophy on ECG is chronic, not acute damage 2
• Chronic kidney disease with stable creatinine is not acute injury 2
• Isolated subconjunctival hemorrhage is not malignant hypertension 2

Do not dismiss transiently elevated BP in acute pain/distress—many patients normalize when the underlying stressor is addressed. 1

Do not rapidly lower BP in hypertensive urgency—this may cause cerebral, renal, or coronary ischemia in patients with chronic hypertension who have altered autoregulation. 1, 2, 3

Avoid beta-blockers in sympathomimetic-induced hypertension (cocaine, methamphetamine)—use benzodiazepines first. 1, 2

Special Circumstances Requiring Immediate ER Referral

Phaeochromocytoma crisis: Sudden severe hypertension with palpitations, diaphoresis, headache 1

Drug-induced hypertensive emergency: Sympathomimetics (cocaine, methamphetamine) causing acute organ damage 1

Pregnancy-related: Any severely elevated BP in pregnancy with symptoms suggesting preeclampsia/eclampsia 1, 2

Documentation for ER Referral

When sending a patient to ER, communicate:

• Specific BP readings and timing 2
• Specific symptoms/signs of target organ damage identified 2
• Relevant comorbidities (diabetes, CAD, CKD, CVA) 2, 4
• Current medications and adherence history 2
• Recent medication changes or non-compliance 2