When to send a patient with orthostatic hypotension (low blood pressure upon standing) to the emergency department (ED)?

When to Send a Patient with Orthostatic Hypotension to the Emergency Department

Patients with orthostatic hypotension should be sent to the emergency department when they have symptoms of organ hypoperfusion, syncope, or a systolic blood pressure drop of ≥40 mmHg that does not rapidly normalize within 40 seconds of standing.

Definition and Assessment of Orthostatic Hypotension

Orthostatic hypotension (OH) is defined as:

• A decrease in systolic BP ≥20 mmHg or diastolic BP ≥10 mmHg within 3 minutes of standing 1
• Initial OH: BP decrease >40 mmHg systolic or >20 mmHg diastolic within 15 seconds of standing 1
• Delayed OH: OH occurring beyond 3 minutes of standing 1

Proper assessment requires:

• Having the patient sit or lie for 5 minutes before measuring baseline BP 1
• Measuring BP at 1 minute and/or 3 minutes after standing 1
• Assessing for symptoms of cerebral hypoperfusion

Emergency Department Referral Criteria

Send to ED immediately if:

1. Symptomatic severe hypotension:

   • Systolic BP <90 mmHg with symptoms 1
   • Signs of organ hypoperfusion (altered mental status, chest pain, dyspnea)

2. Syncope or near-syncope with any of these features:

   • Recent onset without clear situational trigger
   • Associated with cardiac symptoms (chest pain, palpitations)
   • Occurring with minimal provocation or without warning
   • Evidence of injury from falling

3. Severe orthostatic drop:

   • Initial OH with BP decrease >40 mmHg systolic that does not rapidly normalize 1
   • Any orthostatic drop associated with persistent symptoms despite sitting/lying down

4. Signs of underlying acute condition:

   • Evidence of volume depletion with hemodynamic instability
   • Signs of internal bleeding
   • Fever with hypotension (suggesting sepsis)
   • New-onset severe OH in patients on antihypertensive medications

Risk Stratification

High-risk features requiring urgent evaluation:

• Elderly patients (>85 years) with significant comorbidities 1
• Patients with known cardiovascular disease and new or worsening OH
• Patients with diabetes and autonomic neuropathy with severe symptomatic OH
• Patients with Parkinson's disease with new severe OH
• Frail patients with falls due to OH

Moderate-risk features (consider ED referral based on clinical judgment):

• Moderate symptoms with BP that normalizes within 3 minutes of sitting/lying down
• Patients with known OH who have worsening symptoms despite treatment
• Patients with new medications known to cause OH with moderate symptoms

Low-risk features (outpatient management appropriate):

• Asymptomatic OH detected on routine examination
• Mild symptoms that resolve quickly with position change
• Chronic, stable OH with minor symptom changes

Management Considerations

For patients not requiring emergency care:

1. Non-pharmacological approaches:

   • Increase fluid and salt intake
   • Compression garments
   • Physical counter-maneuvers
   • Avoid precipitating factors (rapid position changes, hot environments)

2. Medication review:

   • Adjust or discontinue medications that can worsen OH
   • Common culprits: antihypertensives, diuretics, alpha-blockers, antidepressants

3. Follow-up recommendations:

   • Early follow-up (within 1-2 weeks) for patients with new-onset OH managed as outpatients
   • Home BP monitoring with position changes
   • Clear return precautions if symptoms worsen

Common Pitfalls to Avoid

1. Failure to recognize OH as a marker of increased mortality risk

   • OH is associated with increased cardiovascular risk and all-cause mortality 2

2. Overlooking medication causes

   • Always review medication list for potential contributors to OH

3. Inadequate assessment technique

   • Not allowing sufficient rest before baseline measurement
   • Not measuring BP at appropriate intervals after standing

4. Missing neurogenic OH

   • Characterized by blunted heart rate response (<10 bpm increase) 1
   • May indicate autonomic failure requiring specialized evaluation

5. Focusing only on BP numbers rather than symptoms

   • The presence and severity of symptoms should guide emergency referral decisions
   • Some patients tolerate significant BP drops without symptoms

Remember that orthostatic hypotension is not just a benign finding but can indicate serious underlying pathology and is associated with increased mortality risk. When in doubt about the severity or if adequate monitoring cannot be ensured, err on the side of caution and refer to the emergency department.