What is the appropriate emergency department workup for a patient presenting with anorexia?

Emergency Department Workup for Anorexia Nervosa

The ED workup for a patient with suspected anorexia nervosa must include comprehensive vital signs with orthostatics, weight and BMI calculation, complete blood count, comprehensive metabolic panel with electrolytes, and an ECG—these are non-negotiable baseline assessments that directly impact mortality risk. 1

Initial Physical Assessment

The physical examination should focus on identifying life-threatening complications:

• Vital signs assessment (critical for mortality risk stratification):

  • Temperature
  • Resting heart rate (bradycardia is common and dangerous)
  • Blood pressure
  • Orthostatic vital signs (pulse and blood pressure changes from lying to standing—a key indicator of hemodynamic instability)

• Anthropometric measurements:

  • Current weight and height
  • Calculate BMI (or percent median BMI/BMI percentile/Z-score for pediatric patients)

• Physical appearance examination looking specifically for:

  • Signs of malnutrition (muscle wasting, lanugo hair, brittle nails)
  • Evidence of purging behaviors (Russell's sign on knuckles, dental erosions, posterior oropharyngeal bruising, parotid/salivary gland swelling) 2

1

Focused History

While obtaining vital signs and labs, gather this targeted information:

• Weight history: Maximum weight, minimum weight, recent changes
• Eating behaviors: Restrictive eating patterns, food avoidance, binge eating episodes
• Compensatory behaviors: Self-induced vomiting, laxative use, diuretic use, excessive exercise, diet pill use
• Time preoccupation: Percentage of day spent thinking about food, weight, body shape
• Co-occurring psychiatric conditions: Depression, anxiety, suicidality (critical given high suicide risk in AN) 3
• Prior eating disorder treatment and response

1

Mandatory Laboratory Testing

All patients require these labs—no exceptions:

• Complete blood count (CBC): Identifies anemia, leukopenia, thrombocytopenia from malnutrition
• Comprehensive metabolic panel including:
  • Electrolytes (hypokalemia, hyponatremia, hypochloremia from purging)
  • Liver enzymes (hepatic dysfunction)
  • Renal function tests (prerenal azotemia, chronic kidney disease from laxative abuse)
  • Glucose (hypoglycemia risk)

1

Electrocardiogram

An ECG is mandatory in all patients with restrictive eating disorders or severe purging behaviors because of the risk of fatal arrhythmias from:

• Electrolyte abnormalities (particularly hypokalemia and hypomagnesemia)
• QTc prolongation
• Bradycardia
• Other conduction abnormalities

1

Common Pitfalls to Avoid

Do not be falsed reassured by normal or even elevated BMI—patients with bulimia nervosa or atypical anorexia can have normal weight but still have life-threatening electrolyte abnormalities and cardiac complications 2. The severity of medical complications correlates with the severity of behaviors, not just weight.

Do not skip orthostatic vital signs—this is one of the most sensitive indicators of hemodynamic compromise and helps determine whether the patient requires admission 4, 5.

Do not dismiss bradycardia as "athletic"—in the context of restrictive eating, bradycardia represents cardiovascular adaptation to starvation and signals significant medical risk 6.

Recognize that patients often minimize symptoms and may actively avoid detection 3—maintain high clinical suspicion even with vague presenting complaints like fatigue, weakness, dizziness, or syncope.

Screening Tool

Consider using the SCOFF questionnaire for rapid screening when eating disorder is suspected but not obvious 4:

• Do you make yourself Sick because you feel uncomfortably full?
• Do you worry you have lost Control over how much you eat?
• Have you recently lost more than One stone (14 pounds) in a 3-month period?
• Do you believe yourself to be Fat when others say you are too thin?
• Would you say that Food dominates your life?

Disposition Planning

After completing the workup, the ED physician must determine medical stability and need for admission versus psychiatric referral. The comprehensive review of systems should identify any acute medical complications requiring inpatient medical management before psychiatric placement 1. Coordination with psychiatry, nutrition, and outpatient eating disorder specialists is essential for safe disposition 1.