What is the appropriate first‑line management of pneumomediastinum in a patient with anorexia nervosa?

Management of Pneumomediastinum in Anorexia Nervosa

Pneumomediastinum in anorexia nervosa should be managed conservatively with observation, supportive care, and careful nutritional rehabilitation, as this complication typically resolves spontaneously within 2-3 weeks without requiring surgical intervention. 1, 2

Initial Assessment and Diagnosis

When pneumomediastinum is suspected in a patient with anorexia nervosa, immediate evaluation should focus on:

• Physical examination for subcutaneous crepitation, particularly in the axillae, intercostal spaces, between the scapulae, and along the spine 2
• Chest X-ray to confirm the diagnosis, which will show air in the mediastinum and may reveal extensive tissue emphysema, especially in the upper mediastinum 2
• CT scan for complete evaluation, as it can identify additional air collections in the retroperitoneal space, pneumopericardium, pneumoperitoneum, or pneumorrhachis that may not be visible on plain films 1, 2

Critical Differential: Ruling Out Esophageal Perforation

The most important initial step is distinguishing benign spontaneous pneumomediastinum from life-threatening esophageal perforation (Boerhaave syndrome). 3

• Patients with eating disorders who engage in purging behavior are at risk for both alveolar rupture (causing benign primary pneumomediastinum) and esophageal perforation 3
• Water-soluble contrast esophagography should be performed urgently if there is any clinical suspicion of esophageal perforation, particularly if the patient has severe chest pain, fever, tachycardia, or appears systemically unwell 4, 3
• Patients may deny or minimize vomiting history, which can delay diagnosis 3

Conservative Management Approach

The vast majority of pneumomediastinum cases in anorexia nervosa resolve with conservative medical management alone. 1, 2

Immediate Management:

• Observation in a specialized unit capable of monitoring for complications 1
• Rest and avoidance of activities that increase intrathoracic pressure (Valsalva maneuvers, straining, vigorous coughing) 2
• Oxygen supplementation if needed for symptomatic relief 2
• Pain management if chest discomfort is present 2

Nutritional Rehabilitation:

• Gradual, careful refeeding is essential but must be approached cautiously to avoid refeeding syndrome 4
• Cardiac complications of refeeding syndrome typically occur within the first week and are associated with severe malnutrition (BMI <70% ideal body weight), hypophosphatemia, and total parenteral nutrition 4
• Monitor electrolytes closely during refeeding, particularly phosphate levels 4
• Most cardiac manifestations of anorexia nervosa, including those related to malnutrition, are completely reversible with appropriate refeeding 4

Expected Clinical Course

• Clinical recovery typically occurs within 3 weeks 2
• Follow-up CT scan should demonstrate complete resolution of pneumomediastinum and subcutaneous emphysema 2
• The condition can recur with repeated vomiting episodes, particularly in patients with ongoing purging behaviors 5

Critical Pitfalls to Avoid

• Do not assume the pneumomediastinum is benign without ruling out esophageal perforation, especially in patients with a history of vomiting 3
• Do not overlook the patient's denial of vomiting, as individuals with eating disorders may obscure or delay diagnosis by denying symptoms or previous emesis 3
• Do not rush nutritional rehabilitation without careful monitoring for refeeding syndrome, which can cause life-threatening cardiac complications 4
• Do not discharge patients with severe malnutrition (BMI <10 kg/m²) without appropriate monitoring, as these patients are at highest risk for complications 1, 2

When Surgical Consultation is Needed

While conservative management is first-line, immediate surgical consultation is required if esophageal perforation is confirmed or if the patient develops signs of mediastinitis (persistent fever, worsening tachycardia, hemodynamic instability, or failure to improve with conservative measures). 4, 3