Initial Management of Pneumomediastinum
Most cases of pneumomediastinum should be managed conservatively with observation, oxygen supplementation, and symptom control, as the mediastinal tissues will spontaneously resorb the air without specific intervention. 1, 2
Immediate Diagnostic Confirmation
Obtain chest radiography (anteroposterior and lateral views) to confirm the diagnosis, though CT scanning of the thorax should be performed when life-threatening conditions need exclusion, particularly to evaluate for pneumothorax, pneumopericardium, or epidural pneumatosis 1, 3
CT scan is the preferred screening tool and should be obtained in all cases - it detects pneumomediastinum in 100% of cases compared to only 15% detection rate on plain radiographs, and can identify patients at high risk for major aerodigestive tract injury with 100% sensitivity and 85% specificity 4
Physical examination should specifically assess for subcutaneous emphysema affecting the face, neck, and chest, and auscultate for Hamman's crunch (a "crunching" sound timed with the cardiac cycle) 2
Risk Stratification for Major Injury
The critical decision point is determining whether invasive evaluation is needed:
If CT findings are NOT suspicious for major aerodigestive tract injury (80% of cases), proceed directly to conservative management without endoscopic evaluation 4
If CT findings ARE suspicious for major aerodigestive tract injury (20% of cases), perform bronchoscopy and esophagography - only 37% of these suspicious cases will have an injury requiring operative intervention 4
In the blunt trauma cohort managed with observation alone (60% of patients), there were zero delayed diagnoses, missed injuries, or complications, supporting the safety of selective rather than mandatory invasive evaluation 4
Conservative Management Protocol
Implement the following conservative measures for uncomplicated pneumomediastinum:
Provide high-flow oxygen supplementation (10 L/min) to accelerate resorption of mediastinal air up to four times faster than room air 5
Avoid sedatives and hypnotics, as they can mask clinical deterioration and compromise respiratory drive 1
Institute close cardiopulmonary monitoring for potential complications including tension pneumomediastinum, which can cause hemodynamic compromise mimicking cardiac tamponade 2, 6
Monitor vital signs every 4-6 hours: respiratory rate, heart rate, blood pressure, and oxygen saturation 5
Specific Contraindications and Precautions
Prohibit air travel until radiographic resolution is confirmed, as pressure changes during flight can worsen pneumomediastinum 1
Do NOT routinely perform esophagography - in spontaneous pneumomediastinum cases, esophagography was performed in 35% of patients and was invariably negative for leak 7
Distinguish spontaneous pneumomediastinum from esophageal perforation: spontaneous cases present in younger patients, with lower white cell counts, and without pleural effusion 7
Indications for Escalation
Proceed to surgical decompression with chest drains if:
Tension pneumomediastinum develops with hemodynamic instability requiring vasopressors 6
Signs of cardiac tamponade physiology appear due to increased intrapulmonary pressure on venous return 2
Major aerodigestive tract injury is confirmed (laryngeal injury, tracheal disruption, or esophageal perforation) requiring operative intervention 4
Expected Clinical Course
Most patients with uncomplicated spontaneous pneumomediastinum respond well within 5-7 days and can be discharged after symptom resolution 3
Mean hospitalization duration is 1.8 days for spontaneous cases 7
Obtain follow-up chest radiography at 2-4 weeks to confirm complete resolution before clearing patients for air travel (typically requires 6 weeks) 5, 1
Mortality with conservative management is essentially zero for uncomplicated cases, though tension pneumomediastinum carries 40% mortality if not promptly recognized 6, 7