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ULY CLINIC
ULY CLINIC
24 Septemba 2025, 14:42:23
Hamman’s sign
Hamman’s sign is a loud, crunching, or crackling sound heard over the precordium, synchronous with the heartbeat. It indicates mediastinal emphysema (pneumomediastinum) and may result from trauma, pneumothorax, or rupture of the trachea or bronchi.
Pathophysiology
Mediastinal emphysema occurs when air enters the mediastinum.
The heart’s contractions compress air-filled tissues, producing a characteristic crunching or crackling sound synchronous with each heartbeat.
Common causes include:
Traumatic rupture of trachea, bronchi, or esophagus.
Spontaneous pneumomediastinum (e.g., Valsalva maneuver, asthma).
Secondary to pneumothorax or barotrauma from mechanical ventilation.
Examination Technique
Patient positioning: Place the patient in the left lateral decubitus position.
Auscultation: Using the stethoscope, gently auscultate the precordium.
Observation: Listen for a loud, crunching, or popping sound that occurs in synchrony with each heartbeat.
Documentation: Record the timing, intensity, and location of the sound.
Clinical Features
Feature | Manifestation |
Sound quality | Loud, crunching, or crackling |
Timing | Synchronous with heartbeat |
Location | Precordium, most prominent in left lateral decubitus |
Associated conditions | Pneumomediastinum, pneumothorax, tracheal or bronchial rupture |
Symptoms | Chest pain, dyspnea, subcutaneous emphysema, sometimes asymptomatic |
Differential Diagnosis
Condition | Key Feature | Notes |
Pneumomediastinum | Hamman’s sign + chest pain | Air in mediastinum compresses tissues |
Pneumothorax | Dyspnea, decreased breath sounds | Hamman’s sign may be absent or minimal |
Pericardial rub | Scratchy sound synchronous with heartbeat | Usually in pericarditis; differs in quality |
Subcutaneous emphysema | Crepitus on palpation | May accompany Hamman’s sign if extensive |
Mediastinitis | Severe infection, fever, chest pain | Rare but life-threatening; auscultatory sounds may be overshadowed by systemic signs |
Pediatric considerations
Rare; usually secondary to trauma, foreign body aspiration, or severe asthma exacerbation.
Auscultation technique is the same, but gentle handling is essential.
Geriatric considerations
Mediastinal emphysema may occur after thoracic procedures, trauma, or barotrauma from ventilation.
High vigilance is needed due to coexisting cardiopulmonary disease.
Limitations
Hamman’s sign may be subtle or absent in mild cases.
Requires quiet environment and proper patient positioning.
Cannot localize the exact source of air leak without imaging.
Patient counseling
Explain that the sound is caused by air trapped in the mediastinum.
Emphasize the urgent need for evaluation, as underlying causes may be life-threatening.
Advise immediate reporting of worsening chest pain, shortness of breath, or swelling.
Conclusion
Hamman’s sign is an important auscultatory finding indicative of mediastinal emphysema, which may result from trauma, pneumothorax, or rupture of the trachea or bronchi. Careful auscultation in the left lateral position helps detect this sign, guiding urgent diagnostic and therapeutic interventions.
References
Hamman L. Spontaneous mediastinal emphysema. Bull Johns Hopkins Hosp. 1937;60:1–21.
Macia I, et al. Spontaneous pneumomediastinum: 41 cases. Eur J Cardiothorac Surg. 2007;31(6):1110–1114.
Kouritas VK, et al. Pneumomediastinum. J Thorac Dis. 2015;7(Suppl 1):S44–S49.
Cameron JL, Cameron AM. Current Surgical Therapy. 12th ed. Philadelphia: Elsevier; 2020.