7 Typical symptoms, although sometimes minor or even absent, include dyspnoea and chest pain. Primary spontaneous pneumothorax has an incidence of 18–28/100 000 cases in men and 1.2–6/100 000 in women. A chest CT scan 1 year later was reported normal. It was removed 4 days later and the patient could be discharged in good condition with no more clicks. Right: frontal view.Ī small apical chest drain was inserted. Electrocardiography showed a sinus rhythm of 78 b.p.m., QRS 88 ms, QRS-axis 88°, without repolarization disturbances, prominent R and S waves, most likely related to the slim constitution of the man, in absence of any sign for connective tissue disease ( Figure 1).Ĭhest computed tomography scan showing the left-sided pneumothorax. At the ED the chest radiograph was reported normal. Arterial blood gas, full blood count, and biochemistry results were normal, including haemoglobin (Hb), leucocytes, C-reactive protein, D-dimer level, and troponins, excluding pulmonary embolism and acute myocardial infarction.
There was a normal lung and heart auscultation except for the sporadic clicking sound on the left sternal edge, confirmed in the emergency department (ED). His vital parameters were reassuring: normal blood pressure, fever was absent, oxygen saturation was 99%. Physical examination revealed a fit young man with a body mass index of 18.3 kg/m 2. The patient had no other symptoms, in particular no shortness of breath. On such an occasion, he managed to record the sound digitally with his smartphone since it could be heard even without the use of a stethoscope ( Supplementary material online, Audio S1). The patient noticed that the clicking, popping sound had been sporadically present for 3 weeks and could be very loud at times. Another reason for his referral was a transient ‘click’ that could be heard on the left sternal edge during auscultation. Despite non-steroidal anti-inflammatory drug therapy, the symptoms persisted and therefore he presented at our emergency department. This was initially suspected to be a pericarditis secondary to the viral gastroenteritis. While the gastrointestinal symptoms disappeared completely, the chest pain persisted in mild amplitude. At that moment, he was suffering from a gastroenteritis. Three weeks previously he experienced an acute precordial sharp pain. He was a non-smoker and had never taken any illicit drugs. TimelineĪ 19-year-old man with no past medical history was referred to the hospital with chest pain and a strange precordial clicking. 5, 6 This case report can make this sound accessible to physicians taking care of patients presenting with audible clicks in association with dyspnoea and/or thoracic pain. 4 Despite its value in the differential diagnosis of left-sided pneumothorax, pneumomediastinum, and valvular pathology such as mitral valve prolapse, the sound itself has only rarely been recorded. Clinical cases already mention this pericardial knock in 1918 in gunshot wounds of the left chest 2, 3 and in 1928 in cases of spontaneous left-sided pneumothorax. Hamman 1 described this phenomenon in association with pneumomediastinum in 1937.
Hamman’s sign is a lesser-known clinical sign since it is very rare and only transiently present. The registration of these clicks (included in the online version of the article) will be useful in the future training of physicians to recognize this pathology. Differential diagnosis should be made with pneumomediastinum and valvular pathology such as mitral valve prolapse.
Audible clicks can be a key sign of left-sided pneumothorax.