A 16 year old female of Korean background presented to the emergency department with sudden onset left-sided chest pain, palpitations and shortness of breath. The patient reported left-sided dull parasternal chest pain, radiating to the left jaw and neck, exacerbated by deep inspiration, leaning forwards or lying supine. There was no reported trauma, coughing or vomiting.
The patient reported 10kg of weight loss over the past 12 months, attributed to restrictive eating secondary to study-related stress. She also reported amenorrhoea for 9 months. She denies any past medical history and denied smoking or illicit substances.
Physical examination showed a blood pressure of 93/64 mmHg, heart rate of 59 beats per minute, respiratory rate of 16 breaths per minute, and body temperature of 36.3 degrees Celsius. Her height was 154cm, weight 34kg, and body mass index 14.3 kg/m2. There was anterior chest wall tenderness, maximal over left parasternal margin, especially in the 2nd intercostal space. There were no signs of subcutaneous emphysema in the neck or axillae. Cardiorespiratory and abdominal examination findings were normal.
Blood tests including full blood count, renal function, electrolytes and troponin were all within normal range. ECG demonstrated sinus rhythm and no ischaemic changes. The chest x-ray was documented in the patient medical record as having no concerning findings, and the patient was discharged home with simple analgesia and a plan for follow-up with her GP.
The following day, the patients chest x-ray was reported by the radiologist and the patient was contacted and advised to return to hospital. Chest x-ray showed gas tracking towards the base of the neck and a pleural reflection along the left paramediastinal location with appearances concerning for pneumomediastinum. A curvilinear line projecting at the level of the fourth intercostal space was suspicious for a right pneumothorax. [Fig 1]
On return to the emergency department, physical examination demonstrated the following: temperature of 35.3 degrees Celsius, heart rate 40-50 beats per minute, blood pressure 95/60, respiratory rate of 18, oxygen saturation of 95% on room air and there was subcutaneous emphysema over the neck and chest.
A computed tomography scan with oral contrast was performed, which demonstrated large volumes of bilateral subcutaneous emphysema extending along the chest wall and into the neck, and bilateral trace apical pneumothoraces. There were no signs of oesophageal perforation[Fig 2].
The patient was admitted and required multiple rapid responses for hypotension and bradycardia. Further history elucidated two years of exercises to lose weight, six months of restrictive eating and a weight loss of at least 20kg. The diagnosis of anorexia nervosa was confirmed and the patient was commenced on nasogastric feeds, electrolyte supplementation and frequent monitoring for refeeding syndrome.
Within 2 weeks her pneumomediastinum resolved spontaneously, as confirmed on a chest x-ray performed for review of nasogastric tube position[Fig 3].
The nasogastric tube feeds were progressively weaned and meals plans were updated. The patient was discharged with a weight of 43.5kg and BMI of 18.3 km/m
2.