One night many years ago, I was called to a 79-year-old man who lived alone, complaining of sudden onset of chest pain of two hours' duration.
I found the patient lying on an ancient collapsing sofa in his large kitchen. Although he was registered with my partner, I had come across him before.
The patient had troublesome COPD but refused to stop smoking. I remembered his colourful language when I tried to get him to give up after he suffered a very bad chest infection.
He did not appear unduly distressed despite his protestations of severe pain, and he could speak in full sentences.
He had a respiratory rate of 26 breaths per minute, and he did not look cyanosed - there was no pulse oximetry back then. His temperature was 37.2oC, BP 175/95mmHg and heart rate 102bpm. There was no peripheral oedema and his JVP was not raised.
I listened to his chest, and he told me that he had a chest infection a week ago that was treated with antibiotics, so it could not be his lungs, it must be his heart.
He asked me to give him something for the pain, which he indicated was sharp and more to the right than truly central. There was no radiation to the arms or neck.
He was somewhat barrel-chested, so given his COPD it was not surprising that the breath sounds were poor on the left with some diffuse rhonchi, but they were even more difficult to hear on the right. I considered a differential diagnosis.
The pain seemed too lateral to be cardiac and he described it as sharp and stabbing. I wondered about a pulmonary embolus as he had spent some time in bed with his recent chest infection, but there was no evidence of DVT in either leg.
Pneumothorax was a possibility, although this short stocky man did not match the usual profile of tall, thin and young people. I percussed his chest - it was hyper-resonant on the right - and checked for vocal resonance, which was absent on the right. His breathing was getting worse, so I rang for an ambulance.
Confirmation by X-ray
My suspicions of a pneumothorax were confirmed by X-ray. I learnt that expiratory chest X-rays are not recommended in pneumothorax1 and if a posteroanterior X-ray is normal, a lateral chest or lateral decubitus view should be performed.
The incidence is about 18-28/100,000 per year for men and 1.2-6/100,000 for women. My patient had a spontaneous secondary pneumothorax, associated with his underlying COPD. In spontaneous primary pneumothorax, there is no underlying disease and by definition, there is no apparent precipitating event in either.
Mortality rates are low, about 1.26 per million per year in men and less in women. In otherwise healthy patients with primary pneumothorax, subpleural blebs and bullae are found in up to 90% of cases at thoracoscopy. Smoking plays a part, as the lifetime risk for men who smoke may be as high as 12% compared with 0.1% in non-smokers.
The clinical picture is not a reliable indicator of pneumothorax size, and it is notable that as many as 40% of patients do not seek medical advice for several days.
My patient was treated with intercostal tube drainage, but most cases of primary pneumothorax can be treated with simple aspiration as first-line treatment if intervention is required. Some pneumothoraces will reabsorb without intervention and only require observation. A tension pneumo-thorax is an emergency requiring rapid intervention.
My patient was fortunate, as only a 10% pneumothorax in a patient with moderate COPD can rapidly cause respiratory failure and hypotension. Other lung diseases that can cause secondary pneumothorax include asthma, cystic fibrosis, sarcoidosis, tuberculosis and pneumocystis associated with HIV/AIDS.
- Dr Barnard is a former GP from Fareham, Hampshire
1. Henry M, Arnold T, Harvey J. Thorax 2003; 58: ii39-ii52.