A 61 year old male presented to Accident and Emergency with a gradual onset of a four day history of increasing breathlessness.There was no cough, chest pain or sputum produced.
He was an ex-smoker of fifty pack years. He had never smoked marijuana. Normal exercise tolerance was about forty metres on the flat. He could climb a flight of stairs with 2 stops but had not been able to do that over the last four days.
His past medical history included controlled hypertension and moderate chronic obstructive pulmonary disease for which budesonide 320 micrograms/formetrol dehydrate 9 micrograms inhalation powder 1 puff twice daily and tiotropium Handihaler 2.5 micrograms once daily were prescribed.
Oxygen saturations were 93% on air. He was afebrile and looked comfortable at rest. The pulse rate, number of breaths per minute and blood pressure were normal. Auscultation of the chest revealed decreased air entry in the whole of the right hemithorax. There was left sided tracheal deviation and the rest of the examination was normal, with no wheeze or peripheral oedema detected.
An urgent chest x-ray was performed (Figure 1). This was interpreted as showing a large right, secondary pneumothorax with some mediastinal shift to the left. However, the patient showed no respiratory compromise and as such no immediate action such as a needle decompression was taken. A referral was made to respiratory medicine for an urgent review and a possible intervention such as a chest drain insertion. This was serendipitous as the Accident and Emergency (A&E) team knew that a member of the pleural team was on call for respiratory medicine and readily available. Our hospital is a flagship emergency care centre where consultant cover and for respiratory medicine, pleural cover, is available 24 hours a day, 7 days a week.
Upon further review of the chest radiograph by the respiratory consultant, lung markings could be identified basally (Figure 2). It was felt that this was not a clear case of a pneumothorax and a chest drain was not immediately inserted.
Previous imaging and electronic notes were urgently reviewed.
The patient had lung function and lung volumes via pletysmograph in 2015. The forced expiratory volume in 1 second (FEV1) was 1.2 Litres (L) (41% predicted), forced vital capacity (FVC) 2.43L (67% predicted), total lung capacity (TLC) 7.33L (125% predicted), residual volume (RV) 230% predicted and alveolar volumes 4L (68% predicted). Transfer factor for carbon monoxide (TLCO) was 44% of predicted and the transfer coefficient of carbon monoxide (KCO) was 65% of predicted.
The above confirmed severe chronic obstructive pulmonary disease and empysema. The very high TLC and RV volumes suggested significant air trapping and the disparity between the alveolar volume and TLC suggested inhomogeneous gas mixing, a component of obstructive lung disease and bullous disease, which resulted in increased anatomical dead space.
Oxygen saturations from clinic were noted to vary between 89% on air to 94% on air. Left sided tracheal deviation was also noted to have been present from 2016 onwards.
Figures 3-5 from 2011 to late 2018 revealed a slowly enlarging bulla with increasing effacement of the normal lung parenchyma in the right lung. He had thus been diagnosed with giant bullous emphysema leading to vanishing lung syndrome. Figures 6 and 7 showed slices of a CT in 2013 showing a large bulla occupying approximately 75% of right hemithorax, arising from the right lower lobe and extending to the lung apex. There was minimal mediastinal displacement to the left in 2013, but the shift has become more pronounced on sequential imaging.
A ventilation-perfusion scan in 2016 showed that the left lung had 89% perfusion and the right 11%, with ventilation at 92% in left lung and 8% in the right. He had been referred for a pneumonectomy at the time but declined any intervention after meeting the cardiothoracic surgeons.
The patient had been initially managed conservatively and then not turned up for numerous appointments. He had been thus discharged from secondary care.
The chest radiograph depicted in Figure 1 was reviewed by the on call radiology service: the absence of a lung edge, the presence of lung markings as well as the lack of abrupt onset of symptoms such as pain and dyspnoea made a pneumothorax unlikely. The chest radiograph in Figure 1 looked similar to the last one done in 2018 and as such, a CT scan was not felt to be immediately indicated.
The patient was admitted and treated with 30 milligrams of prednisolone once a day for a possible non infective exacerbation of his obstructive lung disease. There was a clear documented plan that should he not improve, he would require an urgent CT scan to elucidate his anatomy further. After 48 hours, he felt markedly improved (oxygen saturations on air varied between 89% to 94% and his exercise tolerance improved to pre-admission levels) and had not required nebulised or oxygen therapy. He was thus discharged and outpatient follow up arranged.
He was given an alert card that said: ‘My right lung has a large bulla. This can look like a pneumothorax. Please do not put a chest drain in me if unsure of what is going on. Consider a CT scan. Ask for senior advice’
The patient then failed to attend for further clinic appointments. A telephone consultation took place: he mentioned his respiratory symptoms being stable and that he did not wish to have any secondary care follow up.