Management of spontaneous pneumothorax: British Thoracic Society Pleural Disease Guideline 2010.

INTRODUCTION The term ‘pneumothorax’ was first coined by Itard and then Laennec in 1803 and 1819 respectively, and refers to air in the pleural cavity (ie, interspersed between the lung and the chest wall). At that time, most cases of pneumothorax were secondary to tuberculosis, although some were recognised as occurring in otherwise healthy patients (‘pneumothorax simple’). This classification has endured subsequently, with the first modern description of pneumothorax occurring in healthy people (primary spontaneous pneumothorax, PSP) being that of Kjærgaard in 1932. It is a significant global health problem, with a reported incidence of 18e28/100 000 cases per annum for men and 1.2e6/100 000 for women. Secondary pneumothorax (SSP) is associated with underlying lung disease, in distinction to PSP, although tuberculosis is no longer the commonest underlying lung disease in the developed world. The consequences of a pneumothorax in patients with pre-existing lung disease are significantly greater, and the management is potentially more difficult. Combined hospital admission rates for PSP and SSP in the UK have been reported as 16.7/100 000 for men and 5.8/100 000 for women, with corresponding mortality rates of 1.26/million and 0.62/ million per annum between 1991 and 1995. With regard to the aetiology of pneumothorax, anatomical abnormalities have been demonstrated, even in the absence of overt underlying lung disease. Subpleural blebs and bullae are found at the lung apices at thoracoscopy and on CT scanning in up to 90% of cases of PSP, 6 and are thought to play a role. More recent autofluorescence studies have revealed pleural porosities in adjacent areas that were invisible with white light. Small airways obstruction, mediated by an influx of inflammatory cells, often characterises pneumothorax and may become manifest in the smaller airways at an earlier stage with ‘emphysema-like changes’ (ELCs). Smoking has been implicated in this aetiological pathway, the smoking habit being associated with a 12% risk of developing pneumothorax in healthy smoking men compared with 0.1% in nonsmokers. Patients with PSP tend to be taller than control patients. 11 The gradient of negative pleural pressure increases from the lung base to the apex, so that alveoli at the lung apex in tall individuals are subject to significantly greater distending pressure than those at the base of the lung, and the vectors in theory predispose to the development of apical subpleural blebs. Although it is to some extent counterintuitive, there is no evidence that a relationship exists between the onset of pneumothorax and physical activity, the onset being as likely to occur during sedentary activity. Despite the apparent relationship between smoking and pneumothorax, 80e86% of young patients continue to smoke after their first episode of PSP. The risk of recurrence of PSP is as high as 54% within the first 4 years, with isolated risk factors including smoking, height and age >60 years. 15 Risk factors for recurrence of SSP include age, pulmonary fibrosis and emphysema. 16 Thus, efforts should be directed at smoking cessation after the development of a pneumothorax. The initial British Thoracic Society (BTS) guidelines for the treatment of pneumothoraces were published in 1993. Later studies suggested that compliance with these guidelines was improving but remained suboptimal at only 20e40% among non-respiratory and A&E staff. Clinical guidelines have been shown to improve clinical practice, 19 compliance being related to the complexity of practical procedures and strengthened by the presence of an evidence base. The second version of the BTS guidelines was published in 2003 and reinforced the trend towards safer and less invasive management strategies, together with detailed advice on a range of associated issues and conditions. It included algorithms for the management of PSP and SSP but excluded the management of trauma. This guideline seeks to consolidate and update the pneumothorax guidelines in the light of subsequent research and using the SIGN methodology. Traumatic pneumothorax is not covered by this guideline.