BTS guidelines Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010 Andrew MacDuff,1 Anthony Arnold,2 John Harvey,3 on behalf of the BTS Pleural Disease Guideline Group 1Respiratory Medicine, Royal INTRODUCTION between the onset of pneumothorax and physical Infirmary of Edinburgh, UK The term ‘pneumothorax’ was first coined by Itard activity, the onset being as likely to occur during 2 Department of Respiratory and then Laennec in 1803 and 1819 respectively,1 sedentary activity.13 Medicine, Castle Hill Hospital, Cottingham, East Yorkshire, UK and refers to air in the pleural cavity (ie, inter- Despite the apparent relationship between 3North Bristol Lung Centre, spersed between the lung and the chest wall). At smoking and pneumothorax, 80e86% of young Southmead Hospital, Bristol, UK that time, most cases of pneumothorax were patients continue to smoke after their first episode of secondary to tuberculosis, although some were PSP.14 The risk of recurrence of PSP is as high as 54% Correspondence to recognised as occurring in otherwise healthy within the first 4 years, with isolated risk factors Dr John Harvey, North Bristol ‘ ’ fi > 12 15 Lung Centre, Southmead patients ( pneumothorax simple ). This classi ca- including smoking, height and age 60 years. Hospital, Bristol BS10 5NB, UK; tion has endured subsequently, with the first Risk factors for recurrence of SSP include age, [email protected] modern description of pneumothorax occurring in pulmonary fibrosis and emphysema.15 16 Thus, healthy people (primary spontaneous pneumo- efforts should be directed at smoking cessation after Received 12 February 2010 thorax, PSP) being that of Kjærgaard2 in 1932. It is the development of a pneumothorax. Accepted 4 March 2010 a significant global health problem, with a reported The initial British Thoracic Society (BTS) incidence of 18e28/100 000 cases per annum for guidelines for the treatment of pneumothoraces men and 1.2e6/100 000 for women.3 were published in 1993.17 Later studies suggested Secondary pneumothorax (SSP) is associated that compliance with these guidelines was with underlying lung disease, in distinction to PSP, improving but remained suboptimal at only although tuberculosis is no longer the commonest 20e40% among non-respiratory and A&E staff. underlying lung disease in the developed world. The Clinical guidelines have been shown to improve consequences of a pneumothorax in patients with clinical practice,18 19 compliance being related to pre-existing lung disease are significantly greater, the complexity of practical procedures20 and and the management is potentially more difficult. strengthened by the presence of an evidence Combined hospital admission rates for PSP and SSP base.21 The second version of the BTS guidelines in the UK have been reported as 16.7/100 000 for was published in 200322 andreinforcedthetrend men and 5.8/100 000 for women, with corre- towards safer and less invasive management sponding mortality rates of 1.26/million and 0.62/ strategies, together with detailed advice on a range million per annum between 1991 and 1995.4 of associated issues and conditions. It included With regard to the aetiology of pneumothorax, algorithms for the management of PSP and SSP anatomical abnormalities have been demonstrated, but excluded the management of trauma. This even in the absence of overt underlying lung guideline seeks to consolidate and update the disease. Subpleural blebs and bullae are found at the pneumothorax guidelines in the light of subse- lung apices at thoracoscopy and on CT scanning in quent research and using the SIGN methodology. up to 90% of cases of PSP,5 6 and are thought to Traumatic pneumothorax is not covered by this play a role. More recent autofluorescence studies7 guideline. have revealed pleural porosities in adjacent areas < SSP is associated with a higher morbidity that were invisible with white light. Small airways and mortality than PSP. (D) obstruction, mediated by an influx of inflammatory < Strong emphasis should be placed on cells, often characterises pneumothorax and may smoking cessation to minimise the risk of become manifest in the smaller airways at an earlier recurrence. (D) stage with ‘emphysema-like changes’ (ELCs).8 < Pneumothorax is not usually associated Smoking has been implicated in this aetiological with physical exertion. (D) pathway, the smoking habit being associated with a 12% risk of developing pneumothorax in healthy CLINICAL EVALUATION smoking men compared with 0.1% in non- < Symptoms in PSP may be minimal or smokers.9 Patients with PSP tend to be taller than absent. In contrast, symptoms are greater control patients.10 11 The gradient of negative in SSP, even if the pneumothorax is rela- pleural pressure increases from the lung base to the tively small in size. (D) apex, so that alveoli at the lung apex in tall indi- < The presence of breathlessness influences viduals are subject to significantly greater the management strategy. (D) distending pressure than those at the base of the < Severe symptoms and signs of respiratory lung, and the vectors in theory predispose to the distress suggest the presence of tension development of apical subpleural blebs.12 pneumothorax. (D) Although it is to some extent counterintuitive, The typical symptoms of chest pain and dyspnoea there is no evidence that a relationship exists may be relatively minor or even absent,23 so that ii18 Thorax 2010;65(Suppl 2):ii18eii31. doi:10.1136/thx.2010.136986 BTS guidelines a high index of initial diagnostic suspicion is required. Many chest imaging, so that conventional chest films are no longer patients (especially those with PSP) therefore present several easily available in clinical practice in the UK or in many other days after the onset of symptoms.24 The longer this period of modern healthcare systems. The diagnostic characteristic is time, the greater is the risk of re-expansion pulmonary oedema displacement of the pleural line. In up to 50% of cases an air- (RPO).25 26 In general, the clinical symptoms associated with fluid level is visible in the costophrenic angle, and this is occa- SSP are more severe than those associated with PSP, and most sionally the only apparent abnormality.33 The presence of patients with SSP experience breathlessness that is out of bullous lung disease can lead to the erroneous diagnosis of proportion to the size of the pneumothorax.27 28 These clinical pneumothorax, with unfortunate consequences for the patient. manifestations are therefore unreliable indicators of the size of If uncertainty exists, then CT scanning is highly desirable (see the pneumothorax.29 30 When severe symptoms are accompa- below). nied by signs of cardiorespiratory distress, tension pneumo- thorax must be considered. Lateral x-rays The physical signs of a pneumothorax can be subtle but, char- These may provide additional information when a suspected acteristically, include reduced lung expansion, hyper-resonance pneumothorax is not confirmed by a PA chest film33 but, again, and diminished breath sounds on the side of the pneumothorax. are no longer routinely used in everyday clinical practice. Added sounds such as ‘clicking’ can occasionally be audible at the cardiac apex.23 The presence of observable breathlessness has Expiratory films influenced subsequent management in previous guidelines.17 23 These are not thought to confer additional benefit in the routine e In association with these signs, cyanosis, sweating, severe assessment of pneumothorax.34 36 tachypnoea, tachycardia and hypotension may indicate the presence of tension pneumothorax (see later section). Supine and lateral decubitus x-rays Arterial blood gas measurements are frequently abnormal in These imaging techniques have mostly been employed for patients with pneumothorax, with the arterial oxygen tension trauma patients who cannot be safely moved. They are generally < 31 (PaO2) being 10.9 kPa in 75% of patients, but are not required less sensitive than erect PA x-rays for the diagnosis of pneu- if the oxygen saturations are adequate (>92%) on breathing mothorax37 38 and have been superseded by ultrasound or CT 31 room air. The hypoxaemia is greater in cases of SSP, the PaO2 imaging for patients who cannot assume the erect posture. being <7.5 kPa, together with a degree of carbon dioxide reten- tion in 16% of cases in a large series.32 Pulmonary function tests Ultrasound scanning are poor predictors of the presence or size of a pneumothorax7 Specific features on ultrasound scanning are diagnostic of and, in any case, tests of forced expiration are generally best pneumothorax39 but, to date, the main value of this technique avoided in this situation. has been in the management of supine trauma patients.40 The diagnosis of pneumothorax is usually confirmed by imaging techniques (see below) which may also yield informa- Digital imaging tion about the size of the pneumothorax, but clinical evaluation Digital radiography (Picture-Archiving Communication Systems, should probably be the main determinant of the management PACS) has replaced conventional film-based chest radiography strategy as well as assisting the initial diagnosis. across most UK hospitals within the last 5 years, conferring considerable advantages such as magnification, measurement and IMAGING contrast manipulation, ease of transmission, storage and repro- Initial diagnosis duction. Relatively few studies have addressed the specific issue < Standard erect chest x-rays in inspiration are recom- of pneumothorax and its diagnosis, and these have tended to mended for the initial diagnosis of pneumothorax, focus on expert diagnosis (by consultant radiologists) and the rather than expiratory films. (A) more discriminating departmental (rather than ward-based) < The widespread adoption of digital imaging (PACS) workstations. Even so, some difficulties were found in the diag- 41 42 requires diagnostic caution and further studies since the nosis of pneumothorax in early studies. Since then there have presence of a small pneumothorax may not be imme- been technological advances, such that digital imaging may now diately apparent.