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©2013 UpToDate ® Print Email Summary of key points and recommendations (continued) Recommendations on specific respiratory conditions Lung bullae or cysts increase risk of barotrauma and are contraindications to diving. Previousspontaneous pneumothorax is a contraindication unless treated bybilateral surgical pleurectomy and associated with normal lung functionand thoracic CT scan performed after surgery. Subjects with asthma should be advised not to dive if they have wheeze precipitated by exercise, cold, or emotion. Subjects with asthma may be permitted to dive if, with or withoutregular inhaled anti-inflammatory agents (step 2 of the BTSguidelines), they: Are free of asthma symptoms; Have normal spirometry (FEV1>80 percent predicted and FEV1/VC ratio >70 percent predicted); and Have a negative exercise test (<15 percent fall in FEV1 after exercise). Subjects withasthma should monitor their asthma with regular twice daily peak flowmeasurement and should refrain from diving if they have: Active asthma - that is, symptoms requiring relief medication in the 48 hours preceding the dive; An increased peak flow variability (more than 20 percent diurnal variation). COPDcarries a theoretical increased risk of barotrauma and reduced exercisetolerance. Subjects will probably be advised against diving on thebasis of reduced pulmonary function (FEV1 <80 percent predicted). Sarcoidosis has been associated with pulmonary barotrauma. Diving iscontraindicated in subjects who have active sarcoidosis. Those in whomsarcoidosis has resolved should have normal chest radiography andpulmonary function testing before being advised that they may proceedwith diving. Tuberculosis is apotentially transmissible disease that may cause residual impairment oflung structure and function. A subject with active tuberculosis shouldnot dive. After curative treatment they may dive if lung function andchest radiograph are normal. Cysticfibrosis is often associated with abnormal pulmonary function andincreased risk of pneumothorax. Diving is contraindicated in thosepatients who have pulmonary involvement. Fibrotic lungdisease reduces lung compliance and impairs gas transfer. Diving istherefore contraindicated in subjects who have fibrotic lung disease. Long term effects of diving on the lung

Cysticfibrosis is often associated with abnormal pulmonary function andincreased risk of pneumothorax. Diving is contraindicated in thosepatients who have pulmonary involvement. Fibrotic lungdisease reduces lung compliance and impairs gas transfer. Diving istherefore contraindicated in subjects who have fibrotic lung disease. Long term effects of diving on the lung Diverstend to have large lung volumes with proportionately greater increasesin vital capacity than in FEV1. This may be attributable in part to theeffects of repeatedly breathing dense gas through increased resistances. Divers may have reduced expiratory flow rates at low lung volumes, possibly reflecting small airway disease. Vital capacity of divers may decline with age at an increased rate. Saturation diving causes a fall in carbon monoxide transfer which, oncethe dive is completed, gradually returns to pre-dive values. Sources of specialist advice In the United Kingdom, advice on sports divingmay be sought from the medical referees of the British Sub Aqua Club,the Scottish Sub Aqua Club, or the Sub Aqua Association. Information isavailable on the UK Sport Diving Medical Diving Committee website(file://ww.uksdmc.co.uk). The Royal Navy Institute of Naval Medicine isalso willing to discuss cases with both divers and physicians. The Health and Safety Executive (HSE) isresponsible for commercial diving policy and regulation. Individualswho are diving at work require a current HSE certificate of fitness todive following examination by an approved medical examiner of divers. Reproduced from Thorax, British Thoracic Society guidelines on respiratory aspects of fitness for diving, volume 58, pages 3-13, Copyright © 2003, with permission from BMJ Publishing Group Ltd.