Is your patient at increased risk? Understanding the basics of diving-related respiratory problems

When evaluating a patient's fitness to dive, the history taking includes a careful search for respiratory and cardiac problems. Evaluation of pulmonary function is usually limited to spirometry, although methacholine challenge testing may be necessary to confirm asthma. Graded exercise testing is important for patients with cardiovascular risk factors. Contraindications to scuba diving include irreversible airway obstruction, gas-trapping lung lesions, and cardiovascular disease that limits exercise tolerance or increases risk of sudden death. Underwater diving accidents may result in decompression sickness or barotrauma; complications may include pneumothorax, subcutaneous air, and pulmonary vascular gas emboli. Administration of oxygen and intravenous fluid therapy may be required initially for diving accident victims. After stabilization, hyperbaric oxygen therapy may be necessary for patients who have decompression sickness or arterial gas embolism.