DANGER AT THE DEPTHS Pelonomi Firm 2 Dr T van Heerden Consultant: Dr Otto 30/04/2010

Our patient Mr Harding 34 yr No relevant medical history Technical, trimix diver

SCUBA “Self-contained underwater breating apparatus” Emergencies - Barotrauma - Decompression sickness - Nitrogen narcosis

Pathophysiology Boyle’s law

Alveolar damage Pneumothorax Pneumomediastinum / pneumopericardium Pulmonary venous gas emboli Systemic arterial gas emboli Pneumocardium

Clinical picture Pneumomediastinum -Fullness in chest -Pleuritic chest pain -Dyspnoea -Cough -Hoarseness -Dysphagia Pneumothorax -Dyspnoea -Chest pain -Tachycardia and hypotension -Cyanosis -Distended neck veins -Unilateral breath sounds, hyperresonant -Subcutaneous emphysema Arterial gas embolism Cerebral – focal motor, sensory or visual distrubances to seizures, LOC and death Cardiac – dysrhythmias, MI, cardiac arrest Classically: Haemoptysis

Predisposing factors General -Inexperience -Rapid ascent Medical Lung bullae or cysts Prev spontaneous pneumothorax Asthma COPD Emphysema and fibrosis Sarcoidosis Tuberculosis Acute respiratory disease with secretions

1.Cysts and bullae - Diffusion of air 2. Prev spontaneous pneumothorax - Contra-indication - Bilat pleurectomy - Normal lung functions - Normal post-op CT

3. Asthma Triggers: –Exertion –Inhalation of dry, compressed air –Hypertonic saline –Breathing against resistance British Thoracic Society –Wheeze –No symptoms –Normal lung functions –Negative exercise test –Monitor peak flow –Refrain if: Acute attack, requiring relief medication < 48hrs ↑ Diurnal peak flow variability > 20%

4. COPD Theoretical risk Reduced lung functions 5. Other Sarcoidosis Tuberculosis Cystic Fibrosis Ehlers-Danlos Marfan’s

Assessment History FEV1 > 80% FVC > 80% FEV1/FVC > 70% CXR Other CT

Long term effects Large lung volumes –Greater ↑ in vital capacity than FEV1 Reduced expiratory flow rates Vital capacity ↓ at increased rate Saturation diving

Outcome Severe Gr II decompression sickness High task load Rapid ascent Rescue attempt “Dennis” the first Coele in memory of Dennis Harding ( )

Further information Divers Alert Network DAN Southern Africa 24hr Hotline – PADI

? ? Questions ? ?