DANGER AT THE DEPTHS

Pelonomi Firm 2Dr T van Heerden

Consultant: Dr Otto30/04/2010

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 factorsGeneral- 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 (1966-2000)

Further information

Divers Alert Network

DAN Southern Africa

24hr Hotline – 011 254 1112

PADI

www.padi.com

? ? Questions ? ?