DIVING AND ALTERED MENTAL STATE

Decompression illness includes decompression sickness (DCS, the bends) and cerebral arterial gas embolism (CAGE)

Any unusual symptoms post diving could be due to DCI and prompt a consult with RAH Hyperbaric unit Registrar/Consultant or David Teubner (see

)

Causes

	DCS	AGE
Mechanism	Nitrogen gas coming out of supersaturated solution and forming bubbles in the circulation or tissues following depressurisation during dive ascent.	Pulmonary barotrauma leading to gas moving from the alveolus into the left circulation and embolising to the brain.
Dive History	Long/Deep Limits reached	Rapid Ascent
Contributing factors	Flying Dive at alttitude Fatigue/Overexertion Dehydration	Inexperience 'Out of air'
Medical history	Fever/Hypothermia Obesity	COAD Patent foramen ovale
Onset of symptoms	Progressive	Rapid
Predominant organ affected	Spinal Paraesthesia Sacral involvement	Brain Confusion Seizures
LOC	Uncommon	Common
Associated symptoms	DCS I

MANAGEMENT

Treatment of DCI has 4 key points:

Positioning – keep supine, DO NOT sit or stand for any reason at all (esp. with AGE)

Oxygen – 100% oxygen administered via a bag and mask, continuous high flow circuit or CPAP machine (no PEEP)

Fluids – DCI patients usually hypovolaemic – give NS, keep urine output >1ml/kg/hr

Referral and transport to a recompression facility.

Dr. David Teubner MBBS FACEM