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Coma

Causes
Clinical features
Investigations
Immediate management
Prevention
Prognosis
Clinical features

Look for raised intracranial pressure by assessing the fundi. 
Look for retinal vein pulsation c  

Why?

Retinal vein pulsation makes raised intracranial pressure unlikely

Patient Target Disorder and
Reference Standard		 Diagnostic Test LR+
(95% CI) 		Post-test Probability LR-
(95% CI) 		Post-test Probability
suspected raised intracranial pressure c
(pre-test probability: 23%) 		raised intracranial pressure
(lumbar puncture or follow-up) 		absence of retinal vein pulsation 8.1
(5.3 to 13) 		70% 0.0
(0.0 to 0.077) 		0%

Expiry date: September 2003
Levels of Evidence used in grading these guides

Authors   W   Whiteley , CM   Ball
Reviewer   M   Daniel
CAT Writers   W   Whiteley , CM   Ball