Evidence-based On-call

Acute renal failure

Prevalence
Causes
Clinical features
Investigations
Therapy
Prevention
Prognosis

Clinical features

Volume contraction

Look for low jugular venous pressure ^b

Use a well-lit room; lay the patient at 30° to 45° to horizontal; turn the head and look for the right internal jugular vein. Raise or lower the patient as required (normal patients may need to be laid almost flat). The JVP is the vertical height from the highest point of the pulsation to the angel of Louis.

Why?

A low jugular venous pressure makes an low central venous pressure more likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability
suspected hypovolaemia ^b (pre-test probability: 15%)	low central venous pressure (central venous pressure < 5 cm)	JVP low	3.4 (1.0 to 11)	38%
		JVP normal	1.0 (0.5 to 2.1)	15%
		JVP high	0.0 (0.0 to 1.5)	0%

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

Authors	C Clase , CM Ball
Reviewer	S Hsu
CAT Writers	C Clase , CM Ball