UREA - plasma or serum

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Specimen: 5 mL blood in lithium heparin or plain tube.

Method: Spectrophotometry.

Reference Interval:

Neonate:	1.0-4.0 mmol/L
Adult:	3.0-8.0 mmol/L

Application: Investigation of renal function.

Interpretation: Increased levels are seen with reduced glomerular filtration due to renal or pre-renal disease; bleeding into the gastrointestinal tract; hypercatabolic states. Reduced values are seen in pregnancy; with water retention; with reduced synthesis as a result of decreased protein intake, severe liver disease, or urea-cycle defects.

Reference: Dossetor JB. Ann Int Med 1966; 65: 1287-1299.

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