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|Test code||UA (macroscopic alone) or UAWM (with microscopy)|
|Performed by||Parnassus, Mission Bay & Mt. Zion Hematology|
|In House Availability||Test available 24 hours per day 7 days per week|
|Method||Dipstick with automated reader|
|Collection Instructions||First AM void preferred. Deliver sample to lab asap. Refrigerate samples if delivery is delayed. Testing is optimal when done within 1-2 hours of collection.|
|Container type||Urine cup|
|Amount to Collect||See preferred volume|
|Sample type||Random urine|
|Preferred volume||20 mL urine|
|UCSF Rejection Criteria||Samples received > 4 hours after collection.|
|Processing notes||Deliver all urinalysis samples to Hematology as soon as possible after receipt. If collection time is unknown, use receipt time for stability. Sample suitability from 2-4 hours is decided in Hematology|
|Synonyms||UA; Urine dipstick; Urine pH; Specific gravity, urine; Urine hemoglobin; Urine protein; Urine glucose; Urine nitrate; Urine Leukocyte esterase; Urine ketones; Urine bilirubin; Qualitative sugar, urine|
|Stability||2 hours at room temperature; 4 hours if refrigerated. For optimum results, the urine sample must be tested within 1-2 hours of collection, regardless of storage method.|
|Turn around times||STAT 1 hour, Routine 2 hours|
|Reflex?||Samples submitted with orders for Urinalysis with microscopic examination (UAWM) that are negative for Protein, Hemoglobin, Leukocyte esterase AND Ascorbic acid (Vit. C) will not be evaluated microscopically. The UAWM will be canceled and just the Macrocsopic urinalysis (UA) will be charged.
Samples submitted with orders for Urine macroscopic only (UA) that are positive for ascorbic acid (Vit. C) but negative for hemoglobin will be evaluated microscopically to rule out the presence of red cells. The UA will be canceled and a Urinalysis with microscopic examination will be ordered and billed (See additional information)
|Additional information|| Urinalysis samples should be delivered as soon as possible after collection. Delayed transport of an unpreserved urine may lead to loss of red cell casts and other formed elements Refrigeration of urine inhibits bacterial growth, but does not prevent the lytic effects of low specific gravity or alkaline pH. Urine crystal formation may be induced by refrigeration.
Note: Routine urinalysis in pediatric patients does not include testing for reducing substances, such as sugars galactose, lactose, fructose and maltose. If clinically indicated, this screening test for reducing substances may be ordered. Testing for congenital galactosemia is included in newborn screening programs in all 50 states in the U.S.
Specific Gravity: Reported as ≤ 1.005 to ≥ 1.030; the level found depends upon water intake; a fixed level around 1.010 which does not vary with the state of the patient's hydration suggests renal damage.
pH: Reported over the range of 5.0 to ≥ 9.0 and is diet-dependent; a level > 9.0 suggests infection with a urea-splitting organism.
Bilirubin: Because false-positive results for bilirubin may occur due to the intrinsic coloration of urine, positive results are confirmed by a chemical method.
Hemoglobin: Dipstick testing does not distinguish between hemoglobin and myoglobin; if no RBCs are seen in a freshly collected specimen, the possibility of myoglobinuria due to rhabdomyolysis can be evaluated by measuring serum CK, which will be markedly elevated. Captopril may reduce the test sensitivity.
Note: Ascorbic acid in urine may cause a false negative hemoglobin result on the macroscopic urinalysis. If ascorbic acid is detected and the hemoglobin is negative, a microscopic urinalysis examination will be performed. If only a macroscopic examinition (UA) was ordered on such samples the microscopic analysis will be reflexively ordered and separately charged for.
Nitrite: A positive urinary nitrite test is highly suggestive of a urinary infection, but in a low risk population may detect as few as 50% of infections found on culture, particularly if urinary frequency is high, the diet is low in nitrate substrate or, of course, if the organisms are not nitrite-producers.
Comparison of dipstick protein reading to 'scale' reading:
See also discussion of qualitative testing for preeclamptic patients under Protein, Total. Normal ranges for pH and Specific gravity from: Tietz Textbook of Clinical Chemistry, 4th ed., WB Saunders 2005
Urine ketones are not offered as a separate test. See Amino Acid, Quantitative, Urine
|Last Updated||1/27/2015 2:51:52 PM|