5-HYDROXYINDOLE ACETIC ACID, URINE - 24 HOUR

Test Documentation
Specimen Required
Patient Preparation: Patients should not eat avocados, bananas, butternuts, cantaloupe, dates, eggplant, grapefruit, hickory nuts, honeydew, kiwi fruit, melons, nuts, pecans, pineapple, plums, tomatoes, or walnuts for a 48 hour period prior to start and duration of collection. Could result in falsely elevated 5-HIAA excretion. Medications affecting metabolism of serotonin must be avoided at least 72 hours before and during collection. Patients should also avoid coffee, tea, and tobacco.
Collect 24 hour urine (see collection instructions below). Send 25.0 mL acidified urine (10.0 mL minimum) refrigerated in a screw-capped plastic urine container. Record total volume on test requisition and specimen label.
24 hour urine collection is to begin, and this urine is discarded. Thereafter all urine must be collected until the end of the scheduled time. Preferred method of collection for 24 hour collection: collect urine with 25 mL of 6N HCl at start of collection to maintain pH between 2 and 3. Refrigerate urine during collection (critical). Mix the collection well before removing aliquot. Record total volume on test request and on container label. Send 25.0 mL (10.0 mL minimum) refrigerated in a screw-capped plastic urine container.

Alternate Specimen
Alternate method of 24 hour collection with preservative: Refrigerate urine during collection (critical) and add 25.0 mL 6N HCl to the entire collection within 4 hours of collection completion. Mix collection well, and check pH to ensure pH is between 1 and 3. Send a 25.0 mL urine aliquot (10.0 mL minimum) refrigerated in a screw-capped plastic urine container. Record total volume on container label. Alternate method of 24 hour collection without preservative: Collect 24 hours urine and keep refrigerated throughout collection. Mix well and send 25.0 mL urine (10.0 mL minimum) refrigerated in a screw-capped plastic urine container. Record total volume on container label.

Methodology
High Performance Liquid Chromatography

Stability
With preservative: Room Temperature: 10 days; Refrigerated: 14 days; Frozen: 1 year
Without preservative: Room Temperature: Unacceptable; Refrigerated: 7 days; Frozen: 14 days

Reference Range
<10 mg/24 hours
Urine Creatinine:
Males:   1.0-2.0 g/24 hours  
Females:   0.8-1.8 g/24 hours  

Performed
Monday, Wednesday, Friday

Turnaround Time4-6 days
Test CodeU5HIA
CPT-4 Code (s)
83497, 82570
LOINC Codes
Total volume   19153-6  
Creatinine   2162-6  
5HIAA, 24 hr urine   1695-6  

Warde
Medical
Laboratory