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 (recommended): The bladder must be emptied at the time the 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 refrigerated 25 mL aliquot container, minimum of 10 mL.

Alternate Specimen
Refrigerate urine during collection (critical) and add preservative to the entire collection within 4 hours of completing. Mix the collection well before checking the pH. Ensure pH is between 1-3. Record total volume on test request and on container label. Send refrigerated 25 mL aliquot container (10 mL minimum).

Methodology
High Performance Liquid Chromatography

Stability
With preservative: Room Temperature: 3 days; Refrigerated: 7 days; Frozen: 1 month
Without preservative: Room Temperature: 24 hours; Refrigerated: 24 hours; Frozen: 7 days
Preservative must be added before sample is submitted for testing.

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