24 Hr urine (for adult patients only):

U1 bottle

Spot urine (for paediatric patients only):

Plain bottle

Volume: 10 mL

No

Guideline for Specimen Collection

1. Obtain plain urine containers (U1 bottle) for collection of 24 Hr urine. The containers should be stored in cool place during collection. (One single 24 hour urine sample collected during symptomatic period is suggested. Three consecutive 24 hour urine collections is generally NOT recommended.)
   
   
2. Female patients should avoid urine collection during menstrual period.
   
   
3. Patients on certain drugs may have potential physiological interferences with the test. Please refer to the List of Interfering Drugs for Catecholamines and Metanephrines for more details. Patient should NOT stop or change any prescribed drugs without prior approval from the attending doctors.
   
   
4. Patients should avoid coffee, tea, bananas, chocolate, cocoa and vanilla for at least 24 hours before, and during specimen collection.
   
   
5. Stress period like acute illness, malignant hypertension or recent myocardial infarction, and also vigorous or prolonged exercise prior to urine collection may increase the endogenous secretion of adrenaline affecting the results.

6. At the beginning of the urine collection, empty the urinary bladder and discard this urine. This time represents the beginning of the 24 hour period (e.g. 08:30 a.m. on Day 1). Collect all urine passed over the next 24 hours and add the urine to the urine containers and mix. At the end of the 24 hour period (i.e. 08:30 a.m. on Day 2), empty the urinary bladder and add this sample to the urine containers.
   
   
7. Record the date and time of commencement and completion of urine collection.
   
   
8. Return the urine sample and request form together, as soon as possible after the completion of the collection.
   
   

List of Interfering Drugs for Catecholamines and Metanephrines

The drugs listed below may adversely affect the test results of catecholamines and metanephrines. If possible, discontinue these drugs for at least 1 week before and till the end of urine collection.  (Source of reference: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, 6e, 2017)

Liquid chromatography-tandem mass spectrometry

Adult (Unit: nmol/day):

(Source: local reference interval was established from 94 normotensive and hypertensive Chinese subjects)

Children (Unit: nmol/mmol creatinine):

(Source: Modified from Ann Clin Biochem 2011; 48: 358 – 366)

Screening and diagnosis of phaeochromocytoma/paraganglioma.

Increased urinary metanephrine and normetanephrine excretions are found in patients with pheochromocytoma and tumors derived from neural crest cells (e.g. paraganglioma and neuroblastoma).