Metanephrines, urine

Sample type

24-hour urine

Uses

1-Confirmation of elevated plasma catecholamine levels.

2 - Diagnosis of pheochromocytoma and paraganglioma.

3-Diagnosis and follow-up of patients with neuroblastoma and related tumors.

4-First line of test in patients with lower suspicion of pheochromocytoma (patients with resistant hypertension, hyper adrenergic spells, incidentally discovered adrenal mass that does not have imaging characteristics consistent with pheochromocytoma).

Precautions

1-Complete 24-hour urine collections are preferred, especially for patients with episodic hypertension; ideally the collection should begin at the onset of a spell

2- No caffeine before or during collection. Monamine oxidase inhibitors should be discontinued at least one week prior to beginning collection

24-hour urine sample collection instructions

• On day 1, urinate into the toilet when you get up in the morning.

• Afterward, collect all urine in a special container for the next 24 hours.

• On day 2, urinate into the container when you get up in the morning.

• Cap the container. Keep it in the refrigerator or a cool place during the collection period.

• Label the container with your name, the date, the time of completion, and return it as instructed

Interferring factor

1-No caffeine intake should occur before or during collection. MAO inhibitors should be discontinued at least 1 week prior to beginning collection

2-Methylglucamine in x-ray contrast medium can cause false-negative test results.

3-False positives can be caused by stress and drugs, which includes amphetamines and amphetamine-like compounds, appetite suppressants, bromocriptine, buspirone, caffeine, carbidopa–levodopa (Sinemet), clonidine, dexamethasone, diuretics, methyldopa(Aldomet), nose drops, propafenone (Rythmol), tricyclic antidepressants, and vasodilators.

The effects of some drugs on catecholamine metabolite results may not be predictable.

Pre analytical erorr

1-Caffeine affect the result

2- some drugs affect the result

3-3-If the sample was not collected with the correct instructions ,it will affect the result

Corrective action

1- asking the patient to stop drinking Caffe before collection.

2-taking medical history and medications that may affect the result

3-The patient must be given the instructions that the sample must be

collected, and before taking the sample make sure that he follows these instructions

Post-analytical errors

1-Writing a wrong result or wrong name in the report

2-report were sent to incorrect patient

3-If the patient’s gender wrong in the report, and therefore I wrote the reference range wrong.

The corrective action

1- If the report is not delivered to the patient and this error is discovered the correct result or the correct name must be written, but if the report is delivered to the patient must communicate with him and tell him that an error has occurred and replace with the correct report.

2- 2-Communicate with patient ,apologizing for the error, and providing him with the correct report.

3- If the report is not delivered to the patient and this error is discovered the correct result must be written, but if the report is delivered to the patient must communicate with the patient, and apologize to him tell him that an error has occurred and replace with the correct report. And next time be carful to write the correct gender and the correct reference range.

Reference range

mcg/24-hour وحده

Metanephrine, U, 24 hr

(mcg/24-hour)

Age

Male

Female

0 to 8 y

30 – 150

32 – 123

9 to 12 y

54 – 209

44 – 161

13 to 17 y

56 – 236

44 – 161

<17 y

58 – 276

36 – 209