Urinary metanephrines

Investigation Protocol

Indication

Urinary metanephrines are the first line screen for phaeochromocytoma.

Preparation

Patients may eat and drink normally prior to test. Written instructions must be given to the patient prior to performing this test to ensure that both 24 hour collections are performed accurately. Two special 24 hour collection bottles containing acid preservative should be provided to the patient in advance. Caffeine and cigarettes should be avoided for four hours, and all over the counter medicines should be avoided for 48 hours before the test, as paracetamol can cross react with assays and cough medicines may contain sympathomimetics.

Procedure

Patients are informed to choose two convenient days to perform their urinary collections. The two days need not necessarily be consecutive.  

Patients need to be advised that the collection bottles contain a preservative and so should not pass urine directly into them.

Patients are advised to empty their bladder into the toilet normally on waking on the morning that they start a collection and note the time. From that time onwards, all urine passed that day should be collected into a plain collection bottle. All urine passed during that night should also be collected.

The patient should set an alarm if necessary to wake them by the same time the following morning. That morning, the patient should empty their bladder and collect this as the final sample into the same bottle as from the previous day. This means that they start and finish the collection with an empty bladder at the same time of day.

The test should then be repeated on a second day and both collections brought in together for analysis.

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Patient information sheet

Urinary metanephrines

Your doctor has asked us to coordinate a urine test to measure some very specialised hormones, which are produced in glands called the adrenals.

It is very important that the test is completed on two days, and that every time you pass urine it is all collected as this will affect the results of your test. However, since the bottles contain a preservative that may sting, we recommend that all urine is collected into a separate container and then poured into the bottle.

First identify a day which is suitable: it is probably easiest if there is a day you are not planning to go out on to perform this test. You will need to repeat the test on two whole days, but they need not be consecutive if this is less convenient. For example, you might find it easier to perform the tests on two sundays in a row.

Please take all your usual medication and you may also eat and drink as normal on the day of this test. However, caffeine such as coffee, tea and cola, and cigarettes should be avoided throughout the test. All over the counter medicines should also be avoided for 48 hours before, and during the test, as paracetamol and various decongestant remedies interfere with these tests.

The easiest way to start the test is to empty your bladder into the toilet normally when you wake up, on the morning that you start a collection, and note the time.  From that time onwards, all urine passed that day should be collected into the bottle. All urine passed during that night should also be collected.

We recommend that you set an alarm if necessary to wake you up by the same time the following morning.  That morning, you should empty their bladder but collect this as the final sample into the same bottle as from the previous day. This means that you start and finish the collection with an empty bladder at the same time the next day.

The test should then be repeated on a second day and both collections may be brought in together for analysis.

If you have any queries about the test, please contact: 

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