fbpx

COVID-19 update:  Our hospital is still fully open for appointments and admissions, however visitors are not permitted.

Plasma catecholamine/metanephrine blood samples

Blood samples will be taken from the arm using a small butterfly needle. Catecholamines / Metanephrines are a group of hormones (adrenaline, noradrenaline and dopamine) which circulate in the blood and help regulate blood pressure and heart rate. The levels of catecholamines/ Metanephrines in the blood changes with posture (the levels increase from lying to standing). Blood samples are usually taken whilst lying, following a 10 minute rest period, and whilst you are on the tilt table in the standing position.

On some occasions, a spot catecholamine/ Metanephrines blood sample is taken during testing. This usually occurs if the clinical autonomic scientist observes a sudden marked increase in blood pressure and / or heart rate which correlates to certain symptoms. This test is performed to determine whether there are any sudden increases in the catecholamine levels, which could explain the symptoms.

How do I prepare for the test?

Please do not eat for 4 hours prior to testing. You may drink water only in the lead up to the test. Please do not drink alcohol & do not carry out heavy exercise 12 hours prior to your appointment.

For the blood tests, please avoid the following food and drink items for 48 hours prior to testing: caffeine (coffee, tea, coca cola etc) bananas, chocolate, cocoa, citrus fruits & vanilla.

Please wear loose fitting clothing on the day of your appointment. We recommend a loose fitting T-shirt and loose fitting trousers or shorts.

If you require emla cream when having blood taken, you will need to obtain this from your GP or a doctor prior to your appointment. Emla cream needs to be prescribed by a doctor and we do not have a supply available in the unit / hospital. Please apply the emla cream to the antecubital fossa area on both arms 30 minutes prior to your appointment. Please refer to the red triangle below. Please bring extra emla cream to your appointment.

How will I feel during the test?

This is a very routine method for taking blood.

You may feel some brief discomfort as the needle is place in the arm. On occasions, some people experience dizziness and light headedness during the blood test(s). Please inform the clinical autonomic scientist if you experience these symptoms during testing.

What are the risks?

This is a very routine and minimally invasive test. But, as with any medical procedure, it does carry some risks. You may experience slight bruising at the site where the needle entered the skin. This should disappear within a few days.

Blood should not be taken from the same arm in which an arteriovenous fistula (such as used in hemodialysis) is present, or where lymphadema exists. Furthermore, caution should be used if you are at high risk for developing lymphedema (such as after lymph node dissection for treatment of breast cancer).

What happens if I have questions?

If you have any questions or concerns, please ask the clinical autonomic scientist before signing the consent form for the procedure. If you are not happy to proceed with the test, please inform a member of the testing team. Even after signing the consent form, you may withdraw your consent at any time during the test.

When will I get my results from the test?

We are unable to provide results of the test on the day of your appointment. All results will be sent to Professor Mathias. You will need to arrange a follow up appointment with Professor Mathias to discuss the results of the test(s). Please email autonomic.consulting@gmail.com to arrange the appointment. Please note that the results of the blood test(s) can take 5 – 10 working days.

Close up of an arm with a plaster having just had a blood test

Pathology Department

The Pathology Unit has full unconditional CPA accreditation The Laboratory provides a 24...

A patient speaking to a receptionist

Patient information

Our Hospital is renowned for providing exemplary levels of care across more than 90 services. From orthopaedics, to urology, ENT, as well as a private GP practice and our urgent care centre, Casualty First, our services are led by some of London’s leading Consultants. For more information, and to find a service suitable for your care, find out more about the services that we offer.

Make an enquiry

If you have any questions relating to treatment options or pricing information then get in touch with us by filling out one of our contact boxes or giving us a call on 020 7806 4022.

Our Appointments Team have a dedicated and caring approach to finding you the earliest appointment possible with the best specialist.

 If you are self-paying you don’t need a referral from your GP for a consultation. You can simply refer yourself* and book an appointment.

If you have medical insurance (e.g. Bupa, Axa PPP, Aviva), you will need to contact your insurer to get authorisation for any treatment and, in most cases, you will require a referral letter from your GP.

If you do not have a GP, then we have an in-house private GP practice that you can use. Alternatively we can suggest the most appropriate course of action for you to take, given your location and individual circumstance.

*Please note – for investigations such as X-rays and MRI’s a referral will be required. However, we may be able to arrange this for you through our on-site private GP.

    Make an enquiry

    Latest articles

    The latest news, insights and views from St John and Elizabeth Hospital.

    Find out what we’re doing to keep you safe, read expert articles and interviews with our leading specialist Consultants, learn more about common conditions and get your questions answered.

    Remember to subscribe to our monthly newsletter to get the latest news sent straight to your inbox.

    a close up of above the pelvic region - a blog post about urology

    23rd July 2021

    What does a urologist do on the first visit?

    We look at the complex world of urology and what to expect on the first visit to a urologist.

    dr showing how to examine breasts for lumps

    16th July 2021

    How regular screenings at a breast clinic can keep you healthy

    Having screenings at a breast clinic can put your mind at rest or allow you to take early action if something abnormal is found.

    private surgeons performing a hernia operation

    09th July 2021

    Scheduled for a hernia operation? Here’s what to expect

    We look at hernias and the different types that can occur, what kind of symptoms might tell you you have a hernia and what to expect if you’re scheduled to have a hernia operation.

    A smiling nurse

    02nd July 2021

    How much does a cervical screening cost?

    Wondering how much a cervical screening costs? We examine this important procedure and…

    a close up of female skin side shoulder view

    18th June 2021

    Checking your skin at a private dermatology clinic

    We examine the functions of the skin, what can go wrong and when…

    a doctor talking to a patient at a private urgent care centre in london

    04th June 2021

    A private urgent care centre for when you need immediate attention

    There’s no need to wait around when you opt for a private urgent…

    A patient waiting at London Urology

    28th May 2021

    The 3 most common prostate problems you need to know about

    One in five men will experience prostate problems at some point in their…

    Fibroscan at The Gi Unit

    14th May 2021

    What is a Fibroscan: Five facts you may not know

    A Fibroscan is a simple, painless and non-invasive procedure used to accurately assess…

    International Nurses Day blog banner

    11th May 2021

    International Nurses Day 2021 at St John and St Elizabeth Hospital

    This year’s theme of International Nurses Day is: “A Voice to Lead –…

    Close up of woman exercising on gym machine

    23rd April 2021

    Mr Dimitrios Tsekes: How to avoid a bicep injury in the gym, and how to treat a bicep tendon tear

    Mr Dimitrios Tsekes, a leading orthopaedic and upper-limb surgeon at our Shoulder Unit,…

    12th March 2021

    Patient safety awareness: our pledge

    Patient safety is at the heart of St John & St Elizabeth Hospital’s…

    03rd March 2021

    Ask the Expert: Cataracts

    Cataracts are a common issue affecting older adults, where cloudy patches form on…