Education Resource from the Society for Endocrinology
Paediatric Endocrine Nurse, Southampton
Endocrine Nurses Training Course 10-12
St Aidan's College, University of Durham, Windmill Hill, Durham DH1 3LJ
The Pituitary Gland lies at the base of the brain. It makes several hormones (chemical messengers) which act on other parts of the body. One of these hormones is called Growth Hormone, which as its name suggests is needed for normal growth during childhood.
In children and adults, Growth Hormone levels vary a lot throughout the day and night, in response to exercise, stress, sleep and other hormonal changes. Most of the time during the day, levels of Growth Hormone in the blood are very low and are difficult to measure. This means it is necessary to stimulate the release of Growth Hormone to accurately assess how much your child is able to produce.
At the start of the test, your child will be given a tablet called Clonidine, which indirectly causes the body to release Growth Hormone. The amount of Growth Hormone your child produces can then be measured by taking regular small blood samples throughout the test.
Your child should have nothing to eat or drink after midnight on the night
before his test, and will not be able to eat during the test (3-4 hours).He
can drink water if thirsty. He will be able to eat and drink again normally
as soon as the test is finished.
Soon after admission the nurse or doctor will insert a very small plastic tube (called a cannula) into your child’s arm, or the back of their hand. The cannula will be used to take small blood samples throughout the test.
While it is in place the cannula does not hurt but your child will have a splint and bandage put on his arm to keep it straight and some find this a little uncomfortable. To help stop the cannula blocking an infusion of salt water is started (a’ drip’).
Soon after this we will give your child the Clonidine. This comes as tablets that can be swallowed whole or crushed.
We will take blood samples from the cannula every 30 minutes for the next 2-3 hours. The cannula is removed shortly before your child is ready to go home.
Clonidine will lower your child’s blood pressure and he may also experience drowsiness, dizzyness and dry mouth. It is important your child rests on his bed during the test as he may be very unsteady on his feet. We will be observing your child closely and recording his blood pressure regularly. As his blood pressure drops we may tilt the bed so your child is lying head downwards – this is quite usual during this test.
We will continue to observe your child closely. He should be encouraged to
sit up slowly and eat his lunch. We can order something from the kitchen, you
can bring in a packed lunch or buy him something from the shop/café.
We would strongly advise that you do not offer food from the Burger King, as
this is likely to make him sick.
When your child has eaten his meal he will be assessed by a senior nurse and the ‘drip’ removed. Most children have recovered within 3 hours of the test finishing. Occasionally
this takes longer and rarely a child may need to stay in hospital overnight.
Some children may feel ‘wobbly’ for the rest of the day. Your child should spend the rest of the day quietly and not participate in any sporting activities or operate machinery. He should be encouraged to eat well at teatime. He should be back to normal by the following day.
Are usually available in 2 weeks and you can telephone the Endocrine Nurse for them. You can then discuss any further tests or treatment recommended with the team at your next clinic appointment.
Pauline Musson. Paediatric Endocrine Nurse. 18th December 2001.
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The opinions expressed in this paper are those of the speaker and do not necessarily reflect the views of the Society