A question about veins and blooddraws?

Question

Can anyone tell me if my phlebotomist was right in telling me to have other phlebotomists draw blood for my daughters CH (congenital hypothyroidism) in some other form than from a vein? Like a heelstick or prick? He said that it causes scar tissue in the vein and that it would make it harder to draw blood from the vein if used too often. My daughter has only one 'easy' vein to draw from, so I am concerned about this. Any help?

Answer 1

Veins can certainly get scarred and become harder with time, if they are used as a way of access to the bloodstream on a regular basis. And it is more likely so when they are used to inject substances than when they are used for drawing blood.
Other ways of access (like prick or other veins rather than the usual arm) can be suitable for certain type of analysis but not for others. It mainly depends on the amount of blood you need to draw, and the age of the person/child.
Finger prick, for example, is the easiest way to obtain blood if you just need to check the levels of sugars, and it can be repeated daily with no major problems.
You don't specify how often your daughter needs her blood to be taken, and how old she is.
In general, thinking about hypothyroidism, in the long term, once the replacement therapy is in place at the correct dosage and your daughter reaches a certain age, her thyroid hormones probably won't need to be checked more than once every two months. Again, this will depend on the characteristics of the hypothyroidism and what medications she is on though.
Another considerarion that I feel like making is that it is very very unlikely that any person, even a young child, will have only one accessible vein. A lot relies on the expertise of the person who is drawing the blood. In my experience, I have seen paediatricians drawing a considerable amount of blood (5-10mls) from tiny toddlers gaining access from an almost invisible vein in the hand. It is not easy, but it can be done, and it is not much worse for the child than a "normal" arm access.
So, I think you shouldn't worry too much about this. As I said, you don't give all the information, but it is probable that your daughter won't need, in the long term at least, blood draws frequently enough to seriously affect her vein. If alternatives (like prick) are suitlable, they are certainly worth considering. But, also, it is likely that with time, maybe with growth, or in the hands of a more expert professional, it will be possible to access more than one vein (it is almost always possible).
Best of luck to you and your daughter.

Answer 2

This would depend a little on your daughter's age and the frequency of blood tests.

In most cases in Australia, infants can have certain blood tests done by heel prick. For older children, most blood tests are done in the usual way - drawing the blood from the arm.

However, thyroid function tests are something your daughter may well need on a monthly basis or a couple of times per year. It might not be necessary to "spare" the vein and you daughter might well be able to have blood taken in the usual manner.