Often blood from children is drawn in the same big tubes used
for adults. I applaud parents, nurses, or phlebotomists acting
as advocates for children when large-volume blood draws are
ordered, to be sure that the amount of blood requested is
carefully considered. In general it is preferable to withdraw
the smallest amount of blood that will still allow the best
medical care for the child. One way to do this is to ask that
the blood be drawn in pediatric (not adult) tubes where
possible, using something we call micro-sampling techniques –
equipment designed to use the least amount of blood necessary
for each test. To parents, I suggest asking to be sure it is
truly necessary if someone suggests taking more than 1 ml of
blood per pound of your child’s weight (or a maximum of 30 ml
for larger children). Thirty ml is equivalent to 1 ounce.
GUIDELINES FOR PEDIATRIC BLOOD DRAWS I gave a general rule of
thumb I use as an outside limit for blood draws, because at
these levels of blood loss there can be measurable he