I am a nurse that does growth hormone testing on children and adults. We use a regular angiocath that we insert to draw baseline labs and then give medication over 30 minutes and continue to draw blood from the line every 30 minutes until the 150 minute mark. I am having trouble getting blood back through the catheter after giving the infusion. The IV flushes without a problem, the fluids are opening the catheter, but it seems to be collapsing when pulling back. I can't seem to find a catheter out there that will work. Therefore we end up doing venipunctures every 30 minutes in order to finish the test. That is fine on an adult but sometimes these children are 2 years old. Does anyone know of a catheter made for serial blood draws? The IV would only be in for approximently 3 hours total.