Because blood clots frequently occur within the lumens of paediatric haemodialysis central-venous lines, they must be routinely aspirated before use to prevent pulmonary emboli. The smaller diameter lines used for parenteral nutrition and cancer chemotherapy are seldom managed this way.
We looked for clots when children undergoing cancer chemotherapy had their heparin-locked central lines accessed, and compared them to children on haemodialysis. Haemodialysis patients had clots aspirated on 83% of occasions, and each child had clots at least once. Clots also occurred in the smaller lines, but they were less frequent (64%, P=0.01), and had a lower median weight than in dialysis lines (14.1 vs 25.2 mg, P=0.01).
When small diameter central lines are used without initial aspiration, small pulmonary emboli are likely to occur, but are unlikely to be individually clinically important. Daily use, as with long-term parenteral nutrition, might result in over 3 g of clot being embolised annually. Consideration should be given to aspirating all paediatric central lines before use.
- central venous line
- pulmonary embolus