AN OVERVIEW OF THERAPEUTIC APHERESIS IN PEDIATRICS

Therapeutic apheresis in pediatrics requires selected modifications du e to the child's smaller size, blood volume, and developmental age. Re d blood cell priming is used to prevent dilution of the child's hemato crit from the normal saline prime. Continuous flow cell separators mai ntain isovolemia. Discontinuous flow machines cause alterations in the blood volume which may be poorly tolerated by small and critically il l children. Whole blood volumes are calculated on 100 cc/kg for newbor ns and 70 cc/kg for toddlers and children. Although peripheral access may be used in older children, the majority of pediatric patients requ ire central venous lines preferably the stiffer apheresis or dialysis double lumen catheters. Anticoagulants include heparin, anticoagulant citrate dextrose (ACD), or a combination of both. The heparin dose is titrated to achieve activated clotting times of 180-220 seconds. Child ren are more sensitive to the hypocalcaemic effects of ACD especially if citrated replacement products such as fresh frozen plasma are used. Prevention or treatment of low ionized calcium levels may include dec reased citrate rates, calcium addition to 5% albumin replacement, calc ium gluconate infusions, intravenous boluses of calcium chloride, or a change in anticoagulant. Apheresis risks can be reduced through adequ ate monitoring and preventive measures. The most commonly performed tr eatments are plasma exchanges and peripheral blood stem cell collectio ns. Diversional activities appropriate for the child's developmental a ge are provided to allay anxiety, to divert attention, and to elicit c ooperation. In conclusion, size and clinical condition are not exclusi onary criteria for apheresis. (C) 1997 Wiley-Liss, Inc.