Pediatric large volume peripheral blood progenitor cell collections from patients under 25 kg: a primer.
Academic Article
Overview
abstract
Collection of peripheral blood progenitor cells from small pediatric patients provides many social and technical challenges not faced when collecting from adult patients. This paper provides a single institutions experience with 85 collections from 14 patients less than 25 kg of weight over a 2 year period. Specific challenges include obtaining venous access, anticoagulation, volume shifts, and obtaining patient cooperation. A systematic analysis of options for access, alternative modes of anticoagulation, and the effect of large ratios of extra-corporeal volume to patient's blood volume are discussed. Access uniformly required central venous catheters (CVC) ranging from 7-10 Fr. Anticoagulation included systemic heparinization titrating dose by activated clotting time in all cases and combined with citrate at a ratio of 1:25-1:30 in most cases. Collections were performed on a COBE Spectra, after priming with leukoreduced irradiated red cells and omitting both the initial 120cc diversion and rinse back of red cells at the end. Social challenges include issues of assent and ability to distract patients for the duration of a prolonged collection. Progenitor yields from collections from 14 patients were quantitated by CD34+ assay in all cases and CFU-GM in ten of 14 patients. A median of 4.5 x 10(6)/kg CD34+ cells were obtained for each collection. Complications, including those related to catheter access, are enumerated. In summary, large volume peripheral blood progenitor collection can be safely and efficaciously performed in small pediatric patients.
