In vitro factor VIII recovery during the delivery of ultra-pure factor VIII concentrate by continuous infusion
✍ Scribed by DiMichele, Donna M.; Lasak, Martin E.; Miller, Connie H.
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 397 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0361-8609
No coin nor oath required. For personal study only.
✦ Synopsis
Factor Vlll (FVIII) replacement by continuous infusion has been advocated as a costeffective method for maintaining stable plasma levels of FVlll in the hemophilia A patient during surgery or lifethreatening hemorrhage. Continuous delivery of monoclonal or recombinant FVlll concentrates to our pediatric patients using a traditional delivery system (dilution In normal saline of 2-10 U/ml Infused at a rate of 20 mVhr) has frequently yielded higher than expected factor usage to achieve desired levels and unexpected variability In plasma levels under presumed steady-state conditions. To determine If diminished In vltro FVlll recovery was responsible for these observations, a study of four ultrapure concentrates during 8 hr of in vltro continuous delivery was performed using four delivery systems. When reconstituted concentrate was added to normal sailne In polyvlnylchloride bags at a concentration of 10 U/ml (method IA), monoclonal products showed a stable recovery of 84-109% of time 0 levels. Recombinant product recovery dropped to 57-76% of time 0 levels before reapproximating the time 0 level at 2 hr. The addition of 10 mgl mi human albumin to the bags (method 16) did not improve recoveries. When reconstituted concentrate was delivered undiluted (method IIA), the early drop In recombinant recovery was eliminated; stable recovery of 78-117% of time 0 level was achieved with all products. In using method IA, a large discrepancy was seen between the actual time 0 recoveries and those expected based on vial assays, most striking for recombinant products (49-57% of expected). Method IIA allowed 7590% recovery; addition of 20 mglml albumin of reconstituted but undiluted concentrate (method 116) maximized recovery at 85-98% of expected. Q 1996 Wiley-Liss, Inc.