Relação entre as técnicas de coleta de sangue de cordão umbilical e placentário de células nucleadas: uma revisão integrativa

Abstract

MORAES, C. M. G. Relationship between the techniques of collecting umbilical cord blood and placental and total nucleated cells: an integrative review. Monograph. 40f. 2012. The first transplantation of hematopoietic stem cells from umbilical cord occurred in 1988. Since then, stem cells from umbilical cord are being increasingly used and studied. Its use has several advantages such as availability, lower restriction for compatibility, lower risk of transmission of infectious diseases and the development of rejection, easy transport and absence of risks in the donation process. However cord blood is associated with higher risks of failure grafting in immune and hematopoietic reconstitution in the recipient. Collection of umbilical cord blood for storage in banks, is via the umbilical vein puncture with the placenta in utero or after placental delivery, and can be validated by elements such as volume, number of nucleated cells, progenitor cells, cell viability and bacterial contamination. Aiming to identify in literature with which technique is obtained the highest number of total nucleated cells, as theoretical reference the evidence-based and methodology the integrative review, it was conducted a search of articles in BVS and the databases CINAHL, SCOPUS, WEB OF SCIENCE AND PUBMED. It merely seeks articles, studies with humans, in English, Portuguese and Spanish from 2001 to 2012. We used one indexed descriptor and two keywords: Cell Count, Umbilical cord blood and collection technique. After reading, 14 articles were selected. 92% were published in English, 57% developed in cord blood banks and 57% published in the journal Transfusion. According to the classification of levels of evidence proposed by Melnyk and Fineout-Overholt (2005 apud POLIT; BECK, 2011), the articles were classified at levels IV e VI. When it was related technical delivery and the collection technique 35% of the articles analyzed, collected samples for technical intra uterus after vaginal delivery, 21% extra for technical uterus by vaginal delivery, 42% collected by the technique extra uterus by cesarean section and 21% technique in intra uterine cesarean section. Twelve items evaluated the relationship between the type of collection and getting better results with the number of cells, in those 50% recommend collection technique for intra uterine, getting better cellularity. Among the reasons mentioned in studies as possible for the differences found between the results obtained by the techniques of collection, would be bleeding and clots in the placenta afterbirth and the time between afterbirth and the collection bag. We consider some important factors that may affect the results of this work: such as dropping bags with low cellularity, cited in the studies, whose results have not been presented, no comparison between TNC count techniques to provide the results and the no evaluation of obstetric factors that studies report that may interfere with cellularity. We conclude that further studies are needed to determine the best procedures and technique for the collection of umbilical cord blood. The use of umbilical and placental cord blood is a relatively new procedure, and services are increasing in number, including in Brazil, opening for nurses, professional who makes this procedure, a field for work and research. As a license professional for this activity, it is natural and necessary that its seeks legitimize knowledge and improve their practice, and consequently contribute to the improvement and success of the transplants using umbilical cord blood.