Red blood cells and plasma harvested from cord blood of preterm and term infants: Sterility and indicators of quality for early retransfusion
Objective: Even though red blood cells from cord blood (CB) have been investigated for many years for the purpose of autologous retransfusion to newborns this technique is still far from clinical routine. In severely ill neonates fresh frozen plasma from donors is frequently transfused for volume expansion or as a source of coagulation factors but autologous plasma transfusion has not been described.
Methods: We investigated 35 CB preparations of preterm and term newborns for sterility and fast provision of either red blood cell concentrate (RBC) or plasma with respect to quality of both components and time needed for bacterial testing. CBs and 34 control RBCs from regular blood donors were collected in citrate-phosphate-dextrose solution (CPD). RBCs and plasma were prepared in sodium-adenine-glucose-mannitol (SAGM). Swabs were taken from the placenta for cultivation of bacteria. Quality of stored blood was assessed in RBCs on day 0, 3, 8, 14 and 42, respectively, and tests for activated coagulation were done in thawed plasma.
Results: CB harvesting started within 30 minutes after umbilical cord clamping. A mean CB volume of 50.6 mL (range 19.6 mL to 90.6 mL) was collected. None of the bacteria detected in the placenta smear could be detected in the collected CBs. Mean Hct in the RBC was 53 ± 7%. Glucose, pH, ATP and 2,3-DPG decreased over time, while lactate, potassium, hematocrit and hemolysis increased. Sterility of CBs was verified within 72 hours. Prothrombin fragment 1 + 2 (F1 + 2; n = 34) was elevated (3.9 ± 2.5 nmol/L), and high levels of thrombin-antithrombin complexes (TAT) were detected also in the majority of newborns' plasma (>61 μg/L; n = 31).
Discussion: Suitability of RBCs from CB must be restricted to 14 days, mainly because of a decreasing pH. Probably, by adding CPD solution at an amount appropriate for the actual volume of CB it will be possible to extend the storage time. However, retransfusion of plasma harvested from CB seems imposssible, due to the activated coagulation process.