Assessment of a closed wash system developed for processing living donor femoral heads

NHS Blood and Transplant Tissue and Eye Services (TES) and Scottish National Blood Transfusion Services Tissues and Cells Directorate (TCD) currently bank whole, frozen femoral head bone from living donors who are undergoing primary hip replacement surgery. When required, the bone is issued to a surgeon still frozen on dry ice (- 79 °C). Consequently, the femoral head bone is not processed, is not sterilised and at the time of issue, it contains donor blood, bone marrow and associated cells. We have previously shown that, cut, shaped and washed bone from deceased donors can be processed to remove up to 99.9% of blood, bone marrow and associated cells (Eagle et al. 2015). However, cut and shaped bone is not suitable for some orthopaedic procedures and some orthopaedic surgeons do not wish to use irradiated bone; therefore in this report, a method has been developed in which whole femoral heads can be washed to remove donor blood and bone marrow components. Processing results in excess of 99% bone marrow component removal-soluble protein, haemoglobin and DNA; the procedure is performed inside a closed system, thereby eliminating the need for terminal sterilisation by irradiation. In addition, uniaxial testing demonstrated no difference in compressive strength between washed and unwashed bone. We suggest that this washed bone may be capable of improving incorporation after grafting without disturbing biomechanical properties of the graft.

Characterization of the surface physico-chemistry of plasticized PVC used in blood bag and infusion tubing

Commercial infusion tubing and blood storage devices (tubing, blood and platelets bags) made of plasticized PVC were analyzed by spectroscopic, chromatographic and microscopic techniques in order to identify and quantify the additives added to the polymer (lubricants, thermal stabilizers, plasticizers) and to put into evidence their blooming onto the surface of the devices. For all the samples, deposits were observed on the surface but with different kinds of morphologies. Ethylene bis amide lubricant and metallic stearate stabilizers were implicated in the formation of these layers. In contact with aqueous media, these insoluble deposits were damaged, suggesting a possible particulate contamination of the infused solutions.

Study of Hemolysis During Storage of Blood in the Blood Bank of a Tertiary Health Care Centre

The aim of RBC storage system in a blood bank is to counteract damage to the metabolic machinery and the membrane, to improve post-transfusion viability. In recent years, the need for strict control over the quality of blood has been emphasised. Such quality indicator includes extend of hemolysis and morphological changes of RBC during storage. This study was design to see extend of hemolysis and level of plasma lactate dehydrogenase (LDH) and plasma potassium, during processing and storage at different intervals under blood bank condition. Forty-six donors were selected and blood units were collected and stored under blood bank conditions. Mean plasma haemoglobin of stored blood was estimated by tetra methyl benzidine method (TMB) and percentage hemolysis was calculated on day 0, 1, 7, 21, 28, 35 and 42 days. Similarly plasma LDH and plasma potassium level was also assessed during storage. It was noted that free haemoglobin level and percentage hemolysis progressively increased with storage along with the level of LDH and potassium. However, extend of hemolysis did not exceed the permissible limit of 0.8% up to 42 days of storage. 15 blood bags which showed visual hemolysis on day 28 did not exceeded the threshold of 0.8% hemolysis, when interpreted by TMB method. It was concluded that TMB method is better than visual method for determination of hemolysis. The reduced hemolysis at this centre may be accounted for the use of additive solution SAGM (Saline, Adenine, Glucose, Mannitol) and DEHP (di-2-ethyl hexyl phthalate) as plasticizer in blood bags for storage.