Читать книгу Transfusion Medicine - Jeffrey McCullough - Страница 131

Washing is indicated for severe allergic reactions and for removal of potassium in large‐volume transfusion in pediatrics. The definition of washed red cells is rather vague. These are the red cells remaining after washing with a solution that will remove almost all of the plasma [24]. Thus, the requirements for this component do not specify the nature of the washing solution or the exact composition of the final component. Red cells can be washed by adding saline to the red cells in an ordinary bag, centrifuging them and removing the supernatant, or by using semiautomated washing devices, such as those used for deglycerolization [48–50]. Depending on the solution and technique used, the washed red cells may have a variable content of leukocytes and platelets. There is usually some red cell loss during the washing step, and the resulting red cell unit may contain a smaller dose of red cells than a standard unit. In general, the characteristics of washed red cells are the removal of approximately 85% of the leukocytes, loss of about 15% of the red cells, and loss of more than 99% of the original plasma [48–50]. Because the washing usually involves entering the storage container, the washed red cells have a storage period of 24 hours at 1–6°C.