tailieunhanh - Mollison’s Blood Transfusion in Clinical Medicine - part 10

Trẻ cân nặng từ 28 đến 50 kg có thể được chảy máu của 250 ml vào paedipaks, có chứa 35 ml CPD-A1. Nếu không có sẵn, các gói này là một gói kích thước tiêu chuẩn có thể được sử dụng với một gói vệ tinh kèm theo để chống đông máu quá mức có thể được loại bỏ trong khi duy trì một hệ thống khép kín. Số lượng máu được thực hiện không được vượt quá 12% | CHAPTER 18 collection of blood from children is difficult. Children weighing between 28 and 50 kg can be bled of 250 ml into paedipaks which contain 35 ml of CPD-A1. If these packs are not available a standard-sized pack can be used with a satellite pack attached so that excess anticoagulant can be removed while retaining a closed system. The amount of blood to be taken should not exceed 12 of the blood volume and is calculated as weight kg 50 X 450 ml and the volume of anticoagulant to be used as volume of donation ml 450 X 63 ml. It is prudent to perform the same tests on autologous blood as on blood donated by routine blood donors. The main reasons for this recommendation are 1 to address the possibility that a mistake in identification may be made leading to the transfusion of blood of the wrong ABO group or of blood contaminated with an infectious agent and 2 to discover whether the patient is already infected with a virus that he or she fears might be acquired by transfusion with allogeneic blood. UK collection and transfusion centres will not store autologous units found positive for HBsAg or for anti-HIV -HCV or -HTLV. In any case autologous donations should be clearly labelled and stored separately from routine blood donations Lee et al. 1993 . Although the use of platelets is rarely indicated in elective surgery except perhaps in complicated cardiac or vascular surgery the collection of platelets with cell separators taken either 1-2 days or immediately before surgery has been reported Giordano et al. 1988 1989 . The practice of collecting blood from healthy subjects for long-term frozen storage in case they should require future transfusion is expensive wasteful and impractical. On the other hand long-term storage of autologous blood is indicated for 1 subjects with rare blood groups or with multiple red cell antibodies for whom compatible blood may be difficult to find and 2 those rare patients who have had more than one unexplained haemolytic .