tailieunhanh - Hanbook of pediatric transfusion medicine - part 10

Bên ngoài (mua lại) rối loạn tế bào màu đỏ, tương phản nội tại (di truyền) rối loạn, thường ảnh hưởng đến một số lượng nhỏ hơn tổng số tuần hoàn những tế bào màu đỏ nhưng vẫn có thể được kết hợp với sequellae sinh lý quan trọng. | 30. Therapeutic Cytapheresis 359 Extrinsic Acquired Red Cell Disorders Extrinsic acquired red cell disorders in contrast to intrinsic inherited disorders usually affect a smaller number of the total circulating red cells but still may be associated with significant physiological sequellae. Red cell exchange has been used to treat patients with protozoal infection poisoning and incompatible transfusion by removing infected impaired or foreign red cells and replacing them with compatible red cells from healthy donors Phillips et al. 1990 Weir et al. 2000 Evenson et al. 1998 . Erythrocytapheresis can be a lifesaving measure in patients with glucose-6-phosphate dehydrogenase deficiency following exposure to significant oxidant stress that causes refractory methemoglobinemia Golden and Weinstein 1998 . Malaria Cerebral malaria is a life-threatening complication of Plasmodium falciparum infection. Although controlled comparative trials have not been performed case studies suggest red cell exchange in conjunction with antimalarial regimens results in more rapid reduction in peripheral parasite load and clinical improvement than pharmacotherapy alone Phillips et al. 1990 . Because the degree of parasitemia correlates with mortality red cell exchange transfusion has been recommended when parasites are detected in more than 10 to 20 of the patient s red cells Grima 2000 Phillips et al. 1990 Weir et al. 2000 . Red cell exchange has also been recommended for other patients regardless of parasite burden with severe complications of falciparum malaria such as encephalopathy disseminated intravascular coagulation renal failure and adult respiratory distress syndrome. Due to the paucity of data more specific recommendations regarding the extent of treatment are not possible. The minimum effective volume of red cell exchange in treating complications of falciparum malaria has not been determined a little as one-half and as much as two blood volumes have been exchanged in published