Isoimmunization after Massive Transfusion for Open Heart Surgery

One hundred consecutive patients subjected to open heart surgery received an average massive transfusion of 17 units. The group consisted of 43 males and 57 females; 75 were below 40 years of age. Routine testing for blood factors in the ABO, Rh and Kell systems were performed on all donors and recipients. The sera of all donors and recipients were screened for atypical antibodies. The number of recipients and their “average antigenic dose,” as well as the number of negative antibody screenings at postoperative visits, are tabulated. Nineteen rh‘ (C)‐negative patients received an average of 11.4 units of rh’ (C)‐positive blood. Thirty‐three rh“(E)‐negative patients, two hr’ (c)‐negative patients, three hr” (e)‐negative patients and 37 Kell‐negative patients received an average antigenic dose of 4.2, 8.5, 12.7 and 1.8 units, respectively. Two antibodies, anti‐rh'(E) and anti‐H, were attributed to isoimmunization. The authors conclude that the risk of detectable red cell isoimmunization by massive transfusion is probably no greater than that incurred by transfusion of a single unit.