Immunoprophylaxis using intravenous Rh immune globulin should be standard practice when selected D-negative patients are transfused with D-positive random donor platelets.

A 67-year-old female developed excessive bleeding and thrombocytopenia following cardiovascular surgery. Her blood type was group A, D-. The only platelet products available in the transfusion service were random donor platelet concentrates from D+ donors. She was transfused with a pool of 6 D+ random donor platelet concentrates. Anti-D undetected in her pretransfusion serum by solid-phase antibody screen was present 11 days later. Retrospectively, the patient provided a history of having two pregnancies more than 40 years ago, prior to the availability of immunoprophylaxis by Rh immune globulin (RhIG). Although studies have shown that as many as 19 percent of D- people may develop anti-D following transfusion of platelets from D+ donors, there is no specific standard requiring immunoprophylaxis with RhIG to prevent Rh alloimmunization after transfusion of random donor platelet concentrates from D+ donors. In contrast, vigorous efforts are routine for preventing Rh alloimmunization in D- patients requiring red cell transfusions or D- females during pregnancy or after delivery of D+ newborns. The absence of a comparable practice standard for platelet transfusions is based, in part, on concern that intramuscular injections of conventional RhIG may cause local hemorrhage in thrombocytopenic persons. The recent availability of a Food and Drug Administration-approved preparation of intravenous RhIG makes Rh immunoprophylaxis in thrombocytopenic patients safe and practical. We recommend that intravenous RhIG be considered if it is necessary to transfuse random donor platelet concentrates from D+ donors to D- recipients. As a minimal standard, intravenous RhIG should be administered to all D- females of childbearing age who are recipients of pools of random donor platelet concentrates from D+ donors.

Rapid thawing of fresh frozen plasma in two-liter bags.

The authors hypothesized that plasma could be rapidly thawed in two-liter Transfer Pack Units, because of their greater surface area (993 cm2) compared to standard satellite bags (348 cm2) of Blood Pack Units (both from Fenwal, Baxter Healthcare Corp, Deerfield, IL). Five units of FFP were prepared in each bag. The Sterile Connection Device (DuPont, Wilmington, DE) was used to transfer plasma from the satellite to transfer pack units, and these were put in metal canisters before all units were frozen at -65 degrees C. Thawing time was 4.8 +/- 1.3 (SD) minutes and 15 +/- 3.2 (SD) min. for units prepared in modified and standard methods respectively (t = 6.33, P less than .01). The thermal rate constants were calculated as 0.0034 and 0.0033 for the two methods. The finding of similar values substantiate the theory that thawing time is related to the volume to surface area ratio.