Control of the postirradiation hemorrhagic state by platelet transfusions.

Lacassagne amnd Lavedann,3 amid bleedinng unto the tissues was clearly inndicated by Shouse et al.’ The parallel betweemn the postirradiation hemorrhagic temndemncy and the decrease inn circulating platelets has beenn confirmed by other w-orkers,5m#{176} and the conncept of “hyperheparinnemia” as a major cause of radiation hemorrhage has 1)eemn abanndonned.6 A new impetus to studies of the role of platelet deficiemicy inn radiationn imnjury was givenn by the work of Cronnkite et al.,8 11, 12 w’ho demonnstrated that daily injectionis of platelet suspensions begumn before thrombocytopemnia developed prevennted the hemorrhagic phase as seenn at autopsy. This study describes the extennt to which sinngle platelet innjectiomns diminnish the hemorrhagic tenndenncy of irradiated dogs annd rats as indicated by erythrocyte coumnts inn the lymph. Inn the experimemnts of Cronkite et al., irradiated platelettrannsfused animals were conntrasted with uintreated annimals, h113 amid thus onnly a clinnical comparisonn of the platelet effect was possible. The lymph fistula annimals used inn this study, however, served to a large extemnt as their own conntrols, amid the platelet effect could thereby be expressed quanntitatively with respect to the degree of the hemorrhagic state before treatmennt annd improvement inn relation to time after treatment.