Normothermia, hypothermia, and postoperative bleeding.

GIL, OSCAR; CATALA, JUAN.; LUNA, DANIEL R.

The Annals of thoracic surgery

The Society ot Thoracic Surgeons

Año: 1995

0003-4975

We read with interest the article "Normothermia Versus HypothermiaDuring Cardiopulmonary Bypass: A Randomized, ControlledTrial" by T6nz and associates [1]. This excellent articlesuggests a significant influence of cardiopulmonary bypasstemperature and perfusion management on postoperative hemodynamicsand blood loss.We agree with T6nz and associates that increased bleedingtendency after CBP is most often due to an acquired plateletdysfunction. There is a great variability of transfusion practice incoronary artery bypass grafting [2], but according to the "Guidelinesfor Transfusion Support in Patients Undergoing CoronaryArtery Bypass Grafting" [3] the therapy in postoperative bleedingmanagement should be directed toward correcting specificdisorders. In other words, a normal platelet count should notpreclude platelet transfusion in the setting of excesive bleedingif a qualitative platelet defect is suspected [3]. In this controlled trial, 50% of patients after hypothermiccardiopulmonary bypass needed fresh frozen plasma to counteractan increasing bleeding tendency, as compared with nonein the warm group. T6nz and associates presumed that areversible platelet dysfunction induced by hypothermia wasresponsible for the increasing bleeding tendency in the coldgroup, but none of the patients received platelet transfusions.We would ask Ttinz and associates the following questions:Why was fresh frozen plasma transfused instead of platelets?Were there any differences in the prothrombin time before freshfrozen plasma transfusion? Were there any differences in thepartial thromboplastin time between the two groups? Did any ofthe patients receive additional doses of protamine after the endof the cardiopulmonary bypass [4]?