Diluíçåo de concentrado de hemácias em soluçåo fisiológica a 70ºC nåo causa hemólise / Dilution of red blood cell concenntrate with normal sline at 70ºC does not result in hemolysis

RESUMO

Heating of cold stored blood before transfusion is required to avoid hypothermia during massive transfusion. The objective of this study was to verify the efficacy and safety of a new technique of heating red blood cell concentrates (RBCC) through dilution in normal saline (NS) at 70ºC. In glass tubes, 5 ml of RBCC at ambient temperature or refrigerated were diluted in 5 ml NS at three different temperatures ambient, 70ºC or 95ºC. The resulting temperature was recorded. Free hemoglobin (Hb) and plasma potassium (K+) were determined and compared among the different dilutions. The dilution of refrigerated RBCC in NS at ambient temperature was considered as control, with a resulting temperature of 18.5 +- 0.4ºC, free Hb of 15.2 +- 3.0 mg/dL, aqnd K+ of 5.0 +- 0,5 mEq/L. Normal Saline at 70ºC resulted in a temperature of 29.4+- 0.7ºC, without any increase in free Hb and K+. However, Normal Saline at 95ºC induced hemolysis with an increase in free Hb to 2142.2 +- 242.1 mg/dL (p<0,05) and in K+ to 6.6 +- 2.3 mEq/L. Therefore, NS at 70ºC did not cause hemolysis. This technique is simple, fast, inexpensive, and it can be used in catastrophes