Immersion warming of blood before transfusion

We compared a simple method of warming stored blood by immersion of blood bags in warm water, to the standard method using portex blood warming infusion coils, which are not freely available in Sri Lanka. The mean temperature of blood after warming by immersion of blood bags was 29.5 degrees C and by infusion coil 30.2 degrees C. The values were within the confidence limits of each other. Ten units of blood in each group were compared with regard to changes in free haemoglobin (Hb), packed cell volume (PCV), and hydrogen ion concentration, and no statistically significant difference was observed. We recommend immersion warming as a safe and effective alternative to warming by infusion coil.