[The effect of rewarming of stored blood on plasma value and erythrocytes].

30 units of stored blood of different age were rewarmed from 4 degrees C to 32 degrees C by microwave blood-warmer Infusotherm 407. The resulting damage to blood components and change of function of erythrocytes were compared with those caused by storage of CPD-blood. Dependent on the age of stored blood we found considerable increases in the plasma-levels of potassium, lactate, and free haemoglobin. Compared with cold CPD-blood rewarming of stored blood produced a 7% increase in lactate and a 8% increase in free haemoglobin. There were no changes in platelet and erythrocyte counts, haematocrit, plasma-levels of haemoglobin, electrolytes, cholesterol, blood viscosity, osmotic resistance, and oxygen-binding capacity. As damage of stored blood produced by warming is minimal compared with that produced by storage, the Infusotherm 407 is considered to be a clinically useful blood-warmer.