Heating Up the Blood

Of the 2,000,000 or more Americans who get transfusions every year, too many die on the operating table, and some as the result of a medical mistake. Surgeons and anesthesiologists, who are cautious about matching blood groups, have been ignoring the fundamental fact that circulating blood is warm; they have been pouring refrigerated blood into their patients' veins.

A single pint or two of blood that has been kept chilled to 40DEG F. to keep its red cells from deteriorating might do no harm. And it is usually out of the icebox long enough to warm up a little before surgery. The body can handle the difference in temperature when the volume of the transfusion is not too large. But if a surgery patient needs several pints, the shock of the frigid flood fresh from the blood bank may kill him.

The heart is the first organ that the cold blood reaches after it is dripped in through an arm vein, and the heart is sensitive to cold. Excess chilling can easily cause it to stop or go into useless twitching (fibrillation) from which the patient may never recover.

Guarding against such an accident is easy. In the Annals of Surgery, Dr. C. Paul Boyan of Manhattan's Memorial Sloan-Kettering Cancer Center describes a plastic coil immersed in a bath of water kept at blood heat. The blood, passing through the coil on its way from the transfusion bottle to the patient's arm, reaches his heart at just the right temperature. Heart stoppage used to occur in about 50% of patients who got six pints or more of chilled blood; it occurs in only 7% now that they get coil-warmed blood.

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