A treatment routinely given to heart attack victims since the 1920s has been shown to do more harm than good to the patient, researchers reported.
In the first controlled human study to show adverse effects of sodium bicarbonate - commonly known as baking soda - scientists found that "probably in most cases it has made things worse.""People who survived cardiac arrest probably did so despite the bicarbonate," the University of California, San Francisco, researchers write in the July issue of the American Journal of Medicine.
Heart attacks - the leading killer of Americans - caused 524,100 deaths in 1986 and are expected to strike 1.5 million Americans this year, according to the American Heart Association.
Sodium bicarbonate has been routinely administered to almost all cardiac arrest patients for more than 70 years, noted Dr. Allen Arieff, UCSF professor of medicine and chief of geriatrics research at the Veterans Administration Medical Center.
"Although its merit never was proved, bicarbonate injected by vein has been used over the years to combat lactic acidosis, a condition in which lactic acid accumulates in the blood and poisons the body by upsetting its delicate acid base balance," he said.
Normally, the liver breaks down lactic acid - a natural product of metabolism, Arieff said. During a heart attack or cardiac arrest, however, the liver receives too little blood and slows down, causing the blood acid level to go up.