“real blood has some practical problems. For one thing, it must be kept refrigerated. That makes it difficult to use on battlefields or accident sites, which is a pity because that’s where a lot of bleeding takes place. Twenty thousand people die every year in America from bleeding to death before they can get to a hospital. Globally, the number of bleeding deaths a year has been put as high as 2.5 million. Many of those lives would be saved if people could be transfused promptly and safely—hence the desire for an artificial product. In theory, it ought to be fairly straightforward, particularly because an artificial blood wouldn’t need to do most of the many things real blood does except carry hemoglobin. “In practice, it’s proved to be not so simple,†says Doctor with a fleeting smile. He explains the problem by likening red blood cells to those magnets that you see picking up cars in junkyards. The magnet has to latch on to an oxygen molecule in the lungs and convey it to a destination cell. In order to do that, it has to know where to take the oxygen and when to release it, and above all it mustn’t drop it en route. That has always been the problem with artificial bloods. Even the best-made artificial bloods occasionally drop an oxygen molecule, and in so doing release iron into the bloodstream. Iron is a toxin. Because of the extreme busyness of the circulatory system, even an infinitesimal accident rate will quickly mount up to toxic levels, so the delivery system has to be pretty much perfect. In nature, it is. For more than fifty years, researchers have been trying to make artificial blood but, despite spending millions of dollars, are still not there yet. Indeed, there have been more setbacks than breakthroughs. In the 1990s, some blood products made it into trials, but then it became evident that patients enrolled in the trials were having alarming numbers of heart attacks and strokes. In 2006, the FDA temporarily shut down all trials because the results were so bad. Since then, several pharmaceutical companies have abandoned the quest to make a synthetic blood. For now, the best approach is simply to reduce the volume of transfusions. Bryson, Bill. The Body (p. 136). Knopf Doubleday Publishing Group. Kindle Edition. Bryson, Bill. The Body (p. 136). Knopf Doubleday Publishing Group. Kindle Edition. Bryson, Bill. The Body (p. 136). Knopf Doubleday Publishing Group. Kindle Edition. Bryson, Bill. The Body (p. 136). Knopf Doubleday Publishing Group. Kindle Edition. ”
