_This is the second part in a three-part series, “Medicine Without Blood,” about the ways that Jehovah’s Witnesses have changed the way that doctors think about blood transfusion. Read the first and third installments, “How Jehovah’s Witnesses Are Changing Medicine” and “The Ethics of Bloodless Medicine.”

_

The United States’ full embrace of blood transfusion began during the Second World War, when large-scale blood donation and mobilization became part of the war effort. “Your blood, as a gift, is unlike money, unlike time or work,” one radio broadcast, titled “Women at War,” announced. It was a gift “to an American soldier or sailor, who may live to save all that you count precious in the world.” One Marine Corps correspondent described the arrival of blood at a medical station in the Pacific: “the wine-colored bottles were held aloft above the prone bodies [of wounded men] and the stuff was doing its miraculous work.” It was the “most precious cargo on this island of agony.” Japanese troops had nowhere near the same access to blood, which only heightened its symbolic power. The Germans, too, were hampered by a refusal to collect from non-Aryans, a policy that “eventually frustrated even their own physicians,” according to the journalist Douglas Starr, whose book “Blood: An Epic History of Medicine and Commerce” details this history.

After the war, donated blood became an integral part of Western medicine. Advances in care, including open-heart surgery, artificial kidney replacements, and trauma work “consumed huge amounts of blood,” Starr writes. Doctors also transfused patients to top off their hemoglobin levels following procedures like tonsillectomies, appendectomies, and even childbirth. Yet, in the thrall of wartime transfusion, blood had never been treated like an experimental drug and subjected to rigorous, randomized clinical trials assessing risk and benefit. Its power was intuitive. Doctors observed that patients with anemia seemed to feel better following transfusion. “The patients looked rosy and felt full of energy,” one older doctor told me. No one was thinking yet about adverse effects.

This made it difficult for Jehovah’s Witnesses who developed anemia or needed major surgery. The religion’s governing body had decided that passages in the Bible, which instruct adherents not to consume blood, meant that they should avoid transfusion. The mixing of blood seemed to them a form of existential contamination. Yet most Witnesses still wished to receive medical care. And “in some doctors’ minds, there was confusion,” Zenon Bodnaruk, of Hospital Information Services at the Jehovah’s Witnesses’ world headquarters, in Brooklyn, told me. Some doctors believed that the religious objection to blood transfusion was tantamount to a refusal of care. One frequent scenario involved patients with heart disease who needed coronary-artery bypass grafts or cardiac-valve-replacement surgeries, both of which involved substantial blood loss and were nearly always accompanied by transfusion. Jehovah’s Witnesses were repeatedly turned away by cardiac surgeons or “asked to reconsider their religious position on blood,” Bodnaruk said.

Still, a small number of doctors were willing to accommodate requests for bloodless treatment. In the late nineteen-seventies, Watch Tower leaders decided to cultivate relationships with these physicians. In the late eighties, the governing body approved a large-scale effort to help Witnesses find sympathetic care, according to Bodnaruk. In the early nineties, one of the institutions that Witnesses contacted was Englewood Hospital and Medical Center, in New Jersey, which welcomed them. Aryeh Shander, a voluble, grandfatherly man who was then the chief of anesthesiology at Englewood, became an important advocate for their cause. His empathy for religious minorities was strong, he said, because his mother was a Holocaust survivor and had impressed on him the importance of “always looking out for human rights.” At the same time, he had developed an academic interest in blood transfusion, which he believed, based mainly on intuition, was overused in surgery. There wasn’t any real evidence yet to prove him right or wrong.

From the beginning, the bloodless program at Englewood enjoyed anecdotal success. In small observational studies, the witnesses’ surgical outcomes seemed to match those of other patients undergoing the same procedures. By the late nineteen-nineties, Shander and his team were committed to applying the lessons of bloodless medicine to non-Witness patients. Englewood was not alone in this experience. Numerous bloodless-medicine programs had sprung up around the same time in the United States, thanks to the Jehovah’s Witnesses’ advocacy.

Meanwhile, the prevailing attitudes toward blood had grown more fraught, in the U.S. and elsewhere. Since the late nineteen-sixties, when patients with hemophilia began to use clot-promoting proteins that were derived from large pools of donor blood, they had been vulnerable to infection, especially hepatitis. In the early eighties, however, with the emergence of AIDS, risks soared. Before the development of an H.I.V. screening test for donors, in 1985, almost half of all hemophiliacs became infected with the virus.

Lawrence Tim Goodnough, who is now the director of the transfusion service at Stanford Medical Center, was a fellow in hematology oncology just as the H.I.V. epidemic began. His experience with hemophiliacs, in particular, inspired in him a lifelong interest in reducing patients’ exposure to blood. “I was not coming primarily from a Jehovah’s Witness point of view,” he said. But as bloodless-medicine programs developed, in the late nineteen-eighties and nineties, he found that the clinicians running them made natural bedfellows. Their experience was “key to showing how often you can get patients through complex hospitalizations, surgical and medical, without blood transfusions.”

In 1999, the first strong evidence to validate this perspective emerged. In a randomized controlled trial published in the New England Journal of Medicine, Canadian researchers found that more restrictive blood-transfusion practices could often be just as good for patients—or better. Interestingly, the lead researcher, a critical-care specialist named Paul Hébert, had expected to demonstrate just the opposite. He and his colleagues enrolled more than eight hundred critically ill patients in intensive-care units. These patients were not actively losing blood, but they suffered from anemia, a problem in which the blood lacks sufficient hemoglobin and struggles to transport oxygen through the body. Hébert and his team randomly assigned them to receive red-blood-cell transfusions either on a liberal or restrictive basis. After thirty days, the two groups had equivalent mortality. Among patients who were younger than fifty-five or who had less severe conditions, the probability of death was actually lower for those treated under the more restrictive guidelines.

At first, Hébert said he did not believe the results. But over the years, his work has been recognized as “one of the landmark papers in transfusion medicine,” according to Courtney Hopkins, the Chief Medical Officer of the American Red Cross’s eastern division. Numerous other randomized controlled trials have confirmed his core finding, as well. Researchers have compared restrictive and liberal transfusion strategies in critically ill children. They’ve also studied adults with septic shock, gastrointestinal bleeding, and traumatic brain injury, and those undergoing high-risk hip surgery. These papers have either found no difference between the two groups or have found better outcomes in those receiving less blood. (One exception has been patients with acute coronary events, such as heart attacks, for whom the evidence is mixed and may support more liberal transfusion, Hébert said.) Most physicians conducting this research have not worked in programs for Jehovah’s Witnesses. But the Witness community has taken note. So too have leaders of bloodless-medicine programs, many of whom are passionate advocates for reducing transfusion whenever possible. (The Society for the Advancement of Blood Management, the first national organization dedicated to this goal—founded by Shander, Goodnough, and others—has played a key role in disseminating best practices regarding patients’ blood.)