Canadian Medical Association Journal 1996; 154: 391-397
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Introduction
This is the first article in a two-part series dealing with changes in transfusion medicine and physicians' use of blood and blood products.
When Margaret Shenfeld had her first spinal operation in 1984, she received five units of donor blood. It was the year before the Canadian Red Cross Society began screening donations for HIV, and the timing would not be lost on the Toronto dentist. For years she wondered if she could have been one of the more than 1100 Canadians infected with HIV through the use of tainted blood and blood products. "I was very fortunate," she says. "I got away with it that time, and I didn't want to take a chance again."
In 1992, Shenfeld faced another back operation. This time, a little wiser and much more wary, she took matters in hand and asked to bank some of her own blood for surgery. Banner headlines about HIV and other blood-borne viruses made her nervous, and she had watched her daughter nearly die from a transfusion reaction. The Toronto Hospital, however, didn't have an autologous program, so her physician, at Shenfeld's request, referred her to the local Red Cross.
Today, she tells a different story. In preparation for her third spinal operation, on Oct. 26, 1995, the neurosurgeon told her to give three units through the Toronto Hospital's 8-month-old autologous program. "I didn't have to ask this time," she says. "He said he wanted me to donate my blood, and the hospital would call and arrange for it."
It's a sign of the times. Thanks in large measure to patient demand and the Krever inquiry into the safety of Canada's blood supply, more hospitals are adding autologous programs to their list of services. It's only one part of a larger trend to reduce reliance on donor blood. Surgeons, anesthetists and other doctors have kicked some of their old transfusion habits in favour of nonblood treatment techniques. In some quarters, this has translated into remarkable gains. The Toronto Hospital, Canada's biggest blood user, cut its red cell consumption by 43% between 1989 and 1994.
Although many doctors believe a disproportionate amount of energy and money is being spent on the blood system, others say it's about time. "It's an area that has received too little funding and attention in the past," says Dr. Gershon Growe, medical director of transfusion services at the Vancouver Hospital and Health Sciences Centre. "We should get our house in order since we have the opportunity to do it."
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What's the risk?
Although the blood supply is considered safer than ever, there's good reason to eliminate unnecessary transfusions. In his interim report, Justice Horace Krever wrote that "more than 25 infectious agents have been known to be transmitted through the use of blood and blood products. Other known and emerging infectious agents can, potentially, be transmitted by blood and blood products."
Foremost is the risk posed by HIV (1 in 50 000-400 000 units of blood), hepatitis C (1 in 5000-10 000) and hepatitis B (1 in 300 000). Bacterial contamination, transfusion reactions and immunosuppression are also cause for concern. "The risks are small," says Toronto anesthetist Lesley Sinclair, "[but] the risks are never small if you're one of the minute statistics."
Nor are most of the risks new. "We've always known transfusion has carried a risk," says Dr. Gwendoline Spurll. "That hasn't changed."
Spurll, the head of transfusion services at Montreal's Royal Victoria Hospital, recalls that during her training in Winnipeg in the late 1970s, all hemophiliacs contracted hepatitis. Around that time, she splashed herself in the face with a pooled plasma product. "It was very scary," she says.
"What's changed transfusion practice is AIDS," Spurll continues. "Even though AIDS is a very rare complication of blood transfusion, it carries such a stigma that it has scared everybody in the field. . . . Hepatitis C is still the major risk, but what everybody is afraid of is AIDS."
Some doctors may not consider the long-term effects of hepatitis C -- cirrhosis or liver failure in about 25% of cases, according to the Krever inquiry -- but at least more doctors now think twice about ordering transfusions. Dr. David Kinloch, chair of the board of the Canadian Blood Agency (CBA), says Red Cross donations provide a glimpse into national trends. Between 1990-91 and 1994-95, he says, donations fell by more than 15%. A few areas have suffered serious blood shortages, but "the reduction in donations has been matched by the reduction in demand."
Over more or less the same period, despite growing caseloads among heavy blood users such as oncology and trauma departments, teaching hospitals like Montreal's Royal Victoria, Toronto's Sunnybrook Health Science Centre and the Vancouver Hospital and Health Sciences Centre have recorded respective 10%, 15% and 20% decreases in red cell transfusions. Moreover, fewer patients are being "incidentally transfused," says the Vancouver Hospital's Gershon Growe. "The number of patients being transfused has dropped by 25%, and that's with an increase in acute care at this hospital."
"Probably the most illuminating thing about how practice has changed is the proportion of people who get transfused," says Dr. David Anderson, Growe's counterpart at the Victoria General Hospital (VG) in Halifax. "In the mid-1980s, virtually 100% of [cardiovascular surgery] patients would get a blood transfusion. In 1994, that decreased to 29%.
"In the early to mid-1980s, doctors were just hanging blood when a person came into the OR without waiting to see what would happen. . . . A lot of the grey-zone practices . . . that existed years ago just don't happen now."
Anderson has recently completed a study of transfusion practices at the VG. Findings revealed a 50% decrease in red cell transfusions between 1986 and 1994 and a similar decline in plasma transfusions. "When you factor in situations like oncology where, if anything, transfusion requirements are going to increase over time, the figures are even more impressive," he says.
As late as 1992, however, Dr. William Ghali and others at Queen's University were finding "significant unnecessary blood use" among surgeons and internists at a medium-sized teaching hospital in Kingston, Ont. (see Ghali WA, Palepu A, Paterson WG: Evaluation of red blood cell transfusion practices with the use of preset criteria. CMAJ 1994; 150: 1449-1454).
Even today, says Dr. Robin Hutchinson, the attitude among doctors "still varies." Hutchinson, past chair of the CBA board and medical coordinator at Nanaimo Regional Hospital on Vancouver Island, is an internist who trained at McGill University in the 1960s. He was taught that blood was a "dangerous drug" to be administered "sparingly and carefully."
He says red cell transfusions are down about 30% overall in BC, but he's "still quite surprised and somewhat perturbed by the cavalier attitude of some doctors toward giving a couple of units of blood for somebody who is a little wobbly or looks a little pale. It's even been thrown at me that this is a matter of utilization management, that if you fire in a couple of units of blood, you can get patients back in their homes quicker."
One hopes that's more the exception than the rule. Nevertheless, as VG anesthetist Dr. Allan McIntyre suggests, the medical profession is "in a transition phase. There's a lot more discussion on giving blood than there used to be. Then again, if you sit a lot of us down, to get hard numbers and hard methods of how doctors decrease their blood utilization, you'd probably get some interesting answers."
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Reducing blood use
Like Margaret Shenfeld, Sunnybrook anesthetist Lesley Sinclair had a blood transfusion before the era of HIV screening. "When I went for my first AIDS test," Sinclair recalls, "I thought, `God, maybe I was one of the people who got AIDS from blood.' Fortunately it was fine, but I always think about that. I wouldn't want somebody to give me blood unless I absolutely needed it, and that's sort of the philosophy I use."
It's an approach that's been gaining ground since the late 1980s, when a National Institutes of Health consensus conference concluded that perioperative transfusion decisions should depend on the patient's condition, not on optimal hemoglobin levels. In 1992, the American College of Physicians seconded that finding in clinical guidelines published in the Annals of Internal Medicine (1992; 116: 403-406).
"Every patient is supposed to be reviewed individually, and that's been a big change over the past few years," says Gershon Growe. "Anesthetists and surgeons liked to have patients with a hemoglobin [level] over 100 [g/L] or they wouldn't take them for anesthetic, but that's not the case any more. . . . We often see patients postoperatively with hemoglobin [levels] between 80 and 100 who are not being transfused because they are quite stable."
In some hospitals, such as the VG, average hemoglobin thresholds appear to be even lower. Experts agree that surgery accounts for more than half of the blood used in hospitals. Growe, for one, hasn't "met one group that doesn't want to cut down on its blood utilization." Although he has noticed "a decrease across the board in almost all surgery," he and other doctors generally say that of the traditionally steady users, orthopedic and cardiovascular specialties have made the most headway.
"We talk about it more in cardiovascular because we have the potential for using so much blood and also the potential for saving so much," says Al McIntyre. "Even in these patients, who most people would look at and say, `My God, you can't let this patient get anemic,' we've found that, yes, we can -- within reason."
Efforts aren't confined only to adult populations. At the British Columbia Children's Hospital, Dr. Jacques LeBlanc, head of cardiac sciences, says the proportion of open-heart operations done without donor blood or blood products rose from 20% in 1993 to 35% in 1994, thanks to modifications in equipment.
He hopes the number will reach 50% within a year, and plans to introduce a protocol for the use of erythropoietin. "We're following the pressures of the population and we're following the technology," LeBlanc says, noting that about between 5% and 7% of parents insist on no blood for their children. "But there's a limit. I cannot go down to zero."
Some of the techniques doctors employ widely to avoid blood transfusions originated in Canada more than two decades ago. When Dr. Raymond Heimbecker became chief of cardiovascular surgery at University Hospital in London, Ont., in the early 1970s, he "was told right from day one" that the area's limited blood supply couldn't support another cardiac-surgery program.
By making alterations to the heart-lung machine, Heimbecker and his colleagues pioneered an intraoperative recycling system that suctioned blood shed during surgery, circulated it through a filter, then reinfused it intravenously. They also routinely primed the heart-lung machine with a saline solution, not blood, to achieve some hemodilution.
Heimbecker says they found that patients' own blood was "vastly superior" to banked blood in clotting ability, platelet levels, and oxygen-carrying capacity. Contrary to some evidence of the day, they also showed that "the blood left behind in the heart-lung machine should not be poured down the sink but should be returned to the patient."
Between 1974 and 1986, when he retired, Heimbecker and his colleagues performed hundreds of elective and emergency cardiovascular operations using those and other methods. The majority of patients, two-thirds of whom were Jehovah's Witnesses, didn't receive any donor blood or blood products. "As I look back on it now," he muses, "I wonder how many patients avoided HIV because of these techniques that at that time didn't seem of earth-shaking importance."
It's a good question, but Heimbecker says physicians elsewhere showed only "moderate" interest in those techniques. "Most people back then thought it was expensive and time consuming, and the blood banks were full," says Dr. John Sullivan, head of cardiovascular surgery at the VG.
Sullivan changed his mind when a group of patients at the VG, including Moncton surgeon Orville Messenger (see Robb N: A surgeon with AIDS made the most of borrowed time. CMAJ 1996; 154: 223-225 [abstract / résumé]), contracted HIV. "That was a wake-up call for most of us," Sullivan recalls.
"[HIV] has changed surgical practice," he says. "Formerly, surgeons would be ready to close a wound that was somewhat wet with the thought process: `Well, so what if we have to give a couple of transfusions afterwards?' Surgeons are much more diligent about hemostasis now. . . . Everyone uses the cautery."
Careful attention to blood loss and recycling isn't the only development over the past decade. Sullivan and others say that, among other innovations, drugs that inhibit bleeding and cell-saving devices that wash blood and concentrate red cells have also helped reduce consumption. So, too, has the use of crystalloid or colloid solutions to prime cardiac equipment and a synthetic volume expander called pentastarch. (A few observers told CMAJ that some physicians still reach too quickly for albumin or plasma in these and other situations.)
On Sullivan's desk is a pie chart showing that during the first 6 months of 1995, about 22% of cardiovascular surgery patients at the VG received blood. He says patients who get blood tend to be elderly, small and anemic, or emergency patients. It also depends on whether the person has been taking acetylsalicylic acid or is having a "redo" operation, says Dr. Ernest Michel.
Michel, an anesthetist at the Toronto General Division of the Toronto Hospital and chair of the hospital's transfusion committee, says the General's liver transplant program is the "major user of blood now -- it's not cardiac any more."
He estimates that in his own practice, 30% to 40% of which involves cardiac care, he orders blood transfusions for fewer than 10% of patients. "It's rare, it's uncommon," he says. "When I make the decision that it's time now to give a patient blood, I have the nurse bring it into the room, and before I commit myself . . . I ask myself again: `Is this really indicated?' I'm happy to say I can't remember sending a unit back to the fridge."
Blood transfusion "is a big issue now," he continues. "We look on it as a major event in the course of a procedure." Indeed, the Toronto Hospital's head of cardiovascular surgery, Dr. Tirone David, who Michel calls a "champion of dry surgical fields," recently told CBC's The Health Show that only about 15% of patients get blood.
But those gains don't come cheaply. "The problem we have now is we are all thinking about cost," says Michel, stressing that "resources" would never be withheld from patients. "We're trying to identify patients who are going to need [such drugs] and those who aren't." Cell saving, particularly useful in abdominal aortic aneurysm surgery, costs about "1000 bucks a pop," he adds.
One cost-effective method that doesn't appear to be widely used is perioperative hemodilution. After administering anesthesia, the anesthetist collects up to four units of a patient's blood, replaces it with a crystalloid or colloid solution, then reinfuses it during or after surgery. "We don't do a lot of that at the moment," says Michel. "I expect we're going to in the future because there is some work in the literature that suggests there are savings to be made."
Meanwhile, such techniques have brought "a whole different spectrum" to anesthesia practice that is "certainly not harmful to the patient as long as you are monitoring the situation closely," says Lesley Sinclair, who noted that anesthetists make most transfusion decisions in the OR. "Most of us try and implement all the things we know we can do. Blood is an expensive resource, too, never mind the potential risks."
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Self-donations
Autologous donation programs sprouting in hospitals across the country are another measure of the medical community's and public's desire to reduce reliance on donor blood. Of the six teaching hospitals canvassed by CMAJ, four had introduced programs in the past 5 years and one hopes to do so.
Canadian Red Cross Society blood banks have been offering a service since 1988, "but it excludes anybody who has coronary artery disease, who is over a certain age -- just about anybody we would be operating on," says Dr. Paul Walker, surgeon-in-chief and vice-president of the surgical directorate at the Toronto Hospital. "So we have funded our own program to meet that need because we feel so strongly that is the way to go and the way patients want to go."
The Toronto Hospital introduced its program in early 1995, but initiatives aren't confined to tertiary care centres. In BC, for example, at least 10 hospitals now offer autologous donation to some degree, says Gershon Growe. Even the Lethbridge Regional Hospital in Alberta, which discontinued its program in 1993 due to lack of funding, has decided to resume it, says hospital blood bank director Dr. Barbara Happel.
Demand for autologous donation has been growing. According to the CBA's David Kinloch, Red Cross autologous collections increased from 5000 in 1990-91 to 18 000 in 1994-95. They are expected to reach 26 000 this fiscal year.
At the Toronto Hospital, transfusion services director Dr. William Francombe says the autologous program has expanded from 1 day a week to 5, with about 150 patients participating during the first 8 months of 1995. Growe says that in 1995 demand has nearly doubled at the Vancouver Hospital and Health Sciences Centre, which set up a "high-risk" program 3 years ago.
Growe attributes the slow start to lack of public awareness about the risks of blood transfusion. Others, however, suggest doctors should shoulder some of the responsibility. "It's still in the realm of the surgeon to initiate autologous blood donation," says Vancouver Hospital anesthetist Terry Waters. "And the problem with that is it's difficult to educate the surgeons. Some are online and onside, but some aren't. We see lots of patients who would have been very good candidates for autologous donation. It'll come, it has to for a variety of reasons."
Maybe so, but autologous donation has limitations. It can be used only in elective surgery, and patients can bank no more than four units of blood. It's also not an option for Jehovah's Witnesses. "The Mayo Clinic looked at its . . . local community," says Dr. Peter Pinkerton, director of clinical pathology at Sunnybrook Health Science Centre, "and they figured that no matter what they did, they couldn't recruit more than 10% of their transfusion needs through autologous blood."
Pinkerton says that at Sunnybrook, which has large cancer treatment and trauma care programs, "3% to 5% of our transfusion needs are being met by autologous blood." By the end of 1994, Sunnybrook's program, introduced in 1991, had collected more than 2000 units from more than 900 patients.
Indeed, the Krever inquiry has drawn criticism for not examining the cost benefits of hospital-based autologous programs. The Royal Victoria Hospital's Gwendoline Spurll believes eligible patients should be referred for autologous donation. But, she says, "it's extremely expensive per life saved."
Spurll developed a protocol for autologous donation in the late 1980s, but when the Red Cross announced it intended to offer the service, she didn't pursue it. Since then, she says, demand hasn't increased enough to justify an in-house program.
"Taking blood sounds very simple," says Spurll, "but in fact the protocol for taking blood that is going to be stored for up to 35 days is quite complicated. . . . If you start setting up autologous programs in each hospital, there is going to be a learning curve, and you may never get past the learning curve because the volume is so low.
"Several years ago, the rate of [bacterial contamination] was in the range of 1%," she says. "That's a significant risk, it's a major life-threatening risk. And as soon as you have centres with smaller volume, the risk goes up."
Other transfusion service directors acknowledge such risks, but they report only cases of dizziness. "We have found we can take blood safely from almost anyone," says Growe.
Pinkerton agrees: "The quality of what we're producing, as far as I can tell, is at least as good as the Red Cross."
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What does the future hold?
Experts predict that by the turn of the century, homologous blood could be largely replaced by artificial substitutes and other alternatives. "For the time being," says the VG's John Sullivan, "blood transfusions are life saving for a small percentage of patients, and they should continue to be so."
Few would disagree. But doctors such as Gwendoline Spurll say more effort is required, especially in continuing medical education and the development of new, safer products. "We still need to work on ways of helping people other than by transfusing them," she says.
Interest in blood management continues. According to David Kinloch, the CBA has been asked to coordinate the development of national clinical guidelines. It has also been guiding the creation of a national database to monitor blood usage and "permit comparisons between jurisdictions and over time."
The database is being assembled by the Canadian Institute for Health Information. By tapping automated hospital records, it will track the number of patients being transfused, the type of blood component or product used, and the clinical indication. It will also enable hospitals to conduct more frequent audits of blood usage.
Meanwhile, research continues. Paul Walker, also president of the Canadian Society for Clinical Investigation, says the Toronto Hospital is taking part in three clinical trials. A study on pentastarch has recently been completed, and multicentre trials on a "hemoglobin-like substance" and on hemoglobin levels and transfusion are getting under way.
"The actual use of blood has gone down dramatically over the course of the last 5 years," Walker says. "[But] nothing happens overnight. These are slow steady steps [in one] direction."
He pauses for a moment. "There's been a fair amount of work done by the Rand Corporation and others on the changing of practices," he says. "They have not been terribly optimistic that doctors are capable of changing except through financial incentives.
"Finances are shaping how we practise in many ways. On the other hand, if you take [blood usage] as an example, people are shifting because it's the right thing to do and [you can't] ignore patient requests [any more]."
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Informed consent and blood tranfusions
Publicity surrounding the Krever inquiry has boosted patient awareness of the potential complications of blood transfusions. "Even if they don't verbalize it, we know patients would rather not get blood," says Halifax anesthetist Al McIntyre. "And if they have received a unit of blood . . . they go home with a little question mark in their mind: `My God, is something going to turn up in the next few years that I may have contracted from blood?' "
These days, McIntyre doesn't wait for patients to ask. "If it's an operation where there's a chance the patient will get blood, I will bring it up," he says. "I try to put it in perspective. I tell them that the possibility of a problem arising from a blood transfusion is less than having a major problem with surviving [the] operation."
He's not alone. More doctors are taking the initiative and discussing transfusions with patients. "Before we never mentioned it," says Toronto anesthetist Lesley Sinclair. "The patient usually brought up the subject. Now we do."
As hospitals heed Justice Horace Krever's recommendations on informed consent (see Capen C: Informed consent and blood transfusions: What does Krever's interim report mean to doctors?. CMAJ 1995; 152: 1663-1665 [abstract / résumé]), physicians may not have much choice. "Unfortunately, there isn't any sort of guideline or homogeneity as to how we're supposed to do this, either on the consent-form side or the acknowledgment-of-transfusion side," says Dr. Robin Hutchinson of BC's Nanaimo Regional Hospital. "Everybody is having to reinvent the wheel or go their own way."
Hutchinson says a recent meeting of hospital medical directors in BC illustrates the range in approaches. "There was a wide scatter all the way from quite formal consent forms that were lengthy and detailed, to the general consent to treatment, to nothing," he recalls.
Nanaimo Regional Hospital has opted to draft a separate consent form, as well as a form for patients to sign acknowledging that they have received blood. In Toronto, Sunnybrook Health Science Centre has also developed a "consent for blood or component transfusion," although it has chosen to notify blood recipients and their family physicians through monthly mailings.
"The informed-consent form is at the printers, along with a patient-information brochure to go with it," Sunnybrook's Dr. Peter Pinkerton told CMAJ in October. "I expect us to have implemented this before the end of the year."
Pinkerton says the brochure, which describes the three principal blood components and more, is meant to expedite the consent process. "There are all sorts of other things physicians have to explain, like the potential complications of the surgery, the risks of anesthesia and so on," he says. "Anything you can do to streamline the process without compromising the patient's right to information is worth while."
Others would probably agree, but except for Dr. Jacques LeBlanc of British Columbia Children's Hospital, which has a brochure but no form, few mentioned patient brochures, let alone separate consent forms. Dr. David Anderson says the Victoria General Hospital (VG) in Halifax decided instead to incorporate blood transfusion into its general consent to treatment, though even that didn't occur without debate.
"Some people felt very strongly that we were singling out one of the safer treatment modalities and wanted to know why we weren't picking on general anesthetics or other drugs that have far more side effects," Anderson recalls. "But it was the majority opinion that blood transfusion did deserve that mention. . . . With most drugs, the side effects are up front. Patients aren't going to go home and learn in a year or two that they've developed hepatitis or some other complication."
Dr. Gwendoline Spurll predicts the Royal Victoria Hospital in Montreal may go the same route. Meanwhile, Dr. Gershon Growe says Vancouver Hospital and Health Sciences Centre's Medical Advisory Committee has agreed to instruct physicians to note in charts that they have discussed blood transfusions with patients.
"A lot of the surgeons did not want to have another form around," Growe explains. "We also wanted to make sure that the discussion was done by a physician and not simply indicated on the chart by somebody coincidental to the matter, who got the patient to sign a consent form."
Besides, he stresses, "it's the principle of discussing that's more important than the signed form. I've seen signed forms that aren't really informed consent. They're consent, but they're not informed."
Dr. Paul Walker of the Toronto Hospital agrees. "You're seeing a number of different approaches," he says. "Those are approaches that may become necessary. On the other hand, I don't think that addresses the problem."
What does, he says, is discussing transfusion with patients, "being very clear what their wishes are," and exploring options such as autologous donation.
But not everyone is convinced that informing patients is beneficial. "I've always maintained that if I really wanted to give my patients informed consent, very few of them would consent to the operation," says VG surgeon John Sullivan, who doesn't discuss blood transfusions with patients unless they raise the issue. "You can talk about informed consent till the cows come home, but it's a no-win situation."
Adds Vancouver anesthetist Terry Waters: "I don't like to see us going closer and closer to the American way, with patients being very litigation conscious and having to inform them of every potential risk that could ever happen to them. That can produce anxiety, particularly if it's done improperly."
But he seems resigned. "It's inevitable," he says. "I suppose if we don't do it, a problem is going to arise."