Annual Report 2018–2019

Katy Bennett:  medical services registered nurse

Our organization is completely focused on ensuring quality and minimizing risk.”

Katy Bennett and her colleagues examine adverse events associated with the transfusion of blood and blood components. It’s one more way we’re working every day to maintain a safe, consistent and reliable blood system.

“While some patients do experience adverse reactions to transfusions, those that end up being classified as ‘product-related’ are extremely rare,” says Katy Bennett, a medical services registered nurse with Canadian Blood Services in Ottawa. If a patient has an adverse response, such as a severe allergic reaction, and medical professionals believe it may be related to the transfused blood product, the hospital must alert Canadian Blood Services. That’s where Katy’s team comes in, taking quick action to investigate.

Any reported case results in the immediate quarantine of other related blood products obtained from the same donor and in their assessment for possible retrieval. This could include components in the Canadian Blood Services inventory, at the reporting hospital or at other hospitals across the country. “It means going through clinical histories, figuring out timelines, determining exactly how patients reacted,” Katy explains. “It’s a bit like detective work.”

Built-in vigilance

If an investigation finds a link between the adverse reaction and the administered product, Katy and the rest of the medical services team will take additional steps to mitigate risk and prevent recurrences. The donor may be informed if it affects their eligibility to donate in future. The team will also work with Canadian Blood Services colleagues in quality assurance and regulatory affairs to report the event, where applicable, to Health Canada.

During the past year, we supplied nearly one million units of blood and blood products to hospitals throughout Canada. Red blood cells comprised three-quarters of total shipments (726,548 units); the rest were about evenly split between platelets (115,046 units) and plasma for transfusion (118,231 units).

Across the country, hundreds of thousands of patients annually receive blood or blood products. However, in 2018–2019, we reported only 51 adverse reactions to Health Canada — representing 0.005 per cent of all blood units distributed — many of which turned out to be unrelated to the transfusion process.

Analyzing the nuances

“We start by assessing the information received from the hospital to ensure we have all the details we need,” Katy says. “One challenge is that patients who receive transfusions are often very ill, so it’s not always clear whether their response is actually linked to the blood products. I’ll work with the reporting facility to get more details on the nature of the reaction, how long after the transfusion it occurred — as many nuances as possible. Every story is complex, with a lot of moving parts, so this isn’t always an exact science. But with the combined expertise of our medical teams and their hospital counterparts, we’re able to conduct a thorough assessment and determine the best course of action to ensure the ongoing safety of the blood supply.”

Of the 51 adverse events reported to Health Canada during the past year, just four were flagged as definitely related to transfusion products;  another 10 were judged to be probable, while 15 were deemed possible. The rest were found to be doubtful (8) or indeterminate (2), or were ruled out entirely (12). The most common causes of adverse events during this period were definite or probable/possible allergic and anaphylactic responses. Generally speaking, suspected bacterial infections are more unusual, though they prompt an additional check of the original donation sample or a request to the hospital for additional results of tests performed on patients. Also relatively rare — albeit frequently investigated and ruled out — is transfusion-related acute lung injury (TRALI), a serious complication involving the sudden onset of pulmonary edema.

“We investigated 15 suspected cases of TRALI in the past year,” Katy says, “consulting with our working group of TRALI experts. A dozen cases were ruled out, two were considered possible, and one couldn’t be determined from the evidence.”

Further reducing a remote risk

For any case where there is a potential connection to a transfused product, Katy and her colleagues, as noted above, immediately take action. They identify additional components linked to the donor of the unit associated with the reaction and then manage their retrieval. They may also arrange for further patient or product testing. And they investigate the donor history as well. “We can trace each event back to the specific donor of the product involved,” she explains. “With patients who are treated using more than one product, or who receive pooled platelets — units containing platelets from more than one donor — we may have to investigate several donors. We check whether any donor is flagged in our records as having been associated with a previous adverse reaction. And, of course, if we feel there’s any risk, we’ll recommend that the donor be deferred from future donation.”

In parallel with this focused investigative work, Canadian Blood Services has been collaborating with hospitals and health-care professionals to promote more effective reporting of adverse reactions. “Our organization is completely focused on ensuring quality and minimizing risk,” Katy says. “So, our role in investigating reports of adverse reactions is to determine the cause, manage any risks and prevent recurrences. At the end of day, it’s all about the patients and what’s best for them.”