June 25, 2024
This article originally appeared in AABB News, a benefit of AABB membership. Join AABB today to read the rest of this month’s issue.
Originally developed to protect the blood supply from transfusion-transmitted infectious disease, hemovigilance systems have since evolved to address the overall safety and efficacy of blood transfusion and the blood donation process. Although early hemovigilance efforts arose out of concerns over transfusion-transmitted infections, such as HIV and hepatitis, and their sequelae for blood recipients, the field of hemovigilance today encompasses all aspects of the entire transfusion chain—from donor collection through recipient follow-up—for any potential adverse events that may occur.
“Emerging pathogens pose a continued threat to transfusion safety, and a deeper understanding and recognition of noninfectious complications of transfusion continues to develop. Meanwhile, blood establishments maintain a commitment to minimizing risks associated with blood collection from our altruistic donors,” said Opal Reddy, MD, CABP, medical director of transfusion medicine at Keck Medicine of USC and chair of the AABB Hemovigilance Committee. “These concerns and objectives underscore the critical role of hemovigilance systems in monitoring, improving and promoting donor and patient safety.”
Blood transfusions are common medical procedures that can save lives. Approximately 15 million units of red blood cells (RBCs) are transfused annually in the United States, and an estimated 85 million units are transfused annually worldwide.1 Hemovigilance helps to detect, prevent and reduce the occurrence and recurrence of transfusion-related adverse reactions.
“Since blood transfusions are frequently performed throughout the world, it is essential that we have a robust system for monitoring safety,” stated Claudia Cohn, MD, PhD. “The goal of hemovigilance—a vein-to-vein surveillance system—is to improve transfusion safety and learn from adverse events.”
A Look at SHOT
According to the World Health Organization (WHO), 49% of reporting countries have a hemovigilance system; the implementation levels of hemovigilance systems vary among countries.2
The United Kingdom’s Serious Hazards of Transfusion (SHOT) program is internationally recognized as the world’s strongest system for hemovigilance because of its robust data and high-quality reporting.
Since 1996, the U.K’s independent, professionally led hemovigilance scheme has collected and analyzed information on adverse events and reactions in blood transfusion from all health care organizations involved in the transfusion of blood and blood components throughout the country. Data submitted by hospitals across the U.K. and from the four U.K. Blood Services is collated and analyzed by the unit to produce surveillance reports and inform or evaluate policy changes relating to infection risk.3
Once voluntary, SHOT is now professionally mandated with a high participation and engagement rate throughout the country. Each year, SHOT releases a report and summary providing an analysis of transfusion-related errors from the previous year and publishes recommendations to improve patient safety.
The total number of reports analyzed and included in the 2022 Annual SHOT Report is 3,499—a 10.7% increase from 2021.4 For the first time in 2021, all U.K. National Health Service (NHS) Trusts/Health Boards involved in transfusions submitted reports.
“Although our passive reporting system is dependent on reporters entering a report to inform us of their experiences, we still have a very good reporting culture, and we expect that to continue. However, we are aware that there are areas of under-reporting, such as cell salvage related events, hyperhaemolysis, etc., which we are hoping to address,” explained Shruthi Narayan, medical director of SHOT. “The confidential nature of the reporting system and the fact that improving safety is the main guiding principle for hemovigilance activities helps facilitate the good reporting culture.”
Su Brailsford, PhD, consultant in Epidemiology and Health Protection, NHS Blood and Transplant (NHSBT), discussed the role of lookback investigations, which are initiated when the U.K. Blood Services newly identify markers of infection in a donation from a repeat donor. This may arise due to the introduction of a new screening test, such as the hepatitis B antibody testing implemented in 2022, Brailsford pointed out.
“All U.K. blood services keep archive samples of previous donations for at least three years, so sometimes we’ll go back and retest those samples,” she stated, noting a full clinical lookback will be instigated if the sample is identified as positive. Although, in some cases, lookback will be extended even if the archive sample is negative.
NHSBT identified eight positive repeat donors who required lookback investigations in 2022; 19 of the components investigated were transfused.5
“The investigation sits firmly within the individual blood services, and we generally will complete it in a timely manner,” Brailsford noted. “Sometimes, we’ll go back to donors and ask for additional samples, and usually they’re quite happy to do that.”
Improving Patient Outcomes
Released every summer, the globally recognized and highly anticipated SHOT report provides an effective benchmarking tool that includes chapters on laboratory and clinical errors, near miss reporting, donor hemovigilance and reactions in patients.
“SHOT data provide guidance if we suddenly start seeing transmissions of infections that we haven’t seen previously, which is what happened with transmissions of hepatitis B from donors with occult hepatitis B infections,” Brailsford noted. “We have good evidence that the SHOT data being used in policy decisions can improve patient outcomes. The data reveal the infections we have managed to get a good hold on and ones that need constant monitoring.”
According to the 2022 SHOT Annual Report, trans- fusion delays and transfusion-associated circulatory overload (TACO) continue to be the most common causes of transfusion-related mortality in the U.K., accounting for 21 of 35 deaths reported to SHOT in 2022. Errors (including near misses) continue to account for the majority of the reports—transfused laboratory errors increased by 10.8%, totaling 431, and reports where the error occurred in the ED have nearly doubled since 2020. In addition, there were two patient deaths resulting from six ABO-incompatible transfusions. 4
Narayan noted that 83% of reported events that caused patient harm were avoidable errors often attributed to staffing, communication and/or system issues. This figure includes errors with no harm to patients but had the potential to do so, such as near misses and right blood, right patient errors. The continuing trend of a high percentage of errors may reflect that systemic factors are not properly identified or rectified, leading to short-term results rather than sustained improvement.
Errors related to IT systems and related equipment—where IT systems have been used incorrectly or not implemented properly—also posed a significant challenge.
“We have been looking at the human factors and ergonomics (HFE) perspective quite a lot, and we see encouraging signs that more people are adopting the HFE approach for incident investigations,” said Narayan. “However, there are numerous systemic issues still at play, such as the allocation of appropriate resources, both human and IT, which is primarily contributing to what we see.”
Quality Improvement
SHOT is often lauded for its commitment to openness, accessibility and transparency, and its proactive measures to improve outcomes. Key messages and recommendations in SHOT’s 2022 Annual Report emphasize safe staffing, well-resourced systems, patient safety culture, learning from near misses and shared care and addressing knowledge gaps, transfusion delays and transfusion errors.
“We do realize where there are avoidable transfusions happening or errors in the transfusion decisions,” Narayan said. “Hemovigilance reporting gives us a finger on the pulse. It can shine a light on poor practices and help us improve transfusion decision making, which can improve outcomes.”
The evidence gathered has guided the development of new patient information resources to improve the informed consent process and shared decision-making process. In addition, SHOT has collaborated and continues to work collaboratively with Medicines and Healthcare products Regulatory Agency (MHRA) as the regulator and other key stakeholders in the U.K. to develop educational resources in various formats, including short, animated videos on monitoring the safety of blood supply, infographics and key safety messages to educate staff and optimize learning from hemovigilance. All these resources are freely available from the SHOT website and the SHOT App.
“Improving transfusion safety is at the heart of everything we do and underpins all hemovigilance activities,” Narayan stated. “Hemovigilance plays a fundamental role in enhancing transfusion safety by learning from experiences and then putting in place system changes to improve safety. It’s not data collection for collection’s sake; the intelligence distilled from the submitted reports should inform improvement actions and enhance transfusion safety.”
Reducing Risk
Since 1996, the risk of transfusion-transmitted infections in the U.K. remains low, with only 43 con- firmed cases, involving 35 donors. Among these, HBV and HEV were the most reported proven viral transfusion-transmitted infections.4 The joint NHSBT/UK Health Security Agency (UKHSA) Epidemiology Unit identified the first confirmed transmission of hepatitis B from a donor with occult hepatitis B infection (OBI) to two recipients in 2022.5
“As an epidemiology unit, we keep a close eye on what’s happening in the general population. For 28 years, we’ve made a point to look backward and forward to identify where various mitigation techniques were put in place,” Brailsford said. She credited donor selection criteria and the introduction of bacterial screening for successfully reducing the risk of bacterial transfusion-transmitted infections.
“Similar to North America, we’ve moved to a more individualized approach to donor selection (FAIR), so we’ve significantly increased our monitoring to ensure there’s no adverse impact,” Brailsford told AABB News. “Over time, the epidemiology of major infections like HIV and Hepatitis C decreased significantly in the general population. But then we’ve seen new things being identified like occult hepatitis B.”
Speaking the Same Language
AABB has a long history of collaborating with government agencies, international organizations and experts in the field to establish and implement systems and processes for identifying and tracking adverse reactions and incidents associated with blood collection and transfusion.
“AABB continues to support the advancement of hemovigilance through its Hemovigilance Committee and Donor Hemovigilance Working Group in collaboration with national and international hemovigilance agencies and organizations,” Reddy told AABB News.
In the 2022 Annual Report, SHOT recommended that all U.K. Blood Services implement the AABB ‘Severity Grading Tool for Blood Donor Adverse Events,’ developed in 2020 by the AABB Donor Hemovigilance Working Group and endorsed by International Society of Blood Transfusion (ISBT), International Haemovigilance Network (IHN) and European Blood Alliance (EBA).
Mary Townsend, MD, vice president and corporate medical director at Vitalant and chair of the AABB Donor History Task Force (DHTF), said the tool was created to enhance objective assignment of severity. If you track donor adverse events through hemovigilance, everyone must speak the same language, Townsend added.
“One country may consider a reaction mild while another country considers it severe,” Townsend explained. “We set out to determine a strictly objective severity grading tool, and we patterned it after an established clinical severity scale, the Common Terminology Criteria for Adverse Events [CTCAE] v 5.0. Many countries have adopted the severity assignment tool since its development.”
Closing the Gap
Narayan noted that transfusion safety data shows the risk of transfusion-transmitted infections is extremely low in the current times.
“The data tells us the actual gaps in our system are not about making the blood components safer, which will always be a priority. Our findings highlight a need to improve the transfusion decision-making process and address process-based safety,” Narayan said. “We see the impact these issues have on transfusion recipients, especially patients entering shared care service or individuals with sickle cell disease or thalassemia who require frequent transfusions.”
Narayan posed the question: How do we develop a coordinated process with seamless communication among all teams involved in the care of the patient? Appropriate and effective implementation of IT vein to vein with easy access to relevant transfusion records is vital to support safe transfusion decisions. Narayan added, “We will continue to learn and improve. It is encouraging to see many recommendations supporting hemovigilance, patient blood management, transfusion education, laboratory support and digital transformation within transfusion.
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