Mitigating adverse reactions in youthful donors

In 2004, only 6 states in the United States permitted 16-year-olds to donate blood and 5 of these required parental consent.1 As of July 2008, 29 states, with 4 pending, allowed 16-year-olds to donate including 2 that do not require parental consent; [Correction added after online publication 6-Aug-2008.] at least 6 are considering such permissive legislation (Matt Granato, personal communication). Although expansion of the prospective donor pool to include younger donors is an important step toward enhancing the blood supply, two articles published in the current issue of TRANSFUSION2, 3 and one that appeared recently in JAMA4 remind us that this transition does not come without a cost. Eder and colleagues2 report on donor complication data collected in 2006 as part of the American Red Cross comprehensive hemovigilance program. Data from more than 6 million allogeneic whole blood donations revealed an overall complication rate of 3.48 percent, with presyncopal reactions (e.g., pallor, lightheadedness, dizziness, nausea) accounting for 74 percent of all reactions. Reaction rates varied considerably as a function of age, sex, and first-time donation status, with younger donor age being the strongest independent predictor of complications. Among 16-year-olds the overall complication rate exceeded 10 percent. Similarly, Wiltbank and colleagues3 report on the rate of adverse reactions associated with nearly a half-million allogeneic whole blood donations collected during a 9-month period by United Blood Services. In a sample of donors 17 years of age and older, this study reports an overall reaction rate of 1.43 percent. Mild reactions, defined as “pallor, sweating, anxiety, or symptoms lasting less than 15 minutes,” made up 63 percent of all reported complications. Several correlates of reaction risk were identified (e.g., age, sex, race, blood volume, body mass index, blood pressure, and pulse); however, estimated blood volume, age, and first-time donor status were among the strongest predictors of overall complications. Whereas 17- and 18-year-old donors represented only 9.8 percent of the donor pool, they accounted for 27 percent of all reactions. Although an inverse relationship between donor age and rate of complications has been reported previously,5, 6 in the context of an ongoing debate over the benefit of recruiting 16-year-old donors these recent articles highlight an important question—“Does the benefit of expanding the donor pool to 16-year-olds outweigh the risk if our youngest donors are more likely to experience complications?” The potential costs associated with increased reactions are many, including 1) greater need for staff to attend to reacting donors, 2) higher anxiety among staff collecting blood at high school drives, 3) greater risk of reactions among other donors in the vicinity (particularly in high school settings), 4) discomfort and distress for the individual donor, 5) a decreased likelihood of donor return, and 6) loss of potential future donors as reactors relay their adverse experience to friends and family. Fortunately, there may be a way to gain the benefit of an expanded donor pool without incurring the cost of increased rates of reactions. Specifically, recent research suggests a number of strategies that may help reduce the risk of presyncopal reactions in young donors, including acute water loading,7, 8 applied muscle tension,9-12 and distraction.13 In a randomized controlled trial of predonation hydration, male and female first-time blood donors who consumed 500 mL of water 30 minutes before donating reported significantly fewer presyncopal reactions when compared to donors who did not receive water.7 This finding was later confirmed in a larger study of almost 9000 high school donors,8 also demonstrating that the salutary effects of hydration increased as the interval between water loading and phlebotomy decreased. Applied muscle tensing, which involves repeated, rhythmic contraction of major muscle groups of the arms and legs, has been used for decades to treat fainting reactions in individuals with blood and injury phobia. In the first study to apply this procedure in the context of blood donation, Ditto and colleagues12 used a brief video to teach the muscle tension technique to novice blood donors just before their donation. Compared to a control group that did not watch the video, donors who learned the muscle tensing technique reported fewer vasovagal reactions. This effect was confirmed and extended in a larger study,11 with those who practiced the muscle tensing technique reporting fewer vasovagal reactions and a greater intention of providing a repeat donation. A randomized controlled trial also demonstrated that the beneficial effects of muscle tensing appear to be mediated primarily by lower body tensing and cannot be explained as a simple distraction effect.10 That said, distraction alone may be of benefit to some donors, as it has been demonstrated that blood donors who prefer avoidant coping strategies were less likely to report presyncopal reactions when they watched a 3-D movie while giving blood.13 Finally, it has recently been demonstrated that a brochure providing instruction in these coping techniques can reduce donation anxiety, improve attitudes toward donation, and increase willingness to donate,14 suggesting that education in donor coping strategies can be applied in a manner that is simple and cost-effective. In sum, widespread implementation of predonation education in donor coping strategies may encourage young donors to give blood, reduce their risk of having complications, and enhance the likelihood that they will provide a repeat donation.15, 16 At the same time that we encourage blood collection agencies to adopt coping strategies training as part of the ongoing effort to recruit and retain new donors, it is imperative that we also encourage empirical efforts to monitor their effectiveness in diverse populations. As illustrated by the data presented by Eder and colleagues2 and Wiltbank and colleagues,3 donor reaction rates differ both between blood collection agencies and across collection sites within the same agency. This phenomenon is due to a combination of inconsistent definitions of what constitutes a reaction; different reporting criteria across agencies; and variability in how individual phlebotomists interpret, recognize, and report adverse events. Although uniform definitions and reporting criteria would help to address this problem, it must be acknowledged that some degree of subjectivity is inevitable due to the nature of the reactions. In this regard, it is important to note the AABB's leadership role in establishing a national hemovigilance program in the United States. This system intends to provide a broad-based, uniform reporting structure for adverse events affecting both donors and recipients. Optimally, hemovigilance programs identify causal relationships, but, in fact, they are more likely to highlight topics for further, focused investigation possibly including an assessment of the donor's perception of the event. The coping literature demonstrates that brief screening measures of presyncopal symptoms are easily obtained and can be applied identically across diverse blood collection agencies and settings. Although these ratings are inherently subjective (i.e., donors may vary in the extent to which they are distressed by the experience of symptoms such as faintness, dizziness, or lightheadedness), it is precisely this individual difference in perception that relates to donor satisfaction and willingness to provide a repeat donation.15, 17 In the companion publication by Eder and colleagues,4 serious events occurred in donors weighing more than 130 lbs. This observation implied that raising weight requirements or decreasing collection volumes would have minimal benefit. In contrast, Wiltbank and colleagues3 identified low blood volume, derived from an algorithm using height and weight, as a presyncopal reaction risk factor, particularly in donors less than 24 years old. As such, these studies confirm the usefulness of hemovigilance in identifying opportunities for further investigation. For example, preliminary observations suggest muscle tensing and coping strategies reduce reactions. Other potential tactics involve hydration or reassessment of the current algorithm for calculating blood volume that uses height and weight.18 During the 40 years since this formula was derived, American's body mass index has changed. Adipose tissue, proportionally, has less blood volume per kilogram suggesting a new approach is needed for determining blood volume. Baroreceptor sensitivity changes in relationship to donor's age present another research opportunity. Thus, hemovigilance studies provide multiple opportunities for generating testable hypotheses for spawning robust decision making data. At this time, we believe that the societal benefits of making blood donation opportunities available to high school students (16- to 18-year-olds) outweigh the risks. Also, we recognize the potential inaccuracy of total blood volume estimations that may result in collection of more than 15 percent of a donor's total blood volume, especially with the use of 500-mL blood containers plus an additional 25 to 35 mL for blood testing. For this reason, at the Community Blood Center, we implemented many of the above-mentioned procedures and raised the minimal weight requirement to 115 lbs. Others may choose alternative approaches to changing eligibility criteria that take into account total blood volume normograms. It is important that we monitor the effectiveness of these interventions to gauge progress in enhancing donation safety.