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donation anxiety or increased heart rate. Unlike pre-donation water loading and AMT, the effect of caffeine administration pre-donation has not been more broadly considered. As such, further research is needed to determine if caffeine may provide benefit to blood donors in preventing VVRs. Psychological strategies In comparison to the empirical literature focused on pre-donation water loading and AMT, relatively few studies have considered the psychological aspects of donation and their relationship to vasovagal symptoms. Where interventions have been evaluated, these have focused primarily on emotion regulation to reduce stress or anxiety through providing distraction or social support during the procedure. For example, Bonk and colleagues (2001) investigated the efficacy of audiovisual distraction for first-time donors who were classified as having either a monitoring (attention to the situation) or blunting (distraction, denial or reinterpretation of what is occurring) coping style. Blunting donors who received distraction that matched their coping style had significantly lower self-reported vasovagal symptoms than participants in the no-treatment control condition. In terms of social support, Hanson and France (2009) conducted a small randomised controlled trial with novice donors (n=65) to explore the effects of pairing donors with a research assistant who had been trained to be supportive. Donors receiving this form of in situ social support selfreported lower levels of vasovagal reactions and stronger intentions to donate again than those in the control condition. Hanson and France (2009) suggested, drawing on the cardiovascular This article is protected by copyright. All rights reserved. 15 reactivity literature, that the presence of a calming support person (or experienced phlebotomist; Stewart et al. 2006) may reduce vasovagal symptoms through attenuating stress reactions. In addition, trials of physiological interventions have provided some evidence of the beneficial effects of anxiety and VVR reduction. Ditto and colleagues (2007) found that donors assigned to their placebo control condition in which donors were asked to focus attention on their nondonating arm while using upper-body muscle tension exercises reported less severe vasovagal symptoms and less anxiety compared to donors in the business-as-usual condition. Further, Holly and colleagues (2012) found in a randomised trial, that engaging in AMT in the waiting area significantly reduced anxiety and self-reported vasovagal symptoms in donors compared to the business-as-usual group. As these effects have emerged as artefacts of trials designed to assess the efficacy of other interventions, the precise mechanism through which AMT exercises in the waiting area reduced vasovagal symptoms remains unidentified. As such, further research is need to determine precisely how physiological and psychological interventions can be effectively implemented to reduce the stress and anxiety that (some) donors experience, and how these interventions map through to reductions in the experience of vasovagal symptoms. Although a large number of intervention studies have evaluated the impact of using physiological and psychological methods to prevent VVRs and/or vasovagal symptoms, questions with regard to the efficacy of these techniques still remain. Proposed methods of prevention have not been standardised in evaluations (e.g., AMT) and outcomes have been inconsistently assessed, with This article is protected by copyright. All rights reserved. 16 more techniques showing benefit in relation to self-reported vasovagal symptoms than phlebotomist-registered reactions. However, the latter may not be a major concern given that self-reported vasovagal symptoms are a stronger predictor of return behaviour (France et al. 2004). Further, what is not yet clear is the impact of VVR prevention techniques on reducing VVRs in plasmapheresis and plateletpheresis donors. While rates of VVR are lower in apheresis donors (Crocco et al. 2009), all published intervention trials have focused solely on WB donors. Finally, little is known about how to successfully implement VVR prevention strategies in routine blood collection practices and whether any documented beneficial effect on VVR reduction is maintained outside the controlled environment of an efficacy trial. Managing the impact of vasovagal reactions Whilst there is a strong focus in transfusion medicine research on identifying risk factors for VVRs and how to effectively prevent these reactions, comparatively little research has been conducted on how to best manage the physiological and psychological impact of experiencing a VVR. However, it is clear that once a donor begins to experience a VVR, both the donor and phlebotomist play a key role in managing the donor’s reaction. In blood

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