Evaluation of interventions to prevent vasovagal reactions among whole blood donors: rationale and design of a large cluster randomised trial

BACKGROUND

Vasovagal reactions (VVRs) are the most common acute complications of blood donation. Responsible for substantial morbidity, they also reduce the likelihood of repeated donations and are disruptive and costly for blood services. Although blood establishments worldwide have adopted different strategies to prevent VVRs (including water loading and applied muscle tension [AMT]), robust evidence is limited. The Strategies to Improve Donor Experiences (STRIDES) trial aims to reliably assess the impact of four different interventions to prevent VVRs among blood donors.

METHODS

STRIDES is a cluster-randomised cross-over/stepped-wedge factorial trial of four interventions to reduce VVRs involving about 1.4 million whole blood donors enrolled from all 73 blood donation sites (mobile teams and donor centres) of National Health Service Blood and Transplant (NHSBT) in England. Each site ("cluster") has been randomly allocated to receive one or more interventions during a 36-month period, using principles of cross-over, stepped-wedge and factorial trial design to assign the sequence of interventions. Each of the four interventions is compared to NHSBT's current practices: (i) 500-ml isotonic drink before donation (vs current 500-ml plain water); (ii) 3-min rest on donation chair after donation (vs current 2 min); (iii) new modified AMT (vs current practice of AMT); and (iv) psychosocial intervention using preparatory materials (vs current practice of nothing). The primary outcome is the number of in-session VVRs with loss of consciousness (i.e. episodes involving loss of consciousness of any duration, with or without additional complications). Secondary outcomes include all in-session VVRs (i.e. with and without loss of consciousness), all delayed VVRs (i.e. those occurring after leaving the venue) and any in-session non-VVR adverse events or reactions.

DISCUSSION

The STRIDES trial should yield novel information about interventions, singly and in combination, for the prevention of VVRs, with the aim of generating policy-shaping evidence to help inform blood services to improve donor health, donor experience, and service efficiency.

TRIAL REGISTRATION

ISRCTN: 10412338. Registration date: October 24, 2019.

SARS-CoV-2 vaccine-associated-tinnitus: A review

The global vaccination drive against severe acute respiratory syndrome coronavirus-2 is being pursued at a historic pace. Unexpected adverse effects have been reported following vaccination, including thrombotic thrombocytopenia, myocarditis, amongst others. More recently, some cases of tinnitus are reported post-vaccination. According to the Vaccine Adverse Events Reporting System (VAERS), 12,247 cases of coronavirus post-vaccination tinnitus have been reported till September 14, 2021. To the best of our knowledge, this is the first review evaluating any otologic manifestation following vaccine administration and aims to evaluate the potential pathophysiology, clinical approach, and treatment. Although the incidence is infrequent, there is a need to understand the precise mechanisms and treatment for vaccine-associated-tinnitus.

Social Contagion of Vasovagal Symptoms in Blood Donors: Interactions With Empathy

BACKGROUND

Vasovagal reactions (VVRs) are commonly experienced in medical situations such as blood donation. Many believe that psychosocial contagion can contribute to the development of VVRs, but this is largely clinical lore.

PURPOSE

The goal of the present investigation was to examine the physiological effects of observing another experience a reaction, focusing on the potential moderating effects of empathy.

METHODS

This study was part of a randomized controlled trial of behavioral techniques on the prevention of VVRs in blood donors. The sample was composed of 530 healthy university students. Measures of symptoms were obtained with the Blood Donation Reactions Inventory (BDRI) and through observation. Physiological variables were measured using respiratory capnometry and a digital blood pressure monitor. The Affective and Cognitive Measure of Empathy was administered to 230 participants.

RESULTS

Donors who witnessed another experiencing a reaction were more likely to spontaneously report symptoms during the blood draw, to be treated for a reaction, to score higher on the BDRI, and to exhibit smaller compensatory heart rate increases. Donors with higher affective empathy reported more symptoms, exhibited hyperventilation, and were more likely to be treated. Donors with higher cognitive empathy were less likely to require treatment if they witnessed a reaction.

CONCLUSION

These results suggest that psychosocial contagion of physical symptoms can occur. The moderating effects of empathy differed depending on the subtype of empathy. Perhaps a better cognitive understanding of how other people are feeling functions as a coping response, whereas feeling sympathetic about others' distress increases one's own.

The vasovagal reaction experience among blood donors: A qualitative study of factors that affect donor return

RATIONALE

Blood collection agencies face ongoing challenges in retaining voluntary donors to meet the demand for blood and blood-related products by healthcare services. A known deterrent to continued blood donation is the experience of a vasovagal reaction (VVR). However, there has been little research into donors' experiences of these reactions and the factors that influence their decision to return, which is essential information to inform strategies to improve donor return.

OBJECTIVE

The aim of this paper was to explore blood donor views and experiences of a VVR, with a particular interest in how the reaction influenced their return behaviour, using the Transactional Model of Stress and Coping.

METHODS

We conducted 34 semi-structured in-depth interviews between February and April 2018 with a sample of Australian donors who had experienced a VVR in the last seven days. Transcripts were analysed using the Framework Method.

RESULTS

The VVR elicited various emotional responses, which appeared to be influenced by social support, being aware of the possibility of experiencing a VVR, or the donation outcome. In turn, the VVR experience affected intentions to return, with those who reported more positive experiences expressing stronger intentions. Further, donors felt more likely to return if they perceived their risk of a recurrent event as low and if they were able to identify appropriate problem and emotion-focused coping strategies.

CONCLUSION

This article provides novel insights into possible ways to encourage blood donor return following a VVR.

Beyond Description: The Predictive Role of Affect, Memory, and Context in the Decision to Donate or Not Donate Blood

Background

Research on the recruitment and retention of blood donors has typically drawn on a homogeneous set of descriptive theories, viewing the decision to become and remain a donor as the outcome of affectively cold, planned, and rational decision-making by the individual. While this approach provides insight into how our donors think about blood donation, it is limited and has not translated into a suite of effective interventions. In this review, we set out to explore how a broader consideration of the influences on donor decision-making, in terms of affect, memory, and the context in which donation takes place, may yield benefit in the way we approach donor recruitment and retention.

Summary

Drawing on emerging research, we argue for the importance of considering the implications of both the positive and the negative emotions that donors experience and we argue for the importance of directly targeting affect in interventions to recruit nondonors. Next, we focus on the reconstructed nature of memory and the factors that influence what we remember about an event. We discuss how these processes may impact the retention of donors and the potential to intervene to enhance donors' recollections of their experiences. Finally, we discuss how our focus on the individual has led us to neglect the influence of the context in which donation takes place on donor behavior. We argue that the amassing of comprehensive large data sets detailing both the characteristics of the individuals and the context of their giving will ultimately allow for the more effective deployment of resources to improve recruitment and retention.

Key Messages

In suggesting these directions for future research, our want is to move beyond the ways in which we have traditionally described blood donation behavior with the aim of improving our theorizing about donors while improving the translational value of our research.