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Background: Fear of blood donation is implicated in vasovagal reactions, donor recruitment, and retention. This study examined the extent to which fear among donors is associated with various donor outcomes in an Australian sample, and whether fear can be addressed on-site to reduce adverse reactions and improve the donation experience.Study Design and Methods: Six hundred and sixty-four donors (age M = 33.4, SD = 12.7; 55% female) participated in a two-center, pragmatic, parallel group, individually randomized controlled trial. Following donor registration and consent, whole-blood (n = 539) and plasma (n = 125) donors were assigned to one of four Conditions: control; fear assessment; fear assessment + brochure; fear assessment + brochure + tailored conversation focused on any self-reported fear and coping strategies. Post-donation questionnaires assessed the donors' experience including positive support, donor self-efficacy, anxiety, fear, venipuncture pain, and vasovagal reactions.Results: Fear among donors predicted higher venipuncture pain, post-donation anxiety, and vasovagal reactions and remained significant after controlling for other established predictors (i.e., total estimated blood volume, age, sex, and donation experience). Mediational analyses showed that exposure to brochures (with or without the tailored conversation) was associated with less pain, with this effect mediated by donor perceptions of more positive support. Venipuncture pain was also associated with vasovagal reactions, reduced likelihood of return within 6 months, and less satisfaction with the donation experience.Conclusion: The current results underline the importance of interventions to address fear among both whole-blood and plasma donors to secure the safety and well-being of donors and the blood supply. [ABSTRACT FROM AUTHOR]

Background and Objectives: The vasovagal response demonstrates a unique form of stress response, common in medical settings yet provoked by a variety of blood-injury-injection stimuli. This study aimed to better understand the psychophysiological mechanisms of the vasovagal response..Methods: 16 undergraduates with and 42 without a self-reported history of fainting watched five 3-5 min videos with different emotional content. One documentary clip (Neutral condition) described a campus environmental project while another (Blood/Injury) depicted portions of an open heart surgery. Three additional clips were also used, including Medical, Threat, and Contamination stimuli. Vasovagal symptoms and physiological variables were assessed during each video.Results: As predicted, while the disgust-related stimuli (Blood/Injury, Medical, Contamination) were associated with generally lower heart rate, the Blood/Injury video produced the highest symptoms and the only significant difference between previous fainters and non-fainters. The physiological measures also revealed that participants with a fainting history experienced higher stroke volume and lower systolic blood pressure throughout, as well as several main effects of video.Limitations: An additional decrease in systolic blood pressure and respiration produced by watching the Blood/Injury video may have been sufficient to trigger symptoms in some, though results also suggest that systemic variables do not entirely explain susceptibility to symptoms. More careful evaluation of regional blood flow may be required.Conclusions: Participants who had previously experienced strong vasovagal responses displayed what appeared to be an anticipatory response to the Blood/Injury video. Finally, disgust stimuli may reduce heart rate but do not appear to contribute to vasovagal symptoms. [ABSTRACT FROM AUTHOR]

Keywords: Nocturnal syncope; Neurally mediated syncope; Gastrointestinal; Loss of consciousness EN Nocturnal syncope Neurally mediated syncope Gastrointestinal Loss of consciousness 5 6 2 03/09/22 20220201 NES 220201 Vasovagal syncope is conventionally defined as a neurally mediated reflex triggered by central hypovolemia, associated with vasodilation of arterial and venous beds and bradycardia. At the risk of being pedantic, it remains unclear whether sleep syncope is true syncope, or whether the experience is possibly better described as nocturnal syncope because the predominantly abdominal symptoms are upon wakening, and syncope can obviously only occur once conscious. [Extracted from the article]

The vasovagal response (VVR) is a common medical problem, complicating and deterring people from various procedures. It is an unusual stress response given the widespread decreases in physiological activity. Nevertheless, VVR involves processes similar to those observed during episodes of strong emotions and pain. We hypothesized that heightened perceived control would reduce symptoms of VVR. Eighty-two young adults were randomly assigned to perceived control or no perceived control conditions during exposure to a stimulus video of a mitral valve surgery, known to trigger VVR in non-medical personnel. Perceived control was manipulated by allowing some participants to specify a break time, though all received equivalent breaks. Outcomes included subjective symptoms of VVR, anxiety, blood pressure, heart rate, and other measures derived from impedance cardiography. Compared to participants with perceived control, participants with no perceived control reported significantly more vasovagal symptoms and anxiety, and experienced lower stroke volume, cardiac output, and diastolic blood pressure. Participants who were more fearful of blood were more likely to benefit from perceived control in several measures. Perceived control appears to reduce vasovagal symptoms. Results are discussed in terms of cognition and emotion in VVR. [ABSTRACT FROM AUTHOR]

This study examined autonomic and hemodynamic processes associated with the development of naturally occurring vasovagal responses. Data from a study assessing the physiological correlates of an intervention to reduce vasovagal responses in blood donors were examined ( Ditto et al., 2009 ). Ninety-eight participants were assigned randomly to groups that either practiced applied tension or not. Dependent variables included ratings of vasovagal symptoms, heart rate, blood pressure, and other parameters derived from ambulatory impedance cardiography. Participants who subsequently experienced vasovagal symptoms had a lower ratio between low and high frequency components (LF/HF HRV) of heart rate variability (HRV) before blood donation, suggesting lower sympathetic nervous system activity. They also showed sharper decreases in total peripheral resistance and lower respiration rates. The results suggest that vasovagal reactions that begin during anticipation of a medical procedure may be characterized by an inhibitory process from the outset and do not support the belief that reactions follow a diphasic pattern. [ABSTRACT FROM AUTHOR]

Vasovagal reactions ( VVR) are common, complicating and deterring people from various medical procedures. A recent perspective ( R. R. Diehl, ) suggests that VVR developed from the adaptive process of hemorrhagic fainting, perhaps as a means of preparing for anticipated blood loss. The primary goal of this study was to compare vasovagal symptoms during intravenous-injection and blood-draw videos. Sixty-two young adults watched the videos. Vasovagal symptoms were assessed with self-report, blood pressure, and heart rate variability. As predicted, participants reported more vasovagal symptoms and anxiety following the blood-draw video. Sympathetic nervous system activity (low- to high-frequency ratio) decreased during both videos but significantly more during the blood-draw video, although this could be reversed by the Applied Tension technique. Results are discussed in terms of the relevance of specific stimuli and emotions in VVR. [ABSTRACT FROM AUTHOR]