Temporal relationship between haemodynamic changes and activation of closed-loop stimulation during a tilt-induced vasovagal syncope.

AIMS: A dual-chamber pacemaker with closed-loop stimulation (CLS) mode is effective in reducing syncopal recurrences in patients with asystolic vasovagal syncope (VVS). In this study, we explored the haemodynamic and temporal relationship of CLS during a tilt-induced vasovagal reflex. METHODS AND RESULTS: Twenty patients underwent a tilt test under video recording 3.9 years after CLS pacemaker implantation. Three patients were excluded from the analysis because of no VVS induced by the tilt test (n = 1) and protocol violation (n = 2). In 14 of the remaining 17 patients, CLS pacing emerged during the pre-syncopal phase of circulatory instability when the mean intrinsic heart rate (HR) was 88 ± 12 b.p.m. and systolic blood pressure (SBP) was 108 ± 19 mmHg. The CLS pacing rate thereafter rapidly increased to 105 ± 14 b.p.m. within a median of 0.1 min [inter-quartile range (IQR), 0.1-0.7 min] when the SBP was 99 ± 21 mmHg. At the time of maximum vasovagal effect (syncope or pre-syncope), SBP was 63 ± 17 mmHg and the CLS rate was 95 ± 13 b.p.m. The onset of CLS pacing was 1.7 min (IQR, 1.5-3.4) before syncope or lowest SBP. The total duration of CLS pacing was 5.0 min (IQR, 3.3-8.3). Closed-loop stimulation pacing was not observed in three patients who had a similar SBP decrease from 142 ± 22 mmHg at baseline to 69 ± 4 mmHg at the time of maximum vasovagal effect, but there was no significant increase in HR (59 ± 1 b.p.m.). CONCLUSION: The reproducibility of a vasovagal reflex was high. High-rate CLS pacing was observed early during the pre-syncopal phase in most patients and persisted, although attenuated, at the time of maximum vasovagal effect. REGISTRATION: ClinicalTrials.gov identifier: NCT06038708.

Prevention strategies for vasovagal reaction in whole blood donors: A quadri-armed randomised control trial.

INTRODUCTION: Vasovagal reaction (VVR) is a frequently encountered generalised donor adverse reaction, associated with donor deterrence towards future donation. Several mitigation strategies for prevention of VVR were tried but still not standardised. This quadri-armed randomised study evaluated the utility of water ingestion, applied muscle tension (AMT) and combination of both in preventing the VVR among blood donors. METHODS: A quadri-armed randomised controlled trial was performed on 4320 whole blood donors. Blood donors of 18-65 years of age were randomised into four groups based on the interventions performed i.e., control with no intervention (Group 1, n = 1081), water ingestion (Group 2, n = 1082), AMT (Group 3, n = 1070) and combined intervention (Group 4, n = 1087). VVR during and immediately after blood donation were observed along with assessment of risk factors in blood donors and the effectiveness of interventions were analysed. RESULTS: The incidence of VVR observed 1.6% in our study, with the highest occurrence in the control group (2.5%) and the lowest in the combined intervention group (0.9%). Multivariable logistic regression revealed that the control group donors faced a 1.38-fold greater risk of VVR compared to those receiving interventions (OR: 1.38, 95% CI: 1.10-1.75). Other risk factors included younger age (OR: 1.5, 95% CI: 1.05-2.17), first-time donation (OR: 5.7, 95% CI: 1.66-5.74), prior history of VVR (OR: 2.5, 95% CI: 10.4-101.52). DISCUSSION/CONCLUSION: The combined approach of water ingestion and AMT proved significantly more effective in VVR prevention compared to individual interventions.

The efficacy of non-pharmacological and non-pacing therapies in preventing vasovagal syncope: Tilt training, physical counter pressure maneuvers, and yoga - A systematic review and meta-analysis.

BACKGROUND: Vasovagal syncope (VVS) is a prevalent condition characterized by a sudden drop in blood pressure and heart rate, leading to a brief loss of consciousness and postural control. Recurrent episodes of VVS significantly impact the quality of life and are a common reason for emergency department visits. Non-pharmacological interventions, such as tilt training, physical counter pressure maneuvers, and yoga, have been proposed as potential treatments for VVS. However, their efficacy in preventing VVS remains uncertain. METHODS: A systematic review and meta-analysis were conducted following PRISMA guidelines. PubMed, Web of Science, and Embase were searched up to March 2023 for randomized controlled trials comparing non-pharmacological interventions with control in preventing VVS recurrence. The primary outcome was the recurrence rate of VVS episodes. RESULTS: A total of 1130 participants from 18 studies were included in the meta-analysis. The overall mean effect size for non-pharmacological interventions versus control was 0.245 (95 % CI: 0.128-0.471, p-value <0.001). Subgroup analysis showed that yoga had the largest effect size (odds ratio 0.068, 95 % CI: 0.018-0.250), while tilt training had the lowest effect size (odds ratio 0.402, 95 % CI: 0.171-0.946) compared to control. Physical counter pressure maneuvers demonstrated an odds ratio of 0.294 (95 % CI: 0.165-0.524) compared to control. CONCLUSION: Non-pharmacological interventions show promise in preventing recurrent VVS episodes. Yoga, physical counter pressure maneuvers, and tilt training can be considered as viable treatment options. Further research, including randomized studies comparing pharmacological and non-pharmacological approaches, is needed to evaluate the safety and efficacy of these interventions for VVS treatment.

Interventions aimed to increase average 24-h systolic blood pressure reduce blood pressure drops in patients with reflex syncope and orthostatic intolerance.

AIMS: Systolic blood pressure (SBP) drops recorded by 24-h ambulatory blood pressure (BP) monitoring (ABPM) identify patients with susceptibility to reflex syncope and orthostatic intolerance. We tested the hypothesis that treatments aimed to increase BP (reassurance, education, and lifestyle measures plus pharmacological strategies) can reduce SBP drops. METHODS AND RESULTS: This was a multicentre, observational proof-of-concept study performed in patients with reflex syncope and/or orthostatic intolerance and with SBP drops on a screening ABPM. Among 144 eligible patients, 111 underwent a second ABPM on average 2.5 months after start of treatment. Overall, mean 24-h SBP increased from 114.1 ± 12.1 to 121.4 ± 14.5 mmHg (P < 0.0001). The number of SBP drops <90 and <100 mmHg decreased by 61%, 46% during daytime, and by 48% and 37% during 24-h period, respectively (P < 0.0001 for all). The dose-response relationship between difference in 24-h average SBP increase and reduction in number of SBP drops reached a plateau around ∼15 mmHg increase of 24-h SBP. The reduction in SBP drop rate was consistent and significant in patients who underwent deprescription of hypotensive medications (n = 44) and in patients who received BP-rising drugs (n = 67). CONCLUSION: In patients with reflex syncope and/or orthostatic intolerance, an increase in average 24-h SBP, regardless of the implemented strategy, significantly reduced the number of SBP drops and symptom burden. A 13 mmHg increase in 24-h SBP appears to represent the optimal goal for aborting the maximal number of SBP drops, representing a possible target for future interventions. ClincalTrials.gov identifier: NCT05729724.

Serotonin reuptake inhibition for the prevention of vasovagal syncope: a systematic review and meta-analysis.

PURPOSE: Vasovagal syncope is a common clinical condition that lacks effective medical therapies despite being associated with significant morbidity. Current guidelines suggest that serotonin-specific reuptake inhibitors might suppress vasovagal syncope but supporting studies have been small and heterogenous. The purpose of this study was to evaluate the efficacy of serotonin-specific reuptake inhibitors to prevent syncope in patients with recurrent vasovagal syncope by conducting a systematic review and meta-analysis of published studies. METHODS: Relevant randomized controlled trials were identified from the MEDLINE and Embase databases without language restriction from inception to August 2022, and ClinicalTrials.gov. All studies were conducted in clinical syncope populations and compared the benefit of serotonin versus placebo. Weighted relative risks were estimated using random effects meta-analysis techniques. RESULTS: Three studies (n = 204) met inclusion criteria. Patients were 42 ± 13 years of age and 51% female. Serotonin-specific reuptake inhibitors were found to substantially reduce the likelihood of a patient having at least one recurrence of vasovagal syncope [relative risk (RR) 0.34 (0.20-0.60), p < 0.01] with minimal between-study heterogeneity (I2 = 0%, p = 0.67). Serotonin-specific reuptake inhibitors in two reports provided significant protection against clinical presyncope [RR 0.43 (0.24-0.77), p < 0.01], with minimal between-study heterogeneity (I2 = 0%, p = 0.80). CONCLUSIONS: Serotonin-specific reuptake inhibitors may be effective in preventing syncope induced by head-up tilt testing and in syncope in the community in randomized, double-blinded clinical trials.

A new risk predictive scoring system of vasovagal reactions in patients with preoperative autologous blood donation.

BACKGROUND AND OBJECTIVES: Vasovagal response (VVR) is the most common adverse reaction during blood donation and it is the main element for the safety of the patients with preoperative autologous blood donation (PABD). Accurate identification high-risk group is of great significance for PABD. Our study aimed to establish a scoring system based on the nomogram to screen the high-risk population and provide evidence for preventing the occurrence of VVRs. MATERIALS AND METHODS: A number of 4829 patients underwent PABD between July 2017 and June 2020 in the first medical center of Chinese PLA Hospital were recruited, 3387 of whom were included in the training group (70 %; 108 VVRs patients vs 3279 Non-VVRs patients), 1442 were included in the validation group (30 %; 46 VVRs patients vs 1396 Non-VVRs patients). The data were analyzed by univariate and multivariate logistic regression. The nomogram of the scoring system was created by using the RMS tool in R software. RESULTS: Seven variables including BMI, hematocrit, pre-phlebotomy heart rate and systolic blood pressure, history of blood donation, age group and primary disease were selected to build the nomogram, which was shown as prediction model. And the score was 0-1 for BMI, 0-2 for hematocrit, systolic blood pressure, heart rate and no blood donation history, 0-10 for age, 0-3 for primary disease. When the total cutoff score was 11, the predictive system for identifying VVRs displayed higher diagnostic accuracy. The area under the curve, specificity, and sensitivity of the training group were 0.942, 82.41 % and 97.17 %, respectively, whereas those of the validation group were 0.836, 78.26 % and 78.15 %, respectively. CONCLUSION: A risk predictive scoring system was successfully developed to identify high-risk VVRs group form PABD patients that performed well.

Pain associated with intravascular instrumentation reduces orthostatic tolerance and predisposes to vasovagal reactions in healthy young adults without needle phobia: a randomised controlled study.

PURPOSE: Vasovagal syncope (VVS), or fainting, is frequently triggered by pain, fear, or emotional distress, especially with blood-injection-injury stimuli. We aimed to examine the impact of intravenous (IV) instrumentation on orthostatic tolerance (OT; fainting susceptibility) in healthy young adults. We hypothesized that pain associated with IV procedures would reduce OT. METHODS: In this randomised, double-blind, placebo-controlled, cross-over study, participants (N = 23; 14 women; age 24.2 ± 4.4 years) underwent head-up tilt with combined lower body negative pressure to presyncope on three separate days: (1) IV cannulation with local anaesthetic cream (EMLA) (IV + EMLA); (2) IV cannulation with placebo cream (IV + Placebo); (3) sham IV cannulation with local anaesthetic cream (Sham + EMLA). Participants rated pain associated with IV procedures on a 1-5 scale. Cardiovascular (finger plethysmography and electrocardiogram; Finometer Pro), and forearm vascular resistance (FVR; brachial Doppler) responses were recorded continuously and non-invasively. RESULTS: Compared to Sham + EMLA (27.8 ± 2.4 min), OT was reduced in IV + Placebo (23.0 ± 2.8 min; p = 0.026), but not in IV + EMLA (26.2 ± 2.2 min; p = 0.185). Pain was increased in IV + Placebo (2.8 ± 0.2) compared to IV + EMLA (2.0 ± 2.2; p = 0.002) and Sham + EMLA (1.1 ± 0.1; p < 0.001). Orthostatic heart rate responses were lower in IV + Placebo (84.4 ± 3.1 bpm) than IV + EMLA (87.3 ± 3.1 bpm; p = 0.007) and Sham + EMLA (87.7 ± 3.1 bpm; p = 0.001). Maximal FVR responses were reduced in IV + Placebo (+ 140.7 ± 19.0%) compared to IV + EMLA (+ 221.2 ± 25.9%; p < 0.001) and Sham + EMLA (+ 190.6 ± 17.0%; p = 0.017). CONCLUSIONS: Pain plays a key role in predisposing to VVS following venipuncture, and our data suggest this effect is mediated through reduced capacity to achieve maximal sympathetic activation during orthostatic stress. Topical anaesthetics, such as EMLA, may reduce the frequency and severity of VVS during procedures requiring needles and intravascular instrumentation.

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.

Lidocaine Tape Application for 3 Hours Prevents Vasovagal Syncope During Venipuncture: A Case Series.

Vasovagal syncope (VVS) or reflex is usually caused by physical and mental stress-related factors, like pain, anxiety, and fear, and it is one of the most frequent complications during dental treatment. Two patients, both with histories of dental phobia and of VVS during vaccination, venipuncture, and dental treatment with local anesthetics, were scheduled for dental treatment under intravenous (IV) sedation. However, both experienced episodes of VVS that occurred during venipuncture using a 24-gauge indwelling needle. We determined that pain was the main trigger of VVS for these patients and attempted to reduce venipuncture-associated pain using 60% lidocaine tape applied 3 hours before venipuncture at their next dental visits, respectively. Use of the lidocaine tape was successful and permitted comfortable placement of the IV catheter without any onset of VVS.

Pre-donation water and salty snacks to prevent vasovagal reactions among blood donors.

BACKGROUND: Minimizing the risk of vasovagal reactions (VVRs) can prevent donor harms and improve donor return. We report the results of a program to reduce VVR rates. STUDY DESIGN AND METHODS: The program was implemented on June 11, 2017 and consisted in drinking water and eating a salty snack before donating blood, plasma, or platelets. All donations made during the "pre-program period" (October 11, 2015-June 10, 2017) and "post-program period" (June 11, 2017-May 11, 2019) were included. Study outcomes comprised VVRs (any severity) and syncopal VVRs, whether employee- or donor-reported. An interrupted time series (ITS) analysis proxied causality based on the "pre-program trend," the "immediate trend" (i.e., immediately before versus after the program), and the "post-program trend". The relative risk (RR) of VVR (along with confidence intervals [CIs]) was reported, overall and stratified by subgroups based on age, sex, donor type (i.e., first-time versus repeat), and donation type (i.e., whole blood versus apheresis). RESULTS: The monthly VVR rate (any severity) dropped from 4.6% in the pre-program period to 4.3% in the post-program period, and never reached its pre-program level. The ITS analysis revealed a statistically significant and increasing pre-program trend (RR [95% CI] = 1.011 [1.002-1.020]), a statistically significant and decreasing immediate trend (RR [95% CI] = 0.848 [0.743-0.969]), and a non-statistically-significant and stable post-program trend (RR [95% CI] = 0.999 [0.993-1.006]). Similar trends were observed for nearly all high- and low-risk subgroups. No statistically significant trend was observed for syncopal VVRs. DISCUSSION: These results suggest that the herein-described program durably reduced the incidence of VVRs (any severity) by ~15%.

Prevention of Blood Donation-related Vasovagal Response by Applied Muscle Tension: a Meta-analysis.

OBJECTIVE: Vasovagal reaction (VVR) is an adverse reaction to blood donation. Applied muscle tension (AMT) has been reported to reduce the probability of VVR during blood donation; however, the results have been controversial. We therefore conducted a meta-analysis to systematically evaluate the effect of AMT in reducing VVR. METHODS: We searched six major databases using "applied muscle tension" and "blood donation-related vasovagal response" as keywords. Relevant articles published in English or Chinese between 1 January 2000 and 30 June 2021 were included in the analysis. The quality of the included articles was evaluated and publication bias was assessed by forest and funnel plots and by Egger's test. RESULTS: Fifty-one articles were identified, of which six were included according to the pre-defined inclusion and exclusion criteria. A fixed-effects model was adopted for effect size combination and revealed a relative risk of 0.52 (95% confidence interval 0.40 to 0.67). The AMT group was superior to the control in terms of VVR prevention. A funnel plot and Egger's test suggested that the findings were accurate and reliable with low publication bias. CONCLUSION: AMT could effectively reduce VVR during blood donation. Further multicenter studies with large sample sizes are needed to confirm these results.

Vasovagal Reactions during Interventional Pain Management Procedures-A Review of Pathophysiology, Incidence, Risk Factors, Prevention, and Management.

Vasovagal reactions are a benign but common outcome of interventional pain management procedures that can negatively impact patient care, including aborted procedures and fear of future procedures that would otherwise help the patient. Research has been done on the incidence, risk factors, and management of vasovagal reactions resulting from such procedures, but less is known about how to prevent these reactions from occurring. In this paper, we present a literature review of the pathophysiology, incidence, risk factors, prevention, and management of vasovagal reactions during interventional pain management procedures, with an emphasis on the relative lack of research and conflicting advice on preventive measures. We found that moderate sedation and anxiolytics have been used prophylactically to prevent vasovagal reactions, but their side-effect profiles prevent them from being used commonly. Less studied is the prophylactic administration of antimuscarinics and IV fluids, despite the potential benefit of these measures and relatively low side-effect profile. We explore these topics here and offer advice for future research to fill the gaps in our knowledge.

Implementation of supervised physical training to reduce vasovagal syncope recurrence: A randomized controlled trial.

INTRODUCTION: Physical techniques used for the prevention of vasovagal syncope have limited evidence for efficacy. We aimed to evaluate multimodal supervised physical training as a treatment approach. METHODS: In this 1:1 randomized trial, patients with ≥2 episodes of clinically diagnosed vasovagal syncope were included. On top of standard care, the intervention arm performed supervised tilt training and aerobic exercise in six sessions at a cardiac rehabilitation center (three sessions during the first month, and then at 3-month intervals), plus home tilt training. The control arm received standard care with a similar protocol of home tilt training. The primary outcome was time to first syncopal recurrence during 1 year of follow-up. RESULTS: Fifty participants were randomized (mean age: 34.5 ± 14.8 years; 64% female). The rate of syncopal recurrence was 28% and 64% within the intervention and control arms, respectively, with significantly higher syncope-free survival at 1 year in the intervention arm (Log-rank p = .003). The frequency of recurrent syncopal events was significantly lower with physical training (p = .017). Participants in the intervention arm reported significantly higher adherence to the home tilt training program (80% vs. 52%; p = .037). CONCLUSION: Among patients with recurrent vasovagal syncope, a supervised program of tilt training and aerobic exercise reduced syncopal recurrence. Future trials are warranted to further investigate multimodal supervised physical techniques as a therapeutic approach in treating vasovagal syncope.

Midodrine for the prevention of vasovagal syncope: a systematic review and meta-analysis.

AIMS: Vasovagal syncope (VVS) is a common clinical condition that lacks effective medical therapies despite being associated with significant morbidity. Current guidelines suggest that midodrine, a prodrug for an α1-adrenergic receptor agonist, might suppress VVS but supporting studies have utilized heterogeneous methods and yielded inconsistent results. To evaluate the efficacy of midodrine to prevent syncope in patients with recurrent VVS by conducting a systematic review and meta-analysis of published studies. METHODS AND RESULTS: Relevant randomized controlled trials were identified from the MEDLINE, Embase, CENTRAL, and CINAHL databases without language restriction from inception to June 2021. All studies were conducted in clinical syncope populations and compared the benefit of midodrine vs. placebo or non-pharmacological standard care. Weighted relative risks (RRs) were estimated using random effects meta-analysis techniques. Seven studies (n = 315) met inclusion criteria. Patients were 33 ± 17 years of age and 31% male. Midodrine was found to substantially reduce the likelihood of positive head-up-tilt (HUT) test outcomes [RR = 0.37 (0.23-0.59), P < 0.001]. In contrast, the pooled results of single- and double-blind clinical trials (I2 = 54%) suggested a more modest benefit from midodrine for the prevention of clinical syncope [RR = 0.51 (0.33-0.79), P = 0.003]. The two rigorous double-blind, randomized, placebo-controlled clinical trials included 179 VVS patients with minimal between-study heterogeneity (I2 = 0%) and reported a risk reduction with midodrine [RR = 0.71 (0.53-0.95), P = 0.02]. CONCLUSIONS: Midodrine is effective in preventing syncope induced by HUT testing and less, but still significant, RR reduction in randomized, double-blinded clinical trials.

The benefit of cardioneuroablation to reduce syncope recurrence in vasovagal syncope patients: a case-control study.

BACKGROUND: Adequate and effective therapy for resistant vasovagal syncope patients is lacking and the benefit of cardioneuroablation (CNA) in this cohort is still debated. The aim of this study is to assess the long-term effect of CNA versus conservative therapy (CT) in a retrospectively followed cohort. METHODS: A total of 2874 patients underwent head-up tilt test (HUT) and 554 (19.2 %) were reported as positive, with VASIS type 2B response or > 3 s asystole in 130 patients. After exclusion of 29 patients under 18 years and over 65 years of age, 101 patients were included final analysis. Fifty-one patients (50.4%) underwent CNA and 50 (49.6%) patients received CT. After propensity score matching, 19 pairs of patients were successfully matched. The recurrence rate of syncope was compared between groups. RESULTS: During a median follow-up of 22 months (IQR, 13-35), syncope was seen in 12 (11.8%) cases. In the 19 propensity-matched patients, recurrent syncope was observed in 8 patients in the CT group and in 2 patients in the CNA group, respectively. In mixed effect Cox regression analysis, CNA was associated with less syncope recurrence risk at follow-up (HR 0.23, 95% CI 0.03-0.99, p = 0.049). The 4-year Kaplan-Meier syncope free rate was 0.86 (95% CI, 0.63-1.00) for CNA group and 0.50 (95% CI, 0.30-0.82) for CT group in the matched cohort. CONCLUSIONS: In highly selected patients with HUT-induced cardioinhibitory response, CNA is associated with a significant reduction in syncope recurrence during follow-up when compared to CT.

An intervention study for the prevention of vasovagal reactions and evaluating donors' experience: Analysis of donors' return for subsequent donation.

BACKGROUND AND OBJECTIVES: The EPISoDe (Experience Success in Donation) study investigated the effect of interventions on self-reported vasovagal reactions (VVRs) in first-time and novice (second to fourth donation) whole blood donors aged ≤30 years, demonstrating a 23% reduction of VVR from water drinking shortly before donation in the novice donors. Because donation experience and complications affect donor retention, we analysed intervention group donors' return for subsequent donation, a predefined secondary outcome. MATERIALS AND METHODS: The interventions were as follows: 330 ml water, 500 ml water, ball squeezing before phlebotomy (placebo) and a control group. All donors received an online questionnaire about their experience within a week after donation. In the Netherlands, eligible donors are invited at least yearly depending on hospitals' needs. We analysed attendances within 421 days through return percentages and binomial logistic regression. RESULTS: Of the 8300 EPISoDe participants, 6538 (78.8%) returned within 421 days. Return did not differ between the two water groups, whereas odds for return were significantly higher in both water and placebo intervention donors compared to the control group (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.00-1.29 and 1.22, 1.05-1.43, respectively) after adjustment for occurrence of VVR, unsuccessful collection, gender and donation history. Staff-recorded or self-reported VVR at index donation was associated with reduced odds for return (OR 0.47, 95% CI 0.37-0.60 and OR 0.53, 95% CI 0.46-0.61, respectively). CONCLUSION: In this cohort of younger inexperienced blood donors, 78.8% returned for subsequent donation. Donors who received an active study intervention, either water or placebo, were more likely to return than control group donors.

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.

A Device to Reduce Vasovagal Syncope in Blood Donors.

Vasovagal Syncope (VVS), or the transient loss of consciousness is the most widely recognized reason for syncope. (VVS), is a typical dysfunction of the autonomic nervous system. There are various factors which can influence the syncope. The major classification of the syncope are reflex(neurally mediated) syncope, syncope due to orthostatic hypertension, Cardiac syncope(cardiovascular). The vasovagal syncope is the part of reflex (neurally mediated)syncope, there are various cause of vasovagal reactions but in blood donation it is mediated due to the pooling of blood at calf muscles. Such near syncope incidence while donating the blood or after donation hampers the future motivation for blood donation of the donors. In this paper, we developed an electronic massager for calf muscles that can reduce the risk of VVS. It has a programmable circuit which can control the vacuum pump so that it can inflate and deflate the cuffs synergistically. The massager can relax the blood donor thereby reducing apprehension prior to blood donation and thus diverting from the trigger of Phlebotomy and improve peripheral blood circulation thereby improving venous return to the heart. This is expected to reduce the risk of VVS.