A case-controlled multicenter study of vasovagal reactions in blood donors: influence of sex, age, donation status, weight, blood pressure, and pulse

BACKGROUND: Vasovagal reactions occur in a small, but significant number of blood donors. These reactions may decrease return donation and disrupt blood collection activities. The purpose of this study was to define the contributory role of sex, age, weight, blood pressure, and pulse in vasovagal reactions with syncope in blood donors. STUDY DESIGN AND METHODS: A retrospective case-control study involved 1890 blood donors with syncope from three large United States blood centers during 1994 and 1995. Case controls and random population controls were used in a logistic regression analysis to determine the significance of individual variables to syncopal reactions. RESULTS: Female donors, young donors, first-time donors, low-weight donors, and donors with low predonation blood pressure had higher absolute donation reaction rates than other donors. When each variable was adjusted for other variables by regression analysis, age, weight, and donation status (first-time or repeat donor) were significant (p<0.0001), and sex, predonation blood pressure, and predonation pulse were not. The most important variables, in descending order, were age, weight, and donation status (first-time or repeat donor). CONCLUSIONS: Donation-related vasovagal syncopal reactions are a multifactorial process determined largely by age, weight, and first-time donor status.     

Do reactions after whole blood donation predict syncope on return donation?

BACKGROUND: Adverse reactions after whole blood donation reduce the likelihood of a subsequent donation. Still, many donors return to give blood even after experiencing a reaction. Consequently, we evaluated the risk of recurrent syncope among returning donors. STUDY DESIGN AND METHODS: Allogeneic whole blood donors in 2009 who had vasovagal‐type reactions including syncope were evaluated for return donation within 12 months and subsequent reactions, based on donation status (novice [first‐time] or active [repeat]) or age at index donation. RESULTS: Syncope after a first whole blood donation significantly reduced the frequency of return donation (18%), compared to either presyncopal symptoms (27%; p < 0.0001) or no reaction (35%; p < 0.0001). Among novice donors who returned to donate, syncope was more likely among donors who had any reaction (0.8%) or syncope (3.5%) at their first donation, compared to donors who had no reaction (0.3%; p < 0.0001). Syncope at a first donation identified only 2% (19 of 1062) of syncopal reactions among returning donors. For active, repeat donors who experienced syncope in 2009, a history of prior reactions had no effect on the likelihood of return donation or recurrent syncope. CONCLUSION: Donation experience strongly influences the likelihood of return donation and the risk of subsequent reactions, but a prior reaction after whole blood donation does not reliably predict recurrent syncope among returning donors.     

The value of pre-donation pulse assessment for apheresis donors

Objectives: During apheresis, donors have up to 6·5 L of blood processed and receive citrated plasma during the return cycle. It is of concern that a donor with an unrecognised significant cardiac abnormality might therefore be put at further risk during apheresis. Background: Apheresis donors with cardiac abnormalities may be at increased risk of severe adverse reactions as a result of repeated volume loss or the adverse effect of citrate anticoagulant on cardiac contractility as the result of reduction in ionised calcium. An abnormal rate or rhythm may indicate a cardiac abnormality. Methods: At two donation centres between May 2001 and April 2009, the pulse rate and rhythm of every donor was measured before each apheresis procedure they underwent. Donors with a pulse rate outside the range 50–100 beats per minute and/or pulse irregularity were deferred from donation and referred to their general practitioner (GP). Results: Data from 3945 apheresis donors (3874 platelet donors, 71 plasma donors, 3595 males, 350 females) were reviewed. Two hundred thirty‐eight donors (6%) were identified as having abnormal pulses and were referred to their GP. Eighty‐one donors had bradycardia, 16 had tachycardia and 141 had an irregular pulse. Fifteen of the 3945 donors (0·4%) were found to have significant cardiac disease and withdrawn from the donor panel. Conclusions: By simple monitoring, donors who may be at increased risk from the apheresis procedure can be identified. By performing pre‐donation pulse assessment of all apheresis donors, we fulfil our medicolegal duty by not putting donors at avoidable risk.     

Moderate and severe reactions in blood donors

During the period April 1985 to March 1986, 217 blood donors were found to have moderate (syncopal) to severe (convulsive) reactions. This population was compared to 5630 randomly selected donors who did not have reactions. An examination of demographic, physical, and societal/emotional factors was conducted to determine if any were predictive of reactions in donors. The results of the research supported the hypothesis that first-time donors have a higher frequency of reactions (1.7%) than do repeat donors (0.19%). A review of the above predictive factors documented that, with regard to demographic factors, 1) the number of prior donations was inversely proportional to the risk of reaction; 2) the gender of the donor was not predictive; and 3) youth was a predictor of reactions. An analysis of the physical factors revealed that donors who reacted were of lower weight (mean, 153.7 lb) than those who did not (mean, 166.4 lb) and that systolic blood pressure was slightly lower in the group with reactions. Although the difference was significant (3 torr), it was not thought to be significant clinically. In a comparison of a group with systolic blood pressure ranging from 80 to 100 torr and a group with systolic blood pressure ranging from 120 to 140 torr, the first group had a 70-percent higher risk of reaction. Finally, with regard to the last category of societal or emotional factors, the research demonstrates 1) that the ingestion of caffeinated beverages was associated with a reduced risk of reactions; 2) that the food intake of donors who reacred was significantly different from that of those who had no reaction, but this difference was not thought to be clinically significant; and 3) that the duration between registration and the onset of phlebotomy was directly predictive of reaction status. The research indicates that first-time donor status and several specific demographic, physical, and societal or emotional factors are predictors of donor reactions.     

Adverse reactions and other factors that impact subsequent blood donation visits

BACKGROUND: The importance of adverse reactions in terms of donor safety recently has received significant attention, but their role in subsequent donation behavior has not been thoroughly investigated. STUDY DESIGN AND METHODS: Six REDS‐II blood centers provided data for this analysis. Summary minor and major adverse reaction categories were created. The influence of adverse reactions on donation was examined in two ways: Kaplan‐Meier curves were generated to determine the cumulative pattern of first return, and adjusted odds ratios (AORs) for demographic and other factors positively and negatively associated with return were estimated using multivariable logistic regression. RESULTS: Donors who had major reactions had longer times to return than donors with minor or no reactions. The AOR of returning for donors with major reactions was 0.32 (95% confidence interval [CI], 0.28‐0.37) and with minor reactions 0.59 (95% CI, 0.56‐0.62) when compared to donors who did not have reactions. Conversely, the most important factors positively associated with return were the number of donations in the previous year and increasing age. Subsequent return, whether a major, minor, or no reaction occurred, varied by blood center. Factors that are associated with the risk of having adverse reactions were not substantial influences on the return after adverse reactions. CONCLUSION: Having an adverse reaction leads to significantly lower odds of subsequent donation irrespective of previous donation history. Factors that have been associated with a greater risk of adverse reactions were not important positive or negative predictors of return after a reaction.     

Adverse effects in blood donors after whole-blood donation: a study of 1000 blood donors interviewed 3 weeks after whole-blood donation

BACKGROUND: There are no reports in the transfusion medicine literature that describe adverse reactions and donor arm injuries after whole-blood donation based on solicited information. STUDY DESIGN AND METHODS: The present study solicited adverse reaction and donor arm injury information from 1000 randomly selected whole-blood donors approximately 3 weeks after the whole-blood donation. Two 16-gauge phlebotomy needles in use were also compared. RESULTS: Thirty-six percent of the donors had one or more adverse effects (AEs). The most common systemic AEs were fatigue (7.8%), vasovagal symptoms (5.3%), and nausea and vomiting (1.1%). The most common arm findings were bruise (22.7%), arm soreness (10.0%), and hematoma (1.7%). Men were half as likely as women to have an AE (23% AE vs. 48% AE, p < 0.0001). Repeat blood donors had fewer AEs than first-time blood donors (36% AE vs. 47% AE, p < 0.007), and African-American donors had numbers of AEs similar to those of Caucasian donors (31% AE vs. 38% AE, p = 0.30). The two phlebotomy needles did not differ in causing blood donor AEs. CONCLUSION: AEs after donation and complaints may be more common than previously thought. The postdonation interview is a good tool for defining the blood donor's experience. It can also be used to evaluate and potentially improve blood donor safety and comfort.     

Vasovagal reactions in blood donors during or immediately after blood donation

The aim of the study was to estimate the type, incidence and causes of donor adverse reactions during and after blood donation in a Greek Blood Bank, where medical staff is responsible for donor selection. 12 173 blood donors were studied for adverse reactions. One-hundred and seven (0.87%) donors had a vasovagal reaction during or after blood donation. Donors who gave blood occasionally had a significant greater incidence of reactions compared with volunteer donors (1.15 versus 0.53%) (P < 0.001). There was no significant difference between men and women (0.85 versus 0.95%). First-time donors (1.7 versus 0.68%) and those under 30 years (1.15 versus 0.71%] had a significant greater possibility to have a reaction (P < 0.001). Twenty-two of 107 (20.5%) donors had a syncopal reaction. There was not a causative correlation of haematocrit, haemoglobin, systolic and diastolic blood pressure, pulse rate and weight in women (except weight in men) in developing a reaction. The stressing experience of phlebotomy was the reason for the higher frequency of a reaction. The incidence of reactions in our donors is lower than in other studies, and the possible reason for this is that only physicians are responsible for the selection of donors and trained personnel are careful of them during the donation process.     

Age-related donor return patterns among first-time blood donors in the United States

BACKGROUND: Committed repeat donors are vital to the continued success of blood collections, yet the effect of age of first-time (FT) donation on return behavior is poorly described. Sixteen-year-old donors are increasingly allowed to donate and have the highest rates of adverse events, which negatively impacts return behavior.
STUDY DESIGN AND METHODS: Annual cohorts of allogeneic FT donors from 2005 and 2006 were selected within the American Red Cross system and followed for 25 and 13 months, respectively. Return and total yield rates among different age groups were compared.
RESULTS: A total of 2.3 million FT donors from 2005 and 2006 gave 4.2 million donations during the study. Sixteen- to 19-year old FT donors made up 41% of the FT donor base in 2005 and 16-, 17-, 18-, and 19-year-olds, respectively, had initial return rates of 62, 52, 35, and 28% and yield rates of 2.0, 1.76, 1.51, and 1.41 over 13 months. Multivariate analysis of FT yield rates shows that younger (16 and 17 years) and older (50+ years) donors, males, blood group O donors, and those without any initial adverse reaction are most likely to return. Increasing severity of donor adverse reactions correlated with a reduction in yield and return rates.
CONCLUSION: FT 16-year-old donors had the highest return and yield rates despite the negative impact of increased adverse event rates. Donation at young age is critical to building a cadre of committed repeat donors but donor reactions must be addressed to ensure the donors' well-being and to sustain return behavior.     

Establishment of an immunoglobulin A-deficient blood donor registry with a simple in-house screening enzyme-linked immunosorbent assay

BACKGROUND: Transfusion of blood products to immunoglobulin A (IgA)-deficient patients who have developed IgA antibodies can result in serious adverse reactions. To prepare compatible blood components for these patients, blood centers usually maintain a list of IgA-deficient blood donors. An in-house enzyme-linked immunosorbent assay (ELISA) was used to identify new IgA-deficient blood donors. STUDY DESIGN AND METHODS: An in-house ELISA was used to screen blood samples. IgA-deficient samples, defined as an IgA level below 0.05 mg per dL, were sent to the American Red Cross for confirmatory testing. RESULTS: Seventy-three confirmed IgA-deficient blood donors were identified among 38,759 screened blood donor samples (frequency, 1:531). IgA antibodies were found in 39 of these 73 blood donors (53%), although only 9 donors had a history of adult IgA exposure (transfusion or pregnancy). CONCLUSIONS: With a simple in-house ELISA, 73 blood donors were identified as IgA-deficient. From this number, 34 donors, without detectable anti-IgA in their plasma, were added to our IgA-deficient blood donor panel to maximize the management of our inventory of IgA-deficient frozen blood components.     

Donation reactions among autologous donors

Studies of risk factors associated with reactions among autologous blood donors have been limited. Therefore, 2091 autologous and 4737 homologous donations were examined. Donors at greatest risk for reaction were autologous donors who had reactions at first donation; among 45 who made repeat donations for the same surgery, 17 (38%) had repeat reactions. The group least likely to experience reactions were the autologous donors greater than or equal to 66 years old; they experienced a 1.9 greater than or equal to percent (6/310) incidence of reactions. More reactions were seen in both autologous and homologous donors in the categories of first-time donor, female gender, decreasing age, and lower weight. Multiple logistic regression analysis showed that all of these variables were independent predictors of donor reaction, with first-time donation (odds ratio, 2.4) and female gender (odds ratio, 1.9) being the strongest predictors of reaction. Donor room personnel should be alerted that autologous donors who react at first donation are very likely to react at subsequent donations. Contrary to common concern, elderly autologous donors are least likely to have reactions.     

A study of 178 consecutive vasovagal syncopal reactions from the perspective of safety

BACKGROUND: While vasovagal syncopal reactions have been studied in the past, there are several safety questions that could be further addressed. The purpose of this study was to address these safety questions. STUDY DESIGN AND METHODS: One hundred seventy-eight vasovagal reactions were reported in 1999 from 194,000 blood donations. The reactions were retrospectively reviewed for 38 variables that included donor demographics, symptoms, injury, and final disposition. RESULTS: Sixty-one percent of the syncopal reactions occurred at the refreshment table and 12 percent offsite. Fourteen percent of the donors sustained an injury, usually to the head (10%). Eleven donors (6%) had additional medical care in an emergency room: 4 for injuries, 3 for delayed recovery, and 4 for offsite syncope. None of the donors was admitted to the hospital. One of the injured donors developed postconcussion syndrome and had later sequelae. CONCLUSION: Syncopal reactions most commonly occur at the refreshment table, where preventive safety measures against trauma could be applied. A significant number of syncopal reactions occur offsite, where the environment is less safe. The injuries that occur, particularly to the head, may in rare cases lead to long-term sequelae.     

Water administration and the risk of syncope and presyncope during blood donation: a randomized clinical trial

BACKGROUND: Blood centers rely heavily on adolescent donors to meet blood demand, but presyncope and syncope are more frequent in younger donors. Studies have suggested administration of water before donation may reduce syncope and/or presyncope in this group. STUDY DESIGN AND METHODS: We conducted a randomized, controlled trial to establish the effect of preloading with 500 mL of water on the rate of syncope and presyncope in adolescent donors. School collection sites in Eastern Cape Province of South Africa were randomized to receive water or not. Incidence of syncope and presyncope was compared between randomization groups using multivariable logistic regression. RESULTS: Of 2464 study participants, 1337 received water and 1127 did not; groups differed slightly by sex and race. Syncope or presyncope was seen in 23 (1.7%) of the treatment and 18 (1.6%) of the control arm subjects. After adjusting for race, sex, age, and donation history, there was no difference in outcome between the water versus no water arms (adjusted odds ratio [OR], 0.80; 95% confidence interval [CI], 0.42‐1.53). Black donors had sevenfold lower odds of syncope or presyncope than their white counterparts (adjusted OR, 0.14; 95% CI, 0.04‐0.47). CONCLUSION: Preloading adolescent donors with 500 mL of water did not have a major effect in reducing syncope and presyncope in South African adolescent donors. Our adolescent donors had lower overall syncope and presyncope rates than similar populations in the United States, limiting the statistical power of the study. We confirmed much lower rates of syncope and presyncope among young black donors.     

Assessment of donor fear enhances prediction of presyncopal symptoms among volunteer blood donors

BACKGROUND: Fear is an important contributor to the risk of presyncopal reactions to blood donation. However, concern that asking donors about their fears may increase the risk of reactions is a potential impediment to incorporating fear assessment into donor screening. STUDY DESIGN AND METHODS: Before donation, participants responded to a series of questions that either did (n = 488) or did not (n = 494) include questions related to fear of seeing blood drawn. Immediately after donation all participants provided ratings of presyncopal reactions. RESULTS: Among those asked predonation fear questions, fear was most strongly related to presyncopal symptoms when compared against other donor characteristics (e.g., age, number of prior donations, body mass index, estimated blood volume, blood pressure, and pulse). However, Mann‐Whitney U tests revealed that being asked about fear before donation was not associated with higher reports of presyncopal reactions for the sample as a whole, nor among novice donors. Further, regression analyses indicated that fear remained a significant predictor of presyncopal reactions in final models that included age and number of prior donations as significant predictors. CONCLUSION: Predonation assessment of fear of blood draws may help to identify donors who are most likely to benefit from brief interventions designed to enhance donor coping, reduce risk of presyncopal reactions, and increase donor retention.     

Donor reactions in high-school donors: the effects of sex, weight, and collection volume

BACKGROUND: The high incidence of donor reactions in first-time, 17-year-old Caucasian whole-blood donors makes this group ideal for the study of donor reactions. STUDY DESIGN and METHODS: Donor reaction rates were retrospectively evaluated in 7274 first-time, 17-year-old Caucasian whole-blood donors based on observations recorded at the collection sites. The effect of sex and weight on donor reactions was determined. In addition, a model was developed to estimate how different blood collection volumes would affect donor reaction rates. RESULTS: The donor reaction rate was 12.0 percent (870/7274). Female donors overall had a higher donor reaction rate than male donors (16.7% vs. 7.3%) and also had a higher donor reaction rate than male donors at each 20-lb weight interval in the range from 110 to 189 lb. A model suggested that a change in the blood-unit volume from 450 to 500 mL would increase donor reaction rates by 18 percent in either female or male donors, whereas a reduction in the blood-unit volume from 500 to 400 mL would decrease donor reaction rates by 29 and 27 percent in female and male donors, respectively. CONCLUSION: First-time, 17-year-old Caucasian female donors had a higher donor reaction rate than male donors overall and at equivalent donor weights. In the range of present US blood-unit volumes, a change in collection of as little as 50 mL could have a significant impact on blood donor reaction rates in high-school students.     

四川遂宁地区献血者G-6-PD调查及进食蚕豆对蚕豆病儿输血的影响

应用改良四唑氮兰法对2483名献血者进行红细胞G-6-PD调查,G-6-PD缺乏率为8.3％,其中显著缺乏率为2.1％。建立献血者G-6-PD调查档案,防止蚕豆病儿输入缺乏G-6-PD的血液,提高了输血安全。观察献血者进食蚕豆后不同时间(2～4小时,12～24小时,2～3天)采血对蚕豆病儿输血的影响,各观察组临床症状与外周血Hb的恢复、G-6-PD活性的改变和对照组比较无明显差别,各组均未发现再溶血病例。提示蚕豆病儿在急性溶血后“不应期”内输入进食了蚕豆的献血者的血液无明显不良影响。     

Physiologic strategies to prevent fainting responses during or after whole blood donation

Vasovagal syncope (VVS) is a consistent, but infrequent (0.1%-0.3%) complication of volunteer, whole blood donation. Given the large number of blood donations, a significant number of donors is involved. Syncope occasionally leads to injury. Recent rigorous data collection and analysis have led to the association of a small number of donor and donation factors with the risk of syncope. An analysis of the time course of syncope reactions among approximately 500,000 whole blood donors suggests that there are three distinct periods of risk for vasovagal reactions before, during, and after phlebotomy. This review examines the physiologic mechanisms that contribute to these periods of increased risk including the direct effects of removal of approximately 500 mL of whole blood, the psychological stress of instrumentation and giving blood (i.e., fear of needles, pain, and the sight of blood), and the orthostatic effects superimposed on a hypovolemic state after the donation. Specifically, we describe interventions that have been useful in controlling VVS in patients with fainting syndromes and we examine the potential of these interventions in the blood donation context, based on the physiologic principles involved. Finally, we propose an intervention (dietary replacement of salt lost with blood donation) that has not been applied in transfusion medicine previously but which has the potential to reduce risk.     

Vasovagal reactions in whole blood donors at three REDS-II blood centers in Brazil

BACKGROUND: In Brazil little is known about adverse reactions during donation and the donor characteristics that may be associated with such events. Donors are offered snacks and fluids before donating and are required to consume a light meal after donation. For these reasons the frequency of reactions may be different than those observed in other countries. STUDY DESIGN AND METHODS: A cross‐sectional study was conducted of eligible whole blood donors at three large blood centers located in Brazil between July 2007 and December 2009. Vasovagal reactions (VVRs) along with donor demographic and biometric data were collected. Reactions were defined as any presyncopal or syncopal event during the donation process. Multivariable logistic regression was performed to identify predictors of VVRs. RESULTS: Of 724,861 donor presentations, 16,129 (2.2%) VVRs were recorded. Rates varied substantially between the three centers: 53, 290, and 381 per 10,000 donations in Recife, São Paulo, and Belo Horizonte, respectively. Although the reaction rates varied, the donor characteristics associated with VVRs were similar (younger age [18‐29 years], replacement donors, first‐time donors, low estimated blood volume [EBV]). In multivariable analysis controlling for differences between the donor populations in each city younger age, first‐time donor status, and lower EBV were the factors most associated with reactions. CONCLUSION: Factors associated with VVRs in other locations are also evident in Brazil. The difference in VVR rates between the three centers might be due to different procedures for identifying and reporting the reactions. Potential interventions to reduce the risk of reactions in Brazil should be considered.     

The effect of whole-blood donor adverse events on blood donor return rates

BACKGROUND: Some blood donation-related adverse events (AEs) can negatively impact the blood donor return rate (BDRR) and decrease donor retention. STUDY DESIGN AND METHODS: One-thousand randomly selected whole-blood donors were interviewed 3 weeks after a 525-mL index whole-blood donation for seven AEs. The number of return visits and duration of follow-up were recorded for each of the 1000 donors. A negative binomial regression analysis was used to determine the contribution of the four most common AEs to the BDRR, and interactions between these AEs were also evaluated. RESULTS: The four most common AEs were bruise alone (15.1%), sore arm "alone" (7.0%), fatigue "alone" (5.1%), and donor reaction "alone" (4.2%), where "alone" is defined to also include donors who had a bruise but no other AE. The estimated BDRR for donations without AEs was 1.32 visits per year. The estimated BDRRs for the four most common AEs were: bruise alone, 1.32 visits per year; sore arm alone, 1.30 visits per year (2% reduction in BDRR); fatigue alone, 1.06 visits per year (20% reduction in BDRR); and donor reaction alone, 0.87 visits per year (34% reduction in BDRR). The BDRR for donor reaction, fatigue, and sore arm together was 0.20 visits per year (85% reduction in BDRR). CONCLUSION: Donor reaction had the most negative impact on the BDRR. There appears to be a synergistic effect between donor reaction, fatigue, and sore arm. Theoretically, amelioration of some AEs has the potential to improve BDRRs.     

Adverse reactions, psychological factors, and their effect on donor retention in men and women

BACKGROUND: This study investigates the effect of a vasovagal reaction (VVR) or needle reaction (NR) on the risk of stopping as a blood donor, taking into account variables from the Theory of Planned Behavior (TPB). Is stopping risk solely related to the adverse reaction itself, or do the TPB variables play a role as well? Emphasis is placed on possible sex differences. STUDY DESIGN AND METHODS: TPB variables were assessed within 12,051 whole blood donors. Also, donors reported the occurrence of adverse reactions during or after their last donation. Blood bank records were used to determine whether donors stopped donating within the next 2 years. Logistic regression analyses were performed to estimate the effect of self‐reported adverse reactions on stopping risk, adjusting for the TPB variables. Analyses were performed separately for both sexes. RESULTS: Men have a lower odds of reporting a NR or a VVR than women (odds ratio [OR] 0.34, 95% confidence interval [CI], 0.28‐0.43; and OR 0.26, 95% CI 0.19‐0.36, for NR and VVR, respectively). For both sexes, only a VVR was associated with stopping risk, which is higher in men (men, OR 3.95, 95% CI 2.19‐7.11; women, OR 1.78, 95% CI 1.35‐2.35). After adjusting for the TPB variables both ORs declined (men, OR 3.38, 95% CI 1.86‐6.15; women, OR 1.58, 95% CI 1.17‐2.14). Also, self‐efficacy and affective attitude are negatively associated with adverse reactions. CONCLUSION: Female donors report more VVRs than male donors, but male donors have a higher stopping risk after a VVR than female donors. Coping differences and possible reporting tendencies might play a role. For donor retention purposes, prevention and coping techniques should take sex differences into account.