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

Abstract

Background Blood centers rely heavily upon adolescent donors to meet blood demand, but pre-syncope and syncope are more frequent in younger donors. Studies have suggested administration of water prior to donation may reduce syncope and/or pre-syncope in this group. Study design and methods We conducted a randomized, controlled trial to establish the effect of pre-loading with 500ml of water on the rate of syncope and pre-syncope in adolescent donors. School collection sites in Eastern Cape Province of South Africa were randomized to receive water or not. Incidence of syncope and pre-syncope was compared between randomization groups using multivariable logistic regression. Results Of 2,464 study participants, 1,337 received water and 1,127 did not; groups differed slightly by gender and race. Syncope or pre-syncope was seen in 23 (1.7%) of the treatment and 18 (1.6%) of the control arm subjects. After adjusting for race, gender, age and donation history, there was no difference in outcome between the water versus no water arms (adjusted odds ratio (OR) = 0.80 (95% CI 0.42–1.53). Black donors had 7-fold lower odds of syncope or pre-syncope than their white counterparts (adjusted OR 0.14, 95% CI 0.04–0.47). Conclusion Preloading adolescent donors with 500ml of water did not have a major effect in reducing syncope and pre-syncope in South African adolescent donors. Our adolescent donors had a lower overall syncope and pre-syncope rate than similar populations in the USA, limiting the statistical power of the study. We confirmed much lower rates of syncope and pre-syncope among young Black donors.

Prevention of syncopal‐type reactions after whole blood donation: a cluster‐randomized trial assessing hydration and muscle tension exercise

“…To our knowledge, this is the first large randomized study to assess the effect of an isotonic drink consumed just before phlebotomy in preventing syncopal‐type reactions in whole blood donors, compared with other previously described preventive interventions (i.e., drinking water and muscle tensing exercise) . The cluster randomization method avoided the bias of subjective perception of adverse reactions in donors as all the donors present in a donation unit on the same day were asked to do the same things.…”

A randomized trial to evaluate the use of text messaging, letter, and telephone call reminders to improve return of blood donors with reactive serologic tests

“…The design of the trial, study procedures development, and implementation were straightforward and can be applied to answer other research questions in blood banking beyond recruitment and recall of donors. For example, evaluating interventions to prevent donor reactions, such as providing water before donation to prevent reactions 10,11 as well as the use of transfusion of prophylactic components.…”

Management of Young Blood Donors

“…A recent editorial stated that compliance should be improved for these two measures [71]. A recent South African study had a compliance rate of 81% for young donors drinking all of the water where 75% were repeat donors [72]. In the study by Newman et al [51], the donor refusal rate was 1.4%.…”