(P-BC-68) Vasovagal Reactions in Apheresis Plasma Donors – “How was your first time?”

Background/Case Studies: Vasovagal reactions (VVRs) happen more often in first-time compared to repeat whole blood donations. The same is true also for apheresis donations. Blood centers usually recruit first-time apheresis donors among people who previously made at least one whole blood donation, with the goal of reducing their risk of VVRs. However, there is no published data that justifies this practice. Our center is now recruiting some apheresis donors with no previous experience with whole blood donation. We hypothesized that the rate of VVRs in first-time ever apheresis donors is comparable to the rate of VVRs in first-time whole blood donors, after considering other factors such as age, sex and estimated blood volume.

Study

Design/Methods: We measured VVRs (all levels of severity) among first-time whole blood and apheresis donors over a 12-month period (i.e., from December 2022 to December 2023). Logistic regressions were used to evaluate the association between the type of donation (i.e., whole blood vs. plasma) and VVRs. The analysis adjusted for sex, age and estimated total blood volume (ETBV). Odds ratios (OR) with corresponding 95% confidence intervals (CI) were calculated.

Results/Findings: The proportion of first-time ever apheresis donors having a VVR was 18.7% (95%CI = 17.20–20.25) and 13.4% (95% CI= 12.99–13.83) for first time ever whole blood donor. Among first-time ever donors, those who donated apheresis plasma had a higher rate of VVR than those who donated whole blood (OR [95% CI] = 1.56 [1.40–1.74]). This association was not explained by sex, age or ETBV. The risk of VVR in a first-time apheresis donor who previously made one or more whole blood donations was comparable to the risk in a first-time whole blood donor (OR [95% CI] = 0.974 [0.89–1.01]).

Conclusions: The risk of VVRs in first-time ever apheresis donors is significantly higher compared to the risk in those who made a previous whole blood donation or the risk in first-time whole blood donors. Knowing that VVRs have a negative impact on donor return rates, these findings could have significant implications for strategies aimed at attracting and retaining apheresis plasma donors. This issue is highly relevant in the current context where blood services strive to increase donations of plasma intended for fractionation.