OA2-AM24-SN-15 - Frequency of Vasovagal Reactions with Large Volume Plasma Donations in Canada

Background/Case Studies: Historically, blood pressure (BP) measurements have been required to determine whether apheresis plasma donors can safely donate. Donors were accepted if systolic BP was between 90 to 180 mm Hg and diastolic BP was between 50 to 100 mm Hg. The utility of deferral for out-of-range BP to mitigate vasovagal reactions has not been well-studied in plasma donors.

Study

Design/Methods: A pragmatic observational study was conducted at one Plasma Donor Centre from August to December 2023. With donor consent, donor age, gender, weight, height, pre-donation BP, plasma collection volume and occurrence of vasovagal reactions (VVR) were recorded at each donation attempt. Donors proceeded with their donation regardless of their BP values. Currently, 500mL of saline is given to those donating over 550mL of plasma. The percentage of total blood volume (%TBV) was calculated for each donor. Data was analyzed using Proc Genmod of SAS program, descriptive statistics were obtained followed by an association analysis and a logistic regression model.

Results/Findings: A total of 4,040 donations occurred during the study period with 1,857 (46.0%) donations by female donors, 288 (7.13%) by first-time donors, a majority (64.0%) donating 12 – 15.9% TBV and 83.8% received saline infusions. Amongst 118 donors who had out of range pre-donation BP, 63 had low BP. None of the donors with out-of-range blood pressure reported experiencing a vasovagal reaction. There were 27 VVR reported and all of these donors had a BP value within the previously defined range. VVR were more common in first time donors (27.8 per 1,000 donations) compared to repeat donors (5.06 per 1,000 donations), among female (9.69 per 1,000 donations) compared to male (4.12 per 1,000 donations) donors and in those who did not receive saline. Younger age, first-time donor status, lower %TBV collected, lower TBV and absence of saline administration were associated with VVR occurrence (P < 0.01). The logistic regression model indicated that the odds ratio for not experiencing a VVR with saline administration vs without was 15.2.

Conclusions: Pre-donation BP measurement is not a reliable predictor of vasovagal adverse events in plasma donors. BP as a determinant of plasma donor eligibility may lead to unnecessary deferrals. To reduce the incidence of vasovagal reactions in plasma donors, other evidence-based mitigation strategies should be considered such as water, salty snacks, applied muscle tension and saline administration.