P‐BB‐39 | Frequency of Vasovagal Reactions with Large‐Volume Plasma Donations in Canada
Bibliographic record
Abstract
Vasovagal reactions (VVR) are reported as one of the most common adverse events with blood donation, and there is concern of increased VVR with large volume plasma collection. There is limited research from blood operators regarding the optimal combination of VVR mitigation strategies. Here we describe the observed rate of VVR at our new plasma collection sites between 2020 and 2022. Plasmapheresis donors can donate weekly with the maximum volume per donation decided based on the total estimated blood volume (TEBV) which is calculated based on measured height and weight. There is a stepwise process for increasing plasma volume collected, starting at 13% TEBV and progressing to a maximum of 18% TEBV. At every subsequent donation, donors were asked about experiencing vasovagal reactions prior to progressing to a higher TEBV threshold. Donors with over 562 mL of plasma volume collected were also given a 500 mL saline infusion. All donors are also advised to eat pre-donation, participate in directed applied muscle tension during procedure and consume at least 500 mL of water and eat a salty snack post-procedure while resting. Data regarding gender at registration, volume progression, VVR rate and severity were analyzed between January 01 2020 to December 31 2022. Between 2020 and 2022, 19,185 donors made 78,401 donations. The average age of donors was 43 years. Of these, 36,961 (47.1%) of donations were made by donors registered as female. At the end of 2022, 18.5% of the donors registered as female and 24.3% of donors registered as male had completed the volume progression and were at 18% TEBV donation level. The overall frequency of VVR amongst donors registered as male was 14 in 10,000 donations, while those registered as female was 37 in 10,000 donations. Moderate to severe VVR occurred at 199 (0.25%) donations. Of these, 86 (43.2%) VVRs were severe. Amongst the donors with VVR, 136 were registered as female with 31 at their first donation. Of the 63 reactions in donors registered as male, 37 were at their first donation. Of the VVR reported, 170 (85.4%) occurred during donation. Saline was administered in 52906 (67.4%) of donations with VVR reported in 32 of these donations, and the odds of having a VVR with saline of 0.0923 (95% confidence interval 0.063 to 0.135; p < .0001). Within the first 2 years of large volume plasma collections at dedicated sites and current mitigation strategies, the VVR rate has been reported in 0.25% of donations with a reduced odds ratio during the procedures where saline infusions are given.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".