Faint and prefaint reactions in whole-blood donors: an analysis of predonation measurements and their predictive value.

BACKGROUND: A small proportion of blood donors have adverse reactions. The purpose of this study was to determine predictors of faint and significant hypotensive reactions that could serve as targets for interventions to reduce reactions, thus improving the blood donation experience for those at higher risk of reactions and reducing the risk of serious adverse events. STUDY DESIGN AND METHODS: The records of 422,231 allogeneic whole-blood donations from a 9-month period were assessed for adverse reactions. Incidents related to needle insertion, such as hematoma, were excluded. Demographic, biometric, and clinical measurements were collected. Reactions were analyzed by multivariate logistic regression analysis comparing donors with any adverse reaction to donors without reactions and by stratified rates according to reaction severity. RESULTS: The overall reaction prevalence was 1.43 percent. Of the reactions, 63, 29, and 8 percent were classified as mild, moderate, and severe, respectively. Markers of reactions were age, sex, race, blood volume, blood pressure, pulse, and body mass index. Compared to donors without reactions, the strongest predictor of a reaction was a donor's blood volume of less than 3500 mL (odds ratio [OR], 2.9; 95% confidence interval [CI], 2.57-3.23). Age and first-time status were also associated with a significantly higher risk of reaction with 17- to 18-year-olds (OR, 2.8; 95% CI, 2.59-2.98) and 19- to 24-year-olds (OR, 2.39; 95% CI, 2.23-2.56) at higher risk compared to 25- to 65-year-olds and first-time donors at higher risk compared to repeat donors (OR, 2.2; 95% CI, 2.07-2.33). CONCLUSION: The results of this study are helpful in identifying donors at risk for adverse reactions and in understanding the contributors to reactions. Donor blood volume was an unexpectedly strong predictor of reaction. Potential interventions to reduce the frequency of reaction are discussed.

The safety profile of automated collections: an analysis of more than 1 million collections.

BACKGROUND: Recent technology allows for the collection of 2-unit red cells (RBCs) and single-unit RBCs plus plasma or platelets (PLTs). STUDY DESIGN AND METHODS: With a common definition of adverse events, 1,023,682 whole-blood collections were evaluated and compared with 249,154 two-unit apheresis RBC collections, 40,870 single-apheresis RBC collections, and 90,082 apheresis PLT collections. RESULTS: The data show that manual whole-blood collections have a low incidence of moderate and severe reactions (47.1 per 10,000 collections, 0.47%). Single-unit RBCs collected by apheresis have the same safety profile (37.44 per 10,000 collections, p > 0.20). Double-RBC collections by apheresis and plateletpheresis have a significantly lower reaction rate (15.65 per 10,000 collections, p < 0.00005; and 14.84 per 10,000 collections, p < 0.00005, respectively). CONCLUSION: It is concluded that automated collections are safe or safer than manual whole-blood collections. There should be few concerns when procedures are performed according to manufacturer's instructions.

Two-year experience with aerobic culturing of apheresis and whole blood-derived platelets.

BACKGROUND: Throughout its system of regional centers, Blood Systems implemented culture based bacterial testing with a standardized protocol for both apheresis and whole blood-derived platelets (PLTs). STUDY DESIGN AND METHODS: After a 24-hour hold, 4 mL of PLT product was inoculated into an aerobic bottle (BacT/ALERT, bioMérieux). Cultures were incubated for 24 hours before routine product release to prevent distribution of infected products while minimizing consignee notification, product retrievals, and hospital PLT inventory problems. Initial-positives were further tested (and bacteria identified) by performing cultures from the original component and subcultures from the BacT/ALERT bottle. Results were categorized according to AABB recommended definitions with minor modifications. RESULTS: The rate of true-positive detections from culturing 122,971 apheresis PLTs was 0.017 percent (95% confidence interval [CI], 0.011%-0.026%). All true-positive microorganisms were Gram-positive with a predominance of coagulase-negative Staphylococcus and Bacillus species. Twenty of the 21 true-positive samples (95%) were detected by 24 hours but only 14 (68%) were detected by 18 hours. The false-positive rate due to contamination was 0.1 percent with the majority of isolates being skin or environmental organisms. Results did not differ significantly for whole blood-derived versus apheresis PLTs. CONCLUSION: These data corroborate the fact that the rate of detection of truly contaminated PLT apheresis products in the United States is approximately 1 in 5000 (0.02%); this is lower than the 0.03 to 0.05 percent rates that were generally quoted in the literature before the implementation of prospective bacterial culturing programs.