Shih, Andrew W.

Abstract Background Cryoprecipitated antihemophiliac factor (cryo) is primarily used to replenish fibrinogen in acquired coagulopathy. Little has been reported about its usage patterns within hospitals with respect to patient population, frequency of use, and dosing. Study design and methods Cryo production and usage data were collected over 5 years from July 1, 2016, to June 30, 2021, from nationally based blood collection centers in the United States (U.S. n = 2) and Canada ( n = 2) and from eight large academic hospitals, respectively. Usage data for a similar product, purified fibrinogen concentrate were also collected from four hospitals. Results Two U.S. blood collectors reported increases in cryo production normalized to total whole blood collections from 17.4% in 2016 to 22.3% in 2021 and from 16.4% in 2016 to 20.2% in 2021. In contrast, in Canada cryo manufacturing increased slightly in one region (11.3%–12.9%) and decreased (8.0%–2.0%) in the other. Cryo utilization, defined as numbers of patients treated normalized to the inpatient census, and dose administered per patient did not consistently increase and differed significantly between hospitals participating in the study ( p < .0001). Likewise, the departments that most frequently transfused cryo varied between hospitals. Similarly, variations in practice were observed for fibrinogen concentrate usage. Conclusion While much of Canada and Europe have moved towards using fibrinogen concentrate, two large U.S. collectors have increased cryo distribution. The lack of standardization and variability in the clinical practice regarding the use of cryo and fibrinogen concentrate reported by study sites may be attributable to practitioner preference, availability, and/or cost rather than adherence to published evidence or guidelines.

AbstractPrior studies have suggested that immune thrombotic thrombocytopenic purpura (iTTP) may display seasonal variation; however, methodologic limitations and sample sizes have diminished the ability to perform a rigorous assessment. This 5‐year retrospective study assessed the epidemiology of iTTP and determined whether it displays a seasonal pattern. Patients with both initial and relapsed iTTP (defined as a disintegrin and metalloprotease with thrombospondin type motifs 13 activity <10%) from 24 tertiary centers in Australia, Canada, France, Greece, Italy, Spain, and the US were included. Seasons were defined as: Northern Hemisphere—winter (December–February); spring (March–May); summer (June–August); autumn (September–November) and Southern Hemisphere—winter (June–August); spring (September–November); summer (December–February); autumn (March–May). Additional outcomes included the mean temperature in months with and without an iTTP episode at each site. A total of 583 patients experienced 719 iTTP episodes. The observed proportion of iTTP episodes during the winter was significantly greater than expected if equally distributed across seasons (28.5%, 205/719, 25.3%–31.9%; p = .03). Distance from the equator and mean temperature deviation both positively correlated with the proportion of iTTP episodes during winter. Acute iTTP episodes were associated with the winter season and colder temperatures, with a second peak during summer. Occurrence during winter was most pronounced at sites further from the equator and/or with greater annual temperature deviations. Understanding the etiologies underlying seasonal patterns of disease may assist in discovery and development of future preventative therapies and inform models for resource utilization.