Severe influenza pandemic may lead to shortage of available RBCs

Research conducted in Germany using a mathematical model and computer simulations has found that a severe influenza pandemic could lead to a severe reduction in available red blood cell transfusion units.

Data from previous research has shown a correlation between a pandemic and the availability of red blood cells; however, detailed estimations have yet to be determined, according to researchers. In this study, they analyzed data from several major blood donation services to examine the management of blood supplies in Germany.

The researchers identified regular fluctuations of up to 10% in the numbers of supplied and transfused red bloods cells. They also found that non-urgent transfusions were, to some extent, synchronized with the overall availability of red blood cells, which allowed enough “elasticity” to cover the annual influenza season.

It was estimated that roughly ninety-five percent of daily released blood supplies were directly transfused whereas 5% expired due to mismatched blood type or logistics. A moderate pandemic scenario in this setting leads to a deficit of up to 110,000 transfusion units during about 10 weeks which allow for postponement if one assumes that only 70% of requested RBC are for urgent indications.

A deficit of up to 220,000 transfusion units during a simulated severe pandemic event, which could arise in five to six weeks, would result in a reduction of 40% to 50% in released units. If 70% of the requested transfusion units were for urgent indications in which postponement was not an option, up to 96,000 transfusion units would be denied, resulting in possibly fatal outcomes.

Other factors that could influence the number of available transfusion units include illness among blood services staff and a reduction in size of offered blood collection sessions to decrease spreading of influenza.

“A guideline on how to prioritize and postpone transfusions ready in the beginning of a pandemic can save critical resources for the pandemic peak,” the researchers said.

Kamp C. Transfusion. 2009;doi:10.1111/j.1537-2995.2009.02498.x.