Blood collected from blood donors is routinely divided into its different components, red blood cells, plasma and platelets. These components are stored under different storage conditions and their maximum storage time before transfusion is different. Platelets are stored at a maximum of 7 days and at a temperature of 22°C to best preserve their function.

Research has been conduction on blood stored and transfused as whole blood (without separation into the various components), particularly in situations of acute trauma. Region Örebro län will therefore start transfusion of whole blood in such situations. The whole blood units will be stored at 4°C for a maximum of 14 days. This means that the platelets will be stored at a lower temperature than standard and for a longer time period. The research on how this will affect platelet function is limited.

This project aims to determine how the patients are affected regarding coagulation, hemolysis, renal function, immunisation, transfusion reactions and the effect of substances released from the blood cells in the whole blood units during the storage period and if there is an impact on mortality.

Blood collected from blood donors is routinely divided into its different components, red blood cells, plasma and platelets. These components are stored under different storage conditions and their maximum storage time before transfusion is different. Platelets are stored at a maximum of 7 days and at a temperature of 22°C to best preserve their function.

Platelets function is to contribute to the formation of a clot to stop and prevent bleeding. Previous studies has shown that this might be affected if they are stored refrigerated. Exactly how they are affected is not known and when this occurs during the storage period.

Research has been conduction on blood stored and transfused as whole blood (without separation into the various components), particularly in situations of acute trauma. Region Örebro län will therefore start transfusion of whole blood in such situations. The whole blood units will be stored at 4°C for a maximum of 14 days. This means that the platelets will be stored at a lower temperature than standard and for a longer time period. The research on how this will affect platelet function is limited.

Since transfusion of refrigerated whole blood is a new procedure this project aims to determine how the patients are affected regarding coagulation, hemolysis, renal function, immunisation, transfusion reactions and the effect of substances released from the blood cells in the whole blood units during the storage period and if there is an impact on mortality.

Patients requiring transfusion with a whole blood due to an acute situation with bleeding will be enrolled. Blood samples will be taken from the patients for analysis directly before the transfusion and at various time points after the transfusion. Clinical variables of importance to interpret the effect of the whole blood transfusion will be registered as well as basic information such as sex, age, height, weight, blood group and type of injury causing the bleeding, treatment etc.

Inclusion Criteria:

• Patient with acute bleeding
• Transfused with whole blood at the time of the acute bleeding episode

Exclusion Criteria:

• Patients where vital information lacking needed to interpret data (i.e. blood cell count)

Patient with acute bleeding that are transfused with whole blood at the time of the acute bleeding episode.