2. English summary

Adverse events in the transfusion service that did not lead to clinical reactions in blood donors or in patient, but that in other circumstances could have lead to serious effects, are called unwanted adverse events. This report presents all such events reported to the Norwegian Haemovigilance system in 2021.

Melde.no, a digital portal for multiple reporting systems in the country, was implemented in 2021. The implementation was successful despite a few reporting mistakes. Some of our classifications have now been harmonised to the Norwegian coding system for unwanted adverse patient events, and several classification categories have been substituted by others. The "Human error" category for example has been removed, and the reports are now subclassified depending on whether the error occurred due to deviation from the procedures, suboptimal communication, equipment failure, failure in information and communication technology, suboptimal organization or other contributing factors.

The Hemovigilance system in Norway received 137 reports classified as unwanted adverse events in 2021. Of these, 59 (43%) were reports of newly discovered anti-D in women.

The remaining 78 reports were distributed as follows:

The remaining 20 reports were classified under other main process categories and are described later in this report.

35 (45%) reports determine that "Procedure" is the primary cause for the unwanted event, however as many as 64 (54%) of the reports, have this causal category as one of the causes. Previously, these reports would have been classified as "Human error". Most of the reports classified as "Blood sample taken from the wrong person", "Blood sample not labelled correctly", "User error" and “Failure in ccommunication" would be classified as human error. Totally, there are 50 (64%) reports where the primary cause can be classified as "Human error".

7 (9%) reports classified as "Known complication/calculated risk" and 9 (12%) are classified as "Other contributing cause". These would have been classified as "No error" in the old system. Approximately half of these reports are in the main process category "Blood donor selection", where the donor has filled out the questionnaire and been interviewed but still have neglected to provide important information.

The primary contributing factor is stated to be “Failure in information and communication technology/Failure in equipment” in 3 reports (4%), “Deficient procedure” in 2 (3%) and “Organisation failure” (training, competence, and resources) in 6 reports (8%). 95% of these reports are classified as certainly or probably preventable.

In 2021, we received 14 (18%) reports of incorrect blood transfused without serious clinical effects. It's about the same number as for previous years. In 2 of the cases blood was compatible but given to the wrong patient, in 4 cases the blood was ABO incompatible. In 2 of these cases the product transfused was plasma while the other 2 were red blood cells concentrates. All of these 6 cases could potentially lead to serious consequences. In 2 of the cases there was a deviation of the procedure for transfusion of stem cell transplanted patient, and in 1 case to old blood was transfused to a child under the age of 1. 11 (78%) of these reports were classified as “Certainly preventable”. The remaining 3 cases were classified as “Not preventable”. In these cases, an emergency blood transfusion with O RhD negative blood was indicated before the results of screening for red blood cell alloantibodies where completed. The screenings revealed alloantibodies that in some of the cases made the blood bags incompatible. It is good that one realizes the possibility for improvement after such event and implement counter measures to avoid repetition.

This report contains 21 examples of adverse events. These examples describe events that could occur in other parts of the transfusion service as well.  By looking at what other hospitals have reported, we can assess whether the same can happen at our own hospital or blood bank and make  precautions. Learning in this way is one of the goals for the Haemovigilance system.