Transfusion Error Surveillance System (TESS)

Surveillance Report 2008-2011

Executive Summary

Blood transfusions are an important component of Canada’s health care system. Although Canada has one of the safest blood systems in the world, transfusion errors can occur at various points in the transfusion chain, which encompasses any point in the collection, labelling, testing, storing, handling, transfusion, etc. of blood and blood products. Transfusion-related errors may occur in either clinical or laboratory settings and may result in ABO incompatibilities, administrative delays, product wastage, inappropriate transfusions and the possible need for sample re-collection. Limiting opportunities for transfusion errors is therefore an important aspect of public health safety.

This report offers an analysis of the Transfusion Error Surveillance System (TESS) data reported from 2008 to 2011. Findings are presented for all transfusion-related errors, and for errors that were detected prior to blood transfusion as well as errors detected during and after blood transfusion.

The TESS was initiated in 2005 by the Public Health Agency of Canada (the Agency) to monitor errors occurring at any point in the transfusion chain. Currently, 15 hospitals participate in the surveillance and report all transfusion-related errors to the Agency on a quarterly basis. By tracking transfusion-related errors it is possible to identify not only the points in the transfusion chain where errors most commonly occur, but also the points where changes can be implemented in order to limit the opportunity for transfusion errors.

Between 2008 and 2011, a total of 34,088 transfusion-related errors were reported through the TESS and the frequency of transfusion-related errors remained relatively stable over this time frame. Of the 34,088 errors reported, 33,622 (98.6%) were detected prior to transfusion of the blood component to the patient and the remaining 466 (1.4%) were detected after blood transfusion.

Sample collection errors, which occurred at a rate of 1 error for every 46 samples received, accounted for the largest proportion (40.1%) of all errors reported through the TESS between 2008 and 2011. All these errors including errors related to haemolysis and labelling of samples which were the most common, were detected prior to blood transfusion and a large proportion originated from emergency rooms (39.7%) and medical/surgical wards (29.7%). Sample handling (10.4%), unit transfusion (8.8%), product request (7.8%), sample testing (7.3%) and sample receipt (6.2%) errors altogether accounted for 40.7% of all errors.

Transfusion errors originated primarily from transfusion services (22.5%), medical/surgical units (21.0%) and emergency rooms (20.7). Transfusion services also accounted for the detection of the vast majority (95.4%) of all transfusion errors, suggesting that a robust system of checks and balances has been put in place in these settings.

Overall, 82.9% of errors discovered prior to blood transfusion were detected on the same day of their occurrence and sample collection errors had the highest same-day detection rate of all error types detected before transfusion. In contrast, only 34.7% of errors detected after blood transfusion were discovered on the same-day of their occurrence and same-day detection rate varied substantially depending on the error type.

Of the errors detected after blood transfusion, 84.1% were identified as potential low severity, 1.7% as potential medium severity and 14.2% as potential high severity. Errors that are not detected until after blood transfusion and that are identified as potential high severity are of concern to patient safety, and so it is important to understand these types of errors. Of the 66 reported, 16 resulted in adverse effects such as transfusion-associated circulatory overload (n=8) and febrile non-hemolytic transfusion reaction (n=2). Other adverse transfusion effects noted were either mild (n=1) or of unspecified nature (n=5). Fifteen (93.8%) of the errors that led to adverse reactions originated from a hospital performing over 10,000 transfusions per year, and the remaining one that cause a mild transfusion reaction was from a hospital performing between 2,000 and 10,000 transfusions per year.

The TESS data from 2008 to 2011 demonstrate that blood transfusions are both safe and efficient in Canadian hospitals participating in the surveillance. Only 0.05% of all transfusion errors reported through the TESS resulted in patient harm and no cases of death were reported. While findings are undoubtedly suggestive of the effectiveness of error detection and remediation measures within participating hospitals, they also highlight potential areas for improvement. Most notably, sample collection errors accounted for a large proportion of all errors and therefore should be the target of quality improvement initiatives. Errors of potential high severity errors that may result in patient harm should be similarly targeted through corrective actions. Data collected through the TESS facilitate the identification and evaluation of preventive measures designed to optimize system efficiency and, most importantly, patient safety. For example, in a participating hospital, the TESS data have facilitated the adoption of prospective auditing of all blood requests to ensure compliance with hospital transfusion guidelines for both indication and dose. The surveillance of errors occurring at various steps throughout the transfusion chain therefore continues to represent an important aspect of patient safety in Canada.

To obtain an electronic copy of the report, send your request to:

Centre for Communicable Diseases and Infection Control
Public Health Agency of Canada
100 Eglantine Driveway
Tunney's Pasture
Ottawa, ON K1A 0K9

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