Transfusion Error Surveillance System (TESS)

Pilot Project Report 2005–2007

Executive Summary

Blood transfusion is a critical component of healthcare and errors in the transfusion chain can result in ABO incompatibilities, administrative delays, product wastage, inappropriate transfusions, and the possible need for sample re-collection. These errors have a potential to impact on patient safety.

The surveillance of errors in the pre- and post- administration of blood in the transfusion chain can be considered the foundation of process improvement and corrective actions within the blood transfusion system. In response to the Krever commission recommendations for blood safety, the Public Health Agency of Canada (PHAC) conducts ongoing surveillance for transfusion-related errors in collaboration with the Ministries of Health in provinces and territories and Canadian hospitals.  In 2005, the Transfusion Error Surveillance System (TESS) pilot project was developed with a goal to assist hospitals in evaluating and improving their blood transfusion procedures, and ultimately, increasing patient safety.

TESS was implemented in 11 hospitals in 4 Canadian provinces to monitor the frequency of a pre-defined set of errors that occur in the transfusion chain. All data were captured anonymously. Denominator data were collected based on: blood components and blood products received, requested, prepared, and issued as well as samples received and tests performed. Data were entered by hospitals on a web-based secure server.

Between January 2005 and December 2007, there were 1,492,673 tests conducted on blood samples taken and 614,543 units of blood transfused at participating sites, with 31,989 errors reported. All errors were broken down into classifications of Administration and Potential Severity. Administration errors were subdivided into pre-administration (caught before a blood product was administered to the patient) and post-administration (after the patient received a transfusion). All errors were examined for Potential Severity (measure used to determine outcome if the error went undetected).

For the classification based on Administration, the vast majority of errors, 31,047 (97%), were detected and remedied before any transfusion occurred (pre-administration) and involved a single error.  There were 942 (3%) errors reported where the patient received a transfusion (detected only after post administration).  Of these errors, only 23 resulted in an adverse event, which included minor allergic reactions or fever.  This number correlates to 23 adverse events out of 614,543 units of blood transfused - an adverse events rate of 4 per 100,000 transfusions. No severe reactions, such as anaphylaxis, were reported. No deaths were reported.

For the classification based on Potential Severity (measure used to determine outcome if the errors went undetected), the majority of errors, 26,430 (82.6%) were classified as low severity, while 2,587 (8.1%) were medium and 2,969 (9.3%) were of high severity. With respect to the errors classified as high severity, the 23 errors noted above are captured within the 2969.

Findings indicate that the most common points in the ‘transfusion chain’ for errors to occur were at sample collection and unit transfusion. Front line personnel such as nurses, blood bank technologists, and physicians were the personnel most frequently involved in errors, accounting for 46.6%, 39.7%, and 6.5% respectively. The most common type of error was sample collection error; with an error rate of 1 in 48 samples collected. Sample collection error rates were highest in the emergency departments, operating rooms and intensive care units (in locations with high levels of acuity).  It is important to note that approximately three quarters of these errors (73.7%) were detected before the blood product was ever issued, and within 48 hours of the error occurrence.

Of the 2,969 high-severity errors, 86.6% occurred in the clinical area and fell into five general categories: sample collection (51.0%), sample handling (11.6%), product/test request (10.3%), request for pick-up (4.9%), and unit transfusion (4.8%). High-severity errors were somewhat more common in smaller institutions, but the difference did not reach statistical significance.

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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