Transfusion Error Surveillance System (TESS): 2008-2011 Summary Results

Acknowledgments: The development of the Transfusion Error Surveillance System (TESS) would not have been possible without the collaborative support and continued commitment of the many transfusion safety officers, medical laboratory technologists and other healthcare professionals in hospitals and blood transfusion services. Their dedication to reducing errors and increasing patient safety has led to the collection and analysis of the 2008-2011 the TESS data.

N.B. This document must be cited as the source for any information extracted and used from it.

Suggested citation: Public Health Agency of Canada. Transfusion Error Surveillance System (TESS) 2008-2011 Summary Results. Centre for Communicable Diseases and Infection Control, Public Health Agency of Canada, 2014.

Centre for Communicable Diseases and Infection Control
Public Health Agency of Canada
Tunney’s Pasture, AL 0602B
Ottawa, Ontario, K1A 0K9

E-mail: ccdic-clmti@phac-aspc.gc.ca

Information to the Reader of the Transfusion Error Surveillance System (TESS) 2008-2011 Summary Results

The Centre for Communicable Diseases and Infection Control (CCDIC) of the Public Health Agency of Canada (the Agency) is pleased to present the Transfusion Error Surveillance System (TESS) 2008-2011 Summary Results. These tabulated results present transfusion error surveillance data submitted by Canadian sentinel hospitals that participated in the Transfusion Error Surveillance System (TESS) from 2008 to 2011.

The TESS is a voluntary surveillance system established by the Agency to capture non-nominal data on errors occurring at any point in the transfusion chain, including those detected before or after transfusion of the blood product to the patient, as well as those that may or may not have resulted in adverse transfusion reactions. The overall goal of the TESS is to identify potential areas for improvement in the transfusion chain and, ultimately, improve patient safety in Canada.

CCDIC is responsible for the collection, management and analysis of the TESS data, as well as the production of reports summarizing key findings. CCDIC supports the use of these data to inform public health and policy action. In addition, CCDIC supports the Agency’s ongoing commitment to improving data quality, and to defining and setting surveillance standards.

Summary

The Transfusion Error Surveillance System (TESS) is a voluntary, anonymous, sentinel system that monitors the blood transfusion process for errors that involve patients who receive blood components or blood products (also known as plasma derivatives). Errors are defined as unexpected, unplanned deviations (attributable to human and the system/process) from standard operating procedures that could adversely affect the safety of patients or the quality of blood components or blood products. Initially launched as a pilot in 2005 with 11 hospitals from four Canadian provinces, the TESS moved to sentinel-type surveillance in 2008 with subsequent gradual recruitment of additional hospitals (one in 2008, two in 2009 and one more in 2010) to achieve a current total of 15 reporting hospitals. The sentinel hospitals participating in the TESS are responsible for about 9% of the transfusions of blood components and blood products performed in Canada each year.

From 2008 to 2011, 34,088 errors were reported to the TESS and of these, 33,622 (98.6%) were detected before and 466 (1.4%) after the blood component or blood product was transfused to the patient. Of the errors discovered before transfusion, no adverse outcomes were reported for 33,617 cases (99.99%) although there was a delay in the transfusion process for 1,036 (3.1%) of these cases. The remaining five cases (0.01%) were lost to follow up before any outcome could be determined.  The majority of the errors discovered before transfusion (72%, n=24,173) occurred in clinical settings (hospitals units/wards where patients can receive a transfusion) with the remaining (28%, n=9,449) occurring in laboratory settings (blood suppliers, supplier/service providers, laboratory, and transfusion services).  This distribution was very similar to that of the 466 errors identified after transfusion of the blood components or blood products with 74.9% occurring in clinical settings versus 25.1% occurring in the laboratory settings.

For the 466 errors discovered after the actual transfusion, which could have resulted in a patient developing an adverse reaction, the potential severity was assessed using an ordinal (low-medium-high) scale. Errors that had potential to cause serious injury or fatal outcome were assigned high potential severity, whereas those with potential to cause minor/transient injury were assigned medium potential severity. Low potential severity was assigned to errors with no potential for adverse effects.  Of the 466 errors discovered after the actual transfusion had occurred, 66 (14.2%) were classified as potential high severity, 8 (1.7%) classified as potential medium severity and the remaining 392 (84.1%) were deemed to be of potential low severity. For the 400 low and medium potential severity errors, 59 (14.8%) were lost to follow up and the remaining 341 (85.2%) had no negative impact on the patients.

For the 66 errors of potential high severity, 16 resulted in an adverse transfusion reaction; 44 (66.7%) had no negative impact to the patients at all and no outcome data were available for the remaining 6 (9.1%) errors. The 16 (24.2%) errors that were associated with a transfusion reaction had the following outcomes:  8 were classified as a transfusion-associated circulatory overload (TACO), 2 as febrile non-hemolytic reaction, 1 as a mild transfusion reaction, and 5 could not be specified though were definitely related to transfusion. Errors that resulted in TACO were linked to inappropriate/incorrect/ order of blood components or blood products (n=6) and not following guidelines for infusion time (n=2), whereas the cases of febrile non-hemolytic (n=2) and mild (n=1) transfusion reactions were linked to administration of product with an incompatible IV fluid, incorrect order of blood component/blood product and not following guidelines for infusion time, respectively.

In conclusion, of the total 34,088 errors reported during the 2008 to 2011 time period, there were only 16 errors (1.4%) that resulted in adverse reactions and there were no deaths reported.

1. Types of errors

1.1. Coding of Transfusion Errors

Errors captured through the TESS are of different types (Table 1) depending on where they occurred in the blood transfusion chain (Figure 1) and when they are discovered (either before or after the actual transfusion). For instance, distributor code (DC) errors can originate from blood suppliers, which in the TESS context include not only the Canadian Blood Services (CBS) and Héma-Québec (HQ), but also hospitals of larger capacity that serve as intermediary between the blood suppliers and hospitals of smaller capacity. Those involving sample collection (SC) usually occur on hospital wards in general compared to sample receipt (SR) and sample testing (ST) errors that will only occur in the transfusion laboratory where testing takes place. Errors like those involving sample handling (SH) or unit storage (US) errors could occur at multiple locations in the blood transfusion chain (Figure 1). Within each type of errors, specific errors were assigned numerical codes and the complete list of these codes is available in the surveillance manual and can be provided upon request.

1.2. Calculation of the Occurrence Rates of Transfusion Errors

Annual rates of occurrence of errors involving DC, PC, US, IM, PR, RP, PS, UM, UI and UT were calculated using the total units of product received, requested, prepared or issued per surveillance year as denominator (Table 1). For errors related to sample collection (SC), sample handling (SH), and sample receipt (SR), the corresponding denominator was the total number of samples received during the surveillance year, whereas for sample testing (ST) errors, it was the total number of tests performed.

Overall, a total of 625,907 blood samples were received by the laboratories where over a million and two hundred thousand tests were performed (Tables 2A & 2B). In parallel, blood banks of the TESS network received over 881,366 requests for blood components and blood products and issued a total of 859,624. Since 2009, the number of samples received, and the numbers of units of product requested and received have been decreasing gradually. At the same time, that of the tests performed has been increasing after a 25% decrease in 2009 (Table 2A). Table 2B displays the breakdown of the denominator data by the different categories of hospitals defined by the volume of transfusions preformed per year.

Table 1. General error codes & corresponding denominator data, TESS 2008-2011
Error code Type of error Description Corresponding denominator
DC Distributor codes
  • Errors occurring at the supplier level (including blood manufacturers)
Units of product received
PC Product check-in
  • Errors that relate to putting products into inventory from the Blood Centre, another site/campus or return from the ward.
US Unit storage
  • Errors related to incorrect storage of blood products/components within the transfusion service
IM Inventory Management
  • Errors related to inventory management
PR Product request
  • Errors related to placing an order/request for a product/test
Units of product requested
RP Request for pick-up
  • Errors related to picking up blood products/ components for transfusion
PS Product selection
  • Production selection errors
Units of product prepared
UM Unit manipulation
  • Processing errors (pooling, irradiation, …)
UI Unit issued
  • Wrong product issued
  • Product issued to wrong patient
Units of product issued (by Blood Bank)
UT Unit transfusion
  • Wrong product administered;
  • Product administered to wrong  patient
SC Sample collection
  • Errors that relate to collecting or labelling specimen tubes
Samples received
SH Sample handling
  • Errors related to managing requisition
  • Transportation errors
SR Sample receipt
  • Errors related to receipt of samples in the laboratory
ST Sample testing
  • Testing errors
Tests performed (including screening)
MS Miscellaneous
  • Errors not related to any of those listed above (e.g. incomplete/ incorrect patient registration, …)
-

Table 2A. Denominator data for the various types of errors, TESS 2008-2011
  2008 2009 2010 2011 Total
Total number of samples received 166,703 169,942 149,945 139,317 625,907
Total number of tests performed 359,740 270,706 277,039 294,944 1,202,429
Total units of products received 231,042 230,572 210,846 206,866 879,326
Total units of products requested 221,226 228,817 218,882 212,441 881,366
Total units of products prepared 233,142 239,239 237,203 249,635 959,219
Total units of products issued 214,850 223,115 215,836 205,823 859,624

Table 2B. Denominator data by the transfusion capacity of reporting hospitals, TESS 2008-2011
  Hospitals of small capacity
(< 2,000 blood component transfusions)
Hospitals of medium capacity
(2,000 to 10,000 blood component transfusions)
Hospitals of large capacity
(>10,000 blood component Transfusions)
Total
Total number of samples received 52,218 207,668 366,021 625,907
Total number of tests performed 48,969 336,516 816,944 1,202,429
Total units of products received 25,339 234,864 619,123 879,326
Total units of products requested 19,926 239,668 621,772 881,366
Total units of products prepared 20,542 283,842 654,835 959,219
Total units of products issued 18,527 234,389 606,708 859,624



Figure 1. Blood Transfusion Chain: Transfusion Process & types of errors associated with each step

Figure 1
Text Equivalent - Figure 1

The transfusion chain described in Figure 1 indicates where each category of errors occurs. They are errors that occur only in laboratory (blood suppliers, laboratory services, supplier/ service providers or transfusion services) or clinical settings (i.e. hospital units/wards where patients receive transfusion care: operating room, emergency room, outpatient clinic, intensive care unit, obstetrics, etc.) and errors that can occur in both. DC, PC, IM, SR, ST, UI and UM errors occur only in laboratory setting while errors related to SC or UT only occur in clinical setting.

Enlarge Figure 1

N.B. * Miscellaneous (MS) errors can be captured outside of the standardized codes presented in this figure.

Overall, 34,088 transfusion errors met the surveillance criteria and of these, the most common were related to the collections (n=13,680) and handling (n=3,547) of blood samples which accounted for over 50% of the cases (Figure 2). Errors involving unit transfusions (n=3,013), product requests (n=2,673), sample receipt (n=2,124) and sample testing (n=2,476) constituted the second most frequent groups and accounted for over 39% of the cases (Figure 3). The least common of all the errors were those related to product storage (Figure 2) as only 70 cases were reported for the entire 2008-2011 period (Figure 2).

Figure 2. Annual frequency of transfusion errors by type (n=34,088), TESS 2008-2011

Figure 2
Text Equivalent - Figure 2
  2008 (n=8,395) 2009 (n=8,253) 2010 (n=8,917) 2011 (n=8,523)
DC (n=1,742) 339 420 554 429
PC (n=1,482) 599 429 254 200
US (n=70) 21 14 19 16
IM (n=160) 47 36 39 38
SC (n=13,680) 2,938 3,241 3,344 4,157
SH (n=3,547) 756 808 1,021 962
SR (n=2,124) 871 631 409 213
ST (n=2,476) 718 622 855 281
PR (n=2,673) 617 569 680 807
PS (n=113) 22 45 35 11
UM (n=522) 146 168 105 103
UI (n=445) 129 116 117 83
RP (n=914) 244 222 226 222
UT (n=3,013) 538 612 1,001 862
MS (n=1,127) 410 320 258 139

Overall, 34,088 transfusion errors met the surveillance criteria and of these, the most common were related to the collections (n=13,680) and handling (n=3,547) of blood samples which accounted for over 50% of the cases (Figure 2). Errors involving unit transfusions (n=3,013), product requests (n=2,673), sample receipt (n=2,124) and sample testing (n=2,476) constituted the second most frequent groups and accounted for over 39% of the cases (Figure 3). The least common of all the errors were those related to product storage (Figure 2) as only 70 cases were reported for the entire 2008-2011 period (Figure 2).

Enlarge Figure 2

The number of errors related to sample collection (n=13,680) has been increasing significantly (p<0.05) over time (Figure 3). The most common of these errors (Table 3) have been haemolysis of samples (34.9%), labelingFootnote 1 (34.9%), and unnecessary collections (21.7%). Locations which reported highest numbers (Table 3) included emergency rooms (39.7%), medical/surgical wards (29.8%), and outpatient clinics (13.3%).

Table 3. Sub-categories of sample collection errors by discovery location, TESS 2008-2011
Sample collection Errors Transfusion Service Supplier/ Service provider Laboratory service Medical/ Surgical Ward Emergency Room Outpatient clinic Intensive care unit Operating Room Obstetrics unit Recovery room Overall
Freq. % Freq. % Freq. % Freq. % Freq. % Freq. % Freq. % Freq. % Freq. % Freq. % Freq. %
  • SC 01 = Sample labelled with wrong patient identification
  • SC 02 = Not labelled
  • SC 03 = Wrong patient collected (not from intended patient)
  • SC 04 = Collected in wrong tube type
  • SC 05 = NSQ (Non-Sufficient Quantity) sample
  • SC 06 = Sample haemolysed
  • SC 07 = Label incomplete / illegible for key patient identifiers (name, identification, birthdate)
  • SC 08 = Sample collected unnecessarily
  • SC 09 = Requisition arrives without samples
  • SC 10 = Armband incorrect / not available
  • SC 12 = Label incomplete / illegible for non-key patient identifiers
  • SC 99 = Other
SC 01 0 0.0% 2 0.0% 0 0.0% 45 0.3% 44 0.3% 48 0.4% 27 0.2% 10 0.1% 67 0.5% 0 0.0% 243 1.8%
SC 02 0 0.0% 1 0.0% 0 0.0% 91 0.7% 109 0.8% 50 0.4% 74 0.5% 12 0.1% 42 0.3% 0 0.0% 379 2.8%
SC 03 0 0.0% 0 0.0% 0 0.0% 32 0.2% 38 0.3% 13 0.1% 9 0.1% 1 0.0% 12 0.1% 0 0.0% 105 0.8%
SC 04 0 0.0% 0 0.0% 0 0.0% 157 1.1% 83 0.6% 50 0.4% 85 0.6% 10 0.1% 48 0.4% 1 0.0% 434 3.2%
SC 05 0 0.0% 0 0.0% 0 0.0% 33 0.2% 106 0.8% 7 0.1% 6 0.0% 0 0.0% 8 0.1% 0 0.0% 160 1.2%
SC 06 0 0.0% 1 0.0% 0 0.0% 746 5.5% 3,120 22.8% 452 3.3% 205 1.5% 167 1.2% 79 0.6% 2 0.0% 4,772 34.9%
SC 07 0 0.0% 1 0.0% 6 0.0% 697 5.1% 508 3.7% 273 2.0% 248 1.8% 57 0.4% 91 0.7% 1 0.0% 1,882 13.8%
SC 08 1 0.0% 0 0.0% 0 0.0% 1,336 9.8% 773 5.7% 264 1.9% 309 2.3% 97 0.7% 188 1.4% 0 0.0% 2,968 21.7%
SC 09 0 0.0% 0 0.0% 1 0.0% 42 0.3% 60 0.4% 39 0.3% 41 0.3% 1 0.0% 7 0.1% 0 0.0% 191 1.4%
SC 10 0 0.0% 0 0.0% 0 0.0% 5 0.0% 3 0.0% 16 0.1% 1 0.0% 0 0.0% 1 0.0% 0 0.0% 26 0.2%
SC 12 2 0.0% 3 0.0% 5 0.0% 850 6.2% 539 3.9% 524 3.8% 191 1.4% 49 0.4% 65 0.5% 0 0.0% 2,228 16.3%
SC 99 1 0.0% 1 0.0% 0 0.0% 44 0.3% 48 0.4% 79 0.6% 29 0.2% 54 0.4% 35 0.3% 1 0.0% 292 2.1%
Total 4 0.0% 9 0.1% 12 0.1% 4,078 29.8% 5,431 39.7% 1,815 13.3% 1,225 9.0% 458 3.3% 643 4.7% 5 0.0% 13,680 100%

1. Occurrence and discovery locations of errors reported through the TESS from 2008 to 2011

Over 98% (N=33,622) of all reported transfusion errors were detected before transfusion (Figure 3), therefore did not cause any harm to the patients. This shows a robust system with checks and balances in place in Canadian hospitals participating in the TESS.

Figure 3. Frequency of transfusion errors by processes during which they were discovered, TESS 2008-2011

Figure 3
Text Equivalent - Figure 3
  2008 2009 2010 2011
Product Check-in 859 776 734 618
Product storage 5 7 31 14
Before testing patient sample 4,334 4,606 4,845 5,582
During/After patient test verified/ before cross-match 1,318 1,140 1,211 549
During cross-match/ processing 515 560 810 588
After cross-match/ processing before issue 528 373 132 102
After cross-match/ processing at issue 245 215 241 201
After issue, but before infusion 481 436 780 781
Subsequent patient test 2 1 1 1
After infusion 108 139 132 87

Over 98% (N=33,622) of all reported transfusion errors were detected before transfusion (Figure 3), therefore did not cause any harm to the patients. This shows a robust system with checks and balances in place in Canadian hospitals participating in the TESS.

Enlarge Figure 3

Transfusion service reported the highest proportion of errors (22.5%) and the highest detection rate (95.4%) as displayed in Table 3. The vast majority of errors occurring in other settings (87.5% to 98.1%) were detected by the transfusion service (Table 3).

Table 4. Occurrence & discovery locations of transfusion errors (n=34,088), TESS 2008-2011
  Discovery location
Occurrence location Transfusion service Blood Supplier Supplier / Service provider Laboratory service Medical/ Surgical unit Emergency Room Outpatient clinic Intensive care unit Operating Room Obstetrics unit Recovery room Total
Transfusion Service 7,354 7 12 6 71 14 92 36 60 11 3 7,666
Blood Supplier 1,297 10 0 0 22 5 21 12 11 0 0 1,378
Supplier/Service provider 380 5 1 1 4 4 3 3 1 0 0 402
Laboratory Service 111 0 0 5 2 0 0 2 0 0 0 120
Medical/ Surgical Unit 6,864 0 0 7 261 0 6 2 4 0 0 7,144
Emergency Room 6,920 0 1 5 10 122 1 3 3 0 0 7,065
Outpatient Clinic 3,901 0 0 2 1 0 140 0 6 0 1 4,051
Intensive care Unit 2,868 0 2 6 1 2 0 387 1 0 0 3,267
Operating Room 1,430 0 0 5 1 0 0 5 126 0 4 1,571
Obstetrics Unit 1,365 0 0 6 1 0 1 0 0 19 0 1,392
Recovery Room 28 0 0 0 1 0 0 1 0 0 2 32
Total 32,518 22 16 43 375 147 264 451 212 30 10 34,088

2. Errors Discovered after Transfusion, TESS 2008 - 2011

Overall, 466 (1.4%) transfusion errors reported through the TESS between 2008 and 2011were discovered after the actual transfusion (Figure 3). Errors related to storage (n=1) and requests for pick-up of blood components/products (n=1) were the fewest and occurred respectively once per 879,326 or 881,366 units of products requested; whereas those related to unit transfusions (n=278) were the most frequent with an occurrence rate of 1 per 3,092 units of products transfused (Table 5A).  However, the frequency of unit transfusion errors discovered after transfusion has been decreasing significantly (p<0.05) after a substantial 50% increase in 2009 (Table 5A). In 2010, it decreased by 16% and the following year by 33% (Table 5A).

Table 5A. Rate of occurrence of errors discovered only AFTER (n=466) transfusion, TESS 2008-2011
Error codeTable 5A - Footnote 1 2008 2009 2010 2011 Total
Freq. Rate per 100,000 Risk of one error Freq. Rate per 100,000 Risk of one error Freq. Rate per 100,000 Risk of one error Freq. Rate per 100,000 Risk of one error Freq. Rate per 100,000 Risk of one error
1Description of error codes available in Table 1
2Risk for MS & overall errors could not be calculated due to the lack of corresponding appropriate denominators
DC 0 0 - 0 0 - 2 1 1: 105,423 0 0 - 2 0 1: 439,663
PR 18 8 1: 12,290 12 5 1: 19,068 16 7 1: 13,680 18 8 1: 11,802 64 7 1: 13,771
RP 1 0 1: 221,226 0 0 - 0 0 - 0 0 - 1 0 1: 881,366
PC 2 1 1: 115,521 0 0 - 0 0 - 1 0 1: 206,866 3 0 1: 293,109
US 0 0 - 1 0 1: 230,572 0 0 - 0 0 - 1 0 1: 879,326
IM 2 1 1: 115,521 0 0 - 2 1 1: 105,423 3 1 1: 68,955 7 1 1: 125,618
UM 1 0 1: 233,142 0 0 - 4 2 1: 59,301 1 0 1: 249,635 6 1 1: 159,870
PS 1 0 1: 233,142 7 3 1: 34,177 4 2 1: 59,301 1 0 1: 249,635 13 1 1: 73,786
UI 10 5 1: 21,485 14 6 1: 15,937 11 5 1: 19,621 8 4 1: 25,728 43 5 1: 19,991
UT 63 29 1: 3,410 95 43 1: 2,349 78 36 1: 2,767 42 20 1: 4,901 278 32 1: 3,092
SH 1 1 1: 166,703 2 1 1: 84,971 3 2 1: 49,982 1 1 1: 139,317 7 1 1: 89,415
SR 4 2 1: 41,676 5 3 1: 33,988 7 5 1: 21,421 6 4 1: 23,220 22 4 1: 28,450
ST 5 3 1: 33,341 3 2 1: 56,647 5 3 1: 29,989 4 3 1: 34,829 17 3 1: 70,731
MSTable 4A - Footnote 2 0 - - 0 - - 0 - - 2 - - 2 - -
TotalTable 4A - Footnote 2 108 - - 139 - - 132 - - 87 - - 466 - -

Table 5B. Rate of occurrence of errors discovered only AFTER (n=466) transfusion, TESS 2008-2011
Error codeTable 5B - Footnote 1 Small
(less than 2,000 transfusions per year)
Medium
(between 2,000 & 10,000 transfusions per year)
Large
(more than 10,000 transfusions per year)
Total
Freq. Rate per 100,000 Risk of one error Freq. Rate per 100,000 Risk of one error Freq. Rate per 100,000 Risk of one error Freq. Rate per 100,000 Risk of one error
1Description of error codes available in Table 1
DC 0 0.0 - 2 0.9 1: 117,432 0 0.0 - 2 0.2 1: 439,663
PR 3 15.1 1: 6,642 5 2.1 1: 47,934 56 9.0 1: 11,103 64 7.3 1: 13,771
RP 0 0.0 - 0 0.0 - 1 0.2 1: 621,772 1 0.1 1: 881,366
PC 0 0.0 - 0 0.0 - 3 0.5 1: 206,374 3 0.3 1: 293,109
US 0 0.0 - 0 0.0 - 1 0.2 1: 619,123 1 0.1 1: 879,326
IM 2 7.9 1: 12,670 3 1.3 1: 78,288 2 0.3 1: 309,562 7 0.8 1: 125,618
UM 0 0.0 - 4 1.4 1: 70,961 2 0.3 1: 327,418 6 0.6 1: 159,870
PS 0 0.0 - 3 1.1 1: 94,614 10 1.5 1: 65,484 13 1.4 1: 73,786
UI 2 10.8 1: 9,264 11 4.7 1: 21,308 30 4.9 1: 20,224 43 5.0 1: 19,991
UT 4 21.6 1: 4,632 192 81.9 1: 1,221 82 13.5 1: 7,399 278 32.3 1: 3,092
SH 0 0.0 - 0 0.0 - 7 1.9 1: 52,289 7 1.1 1: 89,415
SR 0 0.0 - 4 1.9 1: 51,917 18 4.9 1: 20,335 22 3.5 1: 28,450
ST 0 0.0 - 3 0.9 1: 112,172 14 1.7 1: 58,353 17 1.4 1: 70,731
MS 0 - - 0 - - 2 - - 0 - -
Total 11 - - 227 - - 228 - - 466 - -

Table 5B provides the rate of each of the errors discovered after transfusion by the hospitals’ capacity. For example, errors related to UT occurred at different frequencies depending on the type of hospitals: they were rare in hospitals of large capacity (one in 7,399 units of products issued against one in 4,632 or one in 1,221 respectively in hospitals of low and medium capacity (Table 5B).

Figure 4. Location of occurrence of errors discovered AFTER transfusion (n=466), TESS 2008-2011

Figure 4
Text Equivalent - Figure 4
  2008 (n=108) 2009 (n=139) 2010 (n=132) 2011 (n=87)
Supplier/Service provider (n=2) 0 1 1 0
Blood Supplier (n=1) 0 0 1 0
Transfusion Service (n=114) 26 30 33 25
Intensive Care Unit (n=137) 40 54 29 14
Medical/ Surgical Ward (n=81) 19 23 22 17
Operating Room (n=62) 10 20 26 6
Emergency Room (n=43) 8 6 15 14
Outpatient Unit (n=25) 4 5 5 11
Obstetrics Unit (n=1) 1 0 0 0

The majority of errors discovered after the actual blood transfusion originated from intensive care units (n=137), transfusion services (n=114), medical/surgical wards (n=81) and operating rooms (n=62).  Also, after peaking at a total of 139 cases in 2009, the number of these errors did not change until 2011 when it declined significantly (p<0.01) from 132 to 87. Operating rooms and intensive care units recorded highest (p<0.01) decreases: 77% (from 26 cases in 2010 to six in 2011) and 52% (from 29 cases in 2010 to 14 in 2011), respectively (Figure 4).

Enlarge Figure 4

The majority of errors discovered after the actual blood transfusion originated from intensive care units (n=137), transfusion services (n=114), medical/surgical wards (n=81) and operating rooms (n=62).  Also, after peaking at a total of 139 cases in 2009, the number of these errors did not change until 2011 when it declined significantly (p<0.01) from 132 to 87. Operating rooms and intensive care units recorded highest (p<0.01) decreases: 77% (from 26 cases in 2010 to six in 2011) and 52% (from 29 cases in 2010 to 14 in 2011), respectively (Figure 4).

Figure 5. Detection timeline (time delay between occurrence & detection) of errors discovered AFTER (n=466) transfusion, TESS 2008 – 2011

Figure 5
Text Equivalent - Figure 5
  2008 (n=108) 2009 (n=139) 2010 (n=132) 2011 (n=87)
Same day (n=162) 40.7% 22.3% 35.6% 46.0%
Next day (n=99) 20.4% 16.5% 25.8% 23.0%
2-3 days (n=78) 23.1% 20.9% 10.6% 11.5%
4-7 days (n=55) 7.4% 15.8% 13.6% 8.0%
8-14 days  (n=35) 4.6% 14.4% 5.3% 3.4%
15-30 days (n=37) 3.7% 10.1% 9.1% 8.0%

Overall same-day detection rate of transfusion errors discovered after transfusion had occurred, ranged from 22.3% in 2009 to 46.0% in 2011 (Figure 5). It initially sharply declined from 40.7% in 2008 to 22.3% in 2009 and has significantly (p=0.05) been increasing since then. This is an indication that hospitals participating in the TESS are continuously making efforts to ensure transfusion safety.

Enlarge Figure 5

Overall same-day detection rate of transfusion errors discovered after transfusion had occurred, ranged from 22.3% in 2009 to 46.0% in 2011 (Figure 5). It initially sharply declined from 40.7% in 2008 to 22.3% in 2009 and has significantly (p=0.05) been increasing since then. This is an indication that hospitals participating in the TESS are continuously making efforts to ensure transfusion safety.

Over 82% (n=385) of the errors discovered after transfusion were errors related to requests (PR), issuance (UI) and transfusion (UT) of products (Figure 6). Unlike PR-related errors most of which were detected within 24 hours of their occurrence (56.3%), most of UI (53.5%) and UT (69.8%) errors were detected only a day or more after they had occurred (Figure 6).

Figure 6. Detection timeline of different types of errors discovered AFTER (n=466) transfusion, TESS 2008-2011

Figure 6

Text Equivalent - Figure 6

Over 82% (n=385) of the errors discovered after transfusion were errors related to requests (PR), issuance (UI) and transfusion (UT) of products (Figure 6). Unlike PR-related errors most of which were detected within 24 hours of their occurrence (56.3%), most of UI (53.5%) and UT (69.8%) errors were detected only a day or more after they had occurred (Figure 6).

Enlarge Figure 6

3. Potential Severity of Errors Discovered after Transfusion (n=466), TESS 2008 - 2011

The majority (n=392) of errors discovered after blood transfusion were of potential low severity (Figure 7). However, the proportion has incrementally been decreasing in favour of the potential high severity group which started at 11% in 2008 and has since reached almost 20% (Figure 7).

Figure 7. Potential severity of errors discovered AFTER (n=466) transfusion, TESS 2008 - 2011

Figure 7
Text Equivalent - Figure 7
  2008 (n=108) 2009 (n=139) 2010 (n=132) 2011 (n=87)
Low (n=392) 85.2% 88.5% 84.1% 75.9%
Medium (n=8) 3.7% 0.0% 0.0% 4.6%
High (n=66) 11.1% 11.5% 15.9% 19.5%

The majority (n=392) of errors discovered after blood transfusion were of potential low severity (Figure 7). However, the proportion has incrementally been decreasing in favour of the potential high severity group which started at 11% in 2008 and has since reached almost 20% (Figure 7).

Enlarge Figure 7

Only eight (1.7%) of these errors were assigned medium level of potential severity (Figures 8 & 9): these were errors related to unit transfusions (n=5), product requests (n=2) and units issued (n=1).

Figure 8. Type of errors detected AFTER transfusion (n=466) by level of potential severity, TESS 2008 - 2011

Figure 8
Text Equivalent - Figure 8

Only eight (1.7%) of these errors were assigned medium level of potential severity (Figures 8 & 9): these were errors related to unit transfusions (n=5), product requests (n=2) and units issued (n=1).

Potential high severity errors discovered after the actual transfusion (n=66) were primarily related to requests (n=12), issuance (n=21) and transfusion (n=30) of products (Figures 8 & 9). The most common of the subtypes were issuing (UI 19) and administering (UT 02) wrong products to the patients which together accounted for 50% of the 66 cases.

Enlarge Figure 8

4. Potential High Severity Errors Discovered after Transfusion (n=66), TESS 2008 - 2011

Potential high severity errors discovered after the actual transfusion (n=66) were primarily related to requests (n=12), issuance (n=21) and transfusion (n=30) of products (Figures 8 & 9). The most common of the subtypes were issuing (UI 19) and administering (UT 02) wrong products to the patients which together accounted for 50% of the 66 cases.

Figure 9. Errors of potential high severity errors discovered AFTER (n=66) transfusion, TESS 2008-2011

Figure 9

Text Equivalent - Figure 9

Only eight (1.7%) of these errors were assigned medium level of potential severity (Figures 8 & 9): these were errors related to unit transfusions (n=5), product requests (n=2) and units issued (n=1).

Potential high severity errors discovered after the actual transfusion (n=66) were primarily related to requests (n=12), issuance (n=21) and transfusion (n=30) of products (Figures 8 & 9). The most common of the subtypes were issuing (UI 19) and administering (UT 02) wrong products to the patients which together accounted for 50% of the 66 cases.

Enlarge Figure 9

The overall same-day detection rate for errors of potential high severity discovered after transfusion was 53% (Figure 10) and had gradually declined from 66.7% in 2008 to 47.1% in 2011 (Figures 11A-D).

Figure 10. Detection timeline of potential high severity errors discovered AFTER (n=66) transfusion, TESS 2008-2011

Figure 10
Text Equivalent - Figure 10

The overall same-day detection rate for errors of potential high severity discovered after transfusion was 53% (Figure 10) and had gradually declined from 66.7% in 2008 to 47.1% in 2011 (Figures 11A-D).

Enlarge Figure 10

Figure 11A. Detection timeline of potential high severity of errors discovered AFTER transfusion (n=12), TESS 2008

Figure 11A
Text Equivalent - Figure 11A

Same-day detection rate was 66.7% (Figure 11A). Four cases of PR 06 and UI 19 went undetected for more than 24 hours.

Enlarge Figure 11A

Same-day detection rate was 66.7% (Figure 11A).
Four cases of PR 06 and UI 19 went undetected for more than 24 hours.

Figure 11B. Detection timeline of potential high severity of errors discovered AFTER transfusion (n=16), TESS 2009

Figure 11B

Text Equivalent - Figure 11B

Same-day detection rate was 50.0% (Figure 11B).
Four cases were detected a day later and another four 2-7 days later (Figure 11B).

Enlarge Figure 11B

Same-day detection rate was 50.0% (Figure 11B).
Four cases were detected a day later and another four 2-7 days later (Figure 11B).

Figure 11C. Detection timeline of potential high severity of errors discovered AFTER transfusion (n=21), TESS 2010

Figure 11C
Text Equivalent - Figure 11C

Same-day detection rate was 52.4% (Figure 11C). Eight cases were detected within the following three days, and the remaining two more than a week later (Figure 11C).

Enlarge Figure 11C

Same-day detection rate was 52.4% (Figure 11C).
Eight cases were detected within the following three days, and the remaining two more than a week later (Figure 11C).

Figure 11D. Detection timeline of potential high severity of errors discovered AFTER transfusion (n=17), TESS 2011

Figure 11D
Text Equivalent - Figure 11D

Same-day detection rate was 47.1% (Figure 11D). Four cases were detected a day later, another four within a week, and the remaining five within a week (n=4) or two (n=1).

Enlarge Figure 11D

Same-day detection rate was 47.1% (Figure 11D).
Four cases were detected a day later, another four within a week, and the remaining five within a week (n=4) or two (n=1).

5. Outcome of Transfusion Errors

The overwhelming majority (n=33,622) of the transfusion errors reported through the TESS network between 2008 and 2011 were discovered before the actual transfusion of blood products/components and therefore, had no negative impact on the patient’s health.  Similarly, errors of low (n=392) and medium (n=8) potential severity discovered after transfusion had occurred caused no harm to the patients involved. Only some high potential severity errors discovered after transfusion negatively impacted the health of the patients involved. Of the 66 such cases, 16 (24.2%) were found to be associated with adverse events (Table 6) that included transfusion related circulatory overload (n=8), febrile non-hemolytic (n=2) and mild (n=1) reactions, as well as adverse reactions unspecified nature (n=5), but definitely related to transfusion. Transfusion related circulatory overload was caused by inappropriate/incorrect/no order of blood product or blood component (n=6) and not following guidelines for infusion time (n=2), which were also causes for the single mild adverse reaction reported and one of the two cases of febrile non-hemolytic reaction (Table 6), the other case of febrile non-hemolytic reaction resulted from the transfusion of a product with an incompatible IV fluid. However, none of all these adverse reactions resulted in death (Table 6).

Table 6. Specific errors that resulted in adverse reactions, TESS 2008-2011
Transfusion error Transfusion-associated circulatory overload
(CQ 03)
Febrile non-hemolytic
(CQ 03)
Mild transfusion reaction
(CQ 03)
Transfusion reaction of unspecified nature
(CQ 03)
Total
Description Code
Incorrect/no product order PR 04 1 0 0 0 1
Inappropriate product order PR 06 5 1 0 2 8
Incorrect/no historical review SR 02 0 0 0 1 1
Wrong product issued to a patient UI 19 0 0 0 2 2
Administration of product with incompatible fluid UT 06 0 1 0 0 1
Guidelines for infusion time not followed UT 25 2 0 1 0 3
Total - 8 2 1 5 16

6. Conclusion

In conclusion, of the total 34,088 errors reported during the 2008 to 2011 time period, there were only 16 errors (1.4%) that resulted in adverse reactions and there were no deaths reported. Although a few errors of potential high severity did result in adverse transfusion reactions that impacted the patients’ health, the vast majority of errors were detected before transfusion and resulted in no adverse reactions. Monitoring of transfusion errors as well as a regular review of prevention and safety Standard Operating Procedures (SOPs) in the blood transfusion chain are important to ensure patient safety, particularly where it relates to product requests/order, issuance and transfusion of blood components/products.


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