Human Error Is Inevitable

 A Proactive Approach to Transfusion Safety

We are all afraid of serious blood bank errors. Transfusion medicine is one of the few areas in a laboratory where a mistake can kill a patient. As you learn the reason for the critical error, it may seem obvious how to redesign the process — but why not before? This article describes a proactive approach, using the Blood Loc barrier system as an example.

Most serious blood bank errors are caused by patient misidentification, leading to sample mislabeling, wrong blood in the tube (WBIT) or the wrong unit transfused. A 2010 report by the Pennsylvania Patient Safety Advisory (PPSA) states, “Blood component transfusions to unintended recipients occur in about 1 out of 10,000 transfused units, and two-thirds of these errors are associated with incorrect blood recipient identification that occurs at the patient’s bedside.” This occurs most commonly during sample collection (61 percent) but also during transfusion (12 percent of reactions attributed to administering incorrect blood).1

The pre-analytical rate is alarmingly high. A College of American Pathologists
(CAP) Q-Probes study of specimens submitted for ABO typing reports a 1.12 percent error rate of mislabeling or WBIT. While respondent practice varied on how to handle these errors or what to do in the absence of a historical type, almost all allowed collection and labeling by non-laboratory personnel, which is seen as a major risk factor according to study co-author Christopher Lehman, MD.2

But post-analytical errors, also outside laboratory’s direct control, are significant. The New York Timesreports a “chain of errors” involving a head nurse, staff nurse, nursing supervisor and laboratory technician who failed to follow detailed procedures. In this case, two nurses administering the blood failed to double-check information on a wristband with information on the unit, giving blood to the wrong patient.3

We believe human error is inevitable and eliminated through engineering. For example, an automated cell counter eliminates human error in performing hemocytometer chamber counts. Human technologists can delay testing (causing the chamber to dry and falsely elevating the count), miscount cells, count cells inconsistently and make calculation errors. The higher the technologist’s stress level and the more distracted; the greater the risk.

But are people responsible for human error? Human error can be viewed, as pointed out by author James Reason in Western Journal of Medicine, as a person or a system problem. The former, which dominates medicine, blames individuals for being forgetful, inattentive, unmotivated, careless, negligent or reckless. The latter concludes human error is a consequence and not a cause of events. A systems approach acknowledges that dangerous errors can occur and tries to mitigate their effects when they do happen, rather than blaming and shaming people.4

Try To Break It

A good approach is to try to break a process before a real event does. A failure mode and effects analysis (FMEA) is one proactive tool to identify potential events that can harm patients. This is radically different from the traditional healthcare approach, in which root cause analysis is performed after sentinel events, medical errors and other mistakes. As Dr. Deborah L. Smith writes, “it is important to analyze information from a prospective point of view to see what could go wrong before the adverse event occurs.”5

A FMEA team to analyze the transfusion service needs to be multidisciplinary and cross-functional. Basic steps include identifying the scope of the FMEA using flowcharts, if needed; identifying all functions within that scope (what are the steps?); identifying all ways failure could happen for each function (what can go wrong?); and, for each failure mode, identifying all consequences on the system, related systems, process, related processes, product, service, customer or regulations (what happens when something goes wrong?). Root causes (why do things go wrong?), controls and recommendations are prioritized.6

FMEA steps are workable within a narrow scope and small teams of three to six people. An online tool is available on the Institute for Healthcare Improvement website.7

A Practical Example

If your organization’s leadership has not invested in quality tools such as FMEA, a proactive laboratory approach can still be successful. The same concepts apply: a multidisciplinary team asking what can go wrong and analyzing what happens when something does go wrong.

When a unit of blood is picked up by nursing to be administered to a patient, for example, it leaves laboratory control. A team of laboratory technologists and nurses can rapidly identify a critical point of possible failure: misidentification of the patient prior to administration.

  • What can go wrong? Misidentification can happen from a number of root causes (duplicate names, missing wristband, wrong wristband, multiple patients being transfused, etc.). Variation in identifiers may be prioritized as the most important.
  • What happens when the wrong unit is transfused? Events can range from undetectable (two thirds of the time units are ABO compatible) to immediate (brisk hemolytic reaction) to severe injury to patient death.

A mechanical barrier is one approach to standardize identification. As Ellen LaChance, MS, MT(ASCP)SBB, reports in CLP in 2013, “Mechanical barriers are designed to force the patient identity check immediately before a transfusion… The mechanical barrier product is simply a lock put on a zip-top overbag that contains the appropriately labeled blood component intended for transfusion.”8

A combination code is attached to the patient wristband prior to specimen collection, and the bag and lock are prepared by the laboratory prior to releasing the unit. Nursing only unlocks the unit with the correct code on the correct wristband, closing the loop from collection to administration. Barrier products, such as Blood Loc (Novatek Medical), are effectively used in many institutions to reduce the chance of patient misidentification. LaChance advises a strong culture of safety, procedures for exceptions (wristband is cut off, etc.) and different specimen sources.

A proactive laboratory approach that works across departments can make transfusions safer. By identifying points of failure in a system that cause human error, the process can be designed to be more robust, less likely to fail and the effects of failure will be more controlled, leading to better patient care.


  1. Improving the Safety of the Blood Transfusion Process.  2010. Available at:
  2. Ford A. College of American Pathologists – Disabling mislabeling solutions for blood banks. Caporg. 2009. Available at:
  3. Kennedy R. Hospital Is Fined by State For 6 Transfusion Errors. Nytimescom. 1995. Available at:
  4. Reason J. Human error: models and management. Western Journal of Medicine. 2000;172(6):393. Available at:
  5. Smith MD D. FMEA: Preventing a Failure Before Any Harm Is Done. Isixsigmacom. Available at:
  6. Tague N. Failure Mode Effects Analysis (FMEA) – ASQ. Asqorg. 2004. Available at:
  7. Institute for Healthcare Improvement: Failure Mode and Effects Analysis (FMEA) Tool.  2015. Available at:
  8.  LaChance E. Web-Exclusive: Mechanical Barriers: A Simple Approach to Preventing Transfusion Errors – Clinical Lab Products. Clinical Lab Products. 2013. Available at: