Volume 37 Number 6 | December 2023
Sarah Bergbower, DCLS, MLS(ASCP)CM, ASCLS Today Volunteer Contributor
As a Doctor of Clinical Laboratory Science (DCLS), I am often interested in the medical laboratory science professional’s role in identifying and limiting pre-pre- and post-post-analytical errors. Defined by Laposata and Dighe, “pre-pre” analytical errors result from inappropriate test selection, and “post-post” analytical errors stem from a misinterpretation that leads to misdiagnosis or improper treatment.1 When reflecting on such incidents, we can often identify multiple points at which failure occurred, as well as the factors at various levels of the system that contributed to these failures. Filling out yet another incident report sometimes feels like tattling, and while it is not about finger-pointing, an imperative cognizance of where safety gaps lie ultimately drives better patient safety upon their repair.
The following is a story that I frequently share as an example of a pre-pre-analytical error that I experienced during my shift as a medical laboratory scientist in a rural hospital lab one night.
“This pre-pre-analytical error could have cost this patient their life had the laboratory not realized the wrong test was ordered.”
A patient was being seen in the emergency department (ED) and had several types of specimens, including blood, urine, cerebral spinal fluid (CSF), and stool, sent to the laboratory for various tests. We received an order for the detection of Cryptosporidium. Minutes after I requisitioned the patient’s pre-collected stool sample from the refrigerator, my colleague approached me with a completed Cryptococcus agglutination assay that she had quickly and diligently started with the patient’s CSF.
As a brief review, these are very different organisms causing very different symptoms that are tested very differently on very different types of samples. Cryptosporidium is a protozoan that causes diarrhea and abdominal discomfort, while Cryptococcus is a yeast that causes meningitis. Seeing an order for a “STAT CRYPTO” appear on the stat-board’s television screen, my colleague jumped to test the CSF for meningitis. “Does this look positive to you?” she asked in disbelief. “Yes,” I replied, “but that’s Cryptococcus, not Cryptosporidium.”
What did the ED physician really mean to order? Had I continued to follow the order, this patient’s outcome would have been very different and severely adverse. I remember the horrified looks my colleague and I exchanged as we realized the CSF was positive for Cryptococcus, and we called the ED to have them change the order immediately so the findings could be reported in the EMR.
Had it not been for my colleague’s “mistake” and subsequent assumption of an incorrectly ordered test, this patient’s physician would have received a “negative” test result, and the patient’s meningitis would have gone misdiagnosed and unresponsive to typical empiric bacterial meningitis treatment. This pre-pre-analytical error could have cost this patient their life had the laboratory not realized the wrong test was ordered.
Can you identify where the failure originated, or was there more than one locus? What are the factors at various levels in the system that may have contributed to the failure(s) you have identified? I will share my ideas for comparison.
The Points at which Failures Occurred
The LIS has ambiguous test names; “CRYPTO” could refer to Cryptosporidium or Cryptococcus. The specimen type on the label would be the only immediate information that would dictate to a trained and knowledgeable professional which test was to be performed. Otherwise, that information would need to be consulted from the computer’s LIS or medical record.
Including a stool sample before any orders were placed on it is not exactly part of the typical “rainbow draw” of tubes enjoyed by many. I matched the collected specimen to the ordered test, but what would have happened if no stool was in the laboratory? We would have probably called to inquire on its collection status, as it remained on the pending list some time later. If, however, the ED was truly expecting a Cryptococcus result, they may have called the lab before that point. Had a stool not been pre-collected, I am guessing somebody would have been calling somebody for a status update.
The laboratory does not see a “chief complaint” on the orders. Data is blindly collected without opportunity for the medical laboratory professional to correlate testing or results with the reason for ordering. This information is only found when entering the medical record with “reasonable suspicion” or “necessity” and is otherwise generally frowned upon for typical patient testing.
The wrong test was ordered. The provider ordered a stool test that detects the presence of an intestinal protozoan on a patient with signs and symptoms of meningitis. What testing information is available to the provider in the EMR when they place an order; sample requirements, testing purpose, possible result interpretations, suggested testing given signs/symptoms? The person entering the order may have had a faulty memory on organism names or simply clicked the wrong button.
Levels of Contributing Factors
- Individual provider—The provider may have mixed up the test names or incorrectly selected the wrong one.
- Process—The ordering process may not occur directly by the provider, and other team members may be involved in handling the order. The more steps an order passes through, the more opportunity for introduction of error.
- Patient/family—Not likely applicable. Failure was not related to patient noncompliance on exam or history.
- Team communication—The provider may have been misunderstood by an ED technician or nurse who actually placed the order for the provider. Ironically, it is also this same misunderstanding factor within the laboratory team that caught this mistake.
- Training and education—The provider/nurses may not have known there were similarly named organisms, or they may not have known the difference in how they are to be ordered. Again, it is also this same factor within the laboratory’s expertise on specimen and presentation that caught this mistake.
- Information technology—The ordering process within the LIS may have contained confusing terms. The LIS/EMR software may not have had confirmatory processes for orders placed.
- Leadership—There may not be a person serving as part of a check-system that verifies orders are correctly placed. The repercussions for errors are not immediate.
- Institutional environment—Were ED technicians/nurses so pressed for time that they overlooked the sample requirements and did not realize that the wrong order was made? Or did they recognize that this seemingly minor detail is truly significant and worth updating? Was the current morale impactful?
Critical thinking exercises like this promote a culture of patient safety and demonstrate the need for interdisciplinary teamwork and empathy. Reflect on these points next time you find yourself filling out an incident report … again.
- Laposata M, Dighe A. “Pre-pre” and “post-post” analytical error: high-incidence patient safety hazards involving the clinical laboratory. Clin Chem Lab Med. 2007;45(6):712-9. doi:10.1515/CCLM.2007.173
Sarah Bergbower is Assistant Professor of Life Sciences at IECC Olney Central College in Olney, Illinois.