The following post was written several years ago. Although more recent developments have changed the field of clinical laboratory science since the original posting, the information contained was deemed to be of historical interest.

Since the introduction of critical results reporting by Lundberg over 30 years ago certain issues have remained controversial to this day, at least at our institution, e.g., is it critical or is it simply medically important information? And, if it’s medically important is the laboratory obligated to communicate directly with the physician in a timely manner, e.g., a telephone call.

As with most controversies productive discussion is often aided by making presuppositions explicit. Our institutional policy, appropriately in my opinion, adopted Lundberg’s original definition of a critical result: “… one that represents a pathophysiological state at such variance with normal as to be life threatening unless something is done promptly and for which corrective action could be undertaken.” Without the criteria provided by this definition institutional lists of critical value can end up being lengthy lists of tests that will likely include medically important as well as critical results. Co-mingling the two types of results can consume considerable laboratory resources to meet the strict standards of timeliness and documentation required for critical results, and has the potential to ultimately desensitize medical staff to those telephone calls that deal with truly life-threatening results demanding immediate attention.

What has been overlooked by some is that Lundberg published a subsequent letter proposing the additional distinction of what he called “vital laboratory values”: “… values that represent a pathophysiological state at such variance with normal as to be life threatening and for which corrective action can be taken but for which rapid action is not crucial.” Examples of test results that fit this definition readily come to mind and while not extensive the list of tests included under this category would be much more extensive than those fitting the definition of critical results. Interestingly, the College of American Pathologists (CAP) General Checklist specifies that an accredited laboratory must have a policy for the timely reporting of what Lundberg referred to as vital results but it only encompasses results relevant to the diagnosis of particular infectious diseases (e.g., human immunodeficiency virus, tuberculosis; CAP GEN.41316); other test results that may properly fit into this same category of medical relevance and urgency are not included. Perhaps a broader definition in the CAP accreditation standards would be appropriate.

Why make a fuss over the distinction? First, much stricter regulatory and medical-legal criteria and scrutiny apply to test results categorized as “critical results”, e.g., who may receive the information, the extent of documentation required and standards of performance (one hour or less depending upon institutional policy) thus requiring more intensive use of laboratory resources to meet the demands invoked by the classification as is appropriate. Whereas test results considered vital can be communicated using less demanding methods, including asynchronous electronic means that are not readily applied to communication of critical results. Secondly, clear definition and delineation of what test results will be treated as critical versus vital is necessary for medical staff education. Likely laboratory professionals have received irate calls from physicians wanting to know why the laboratory didn’t telephone them with the results of an abnormal test, e.g., an ALT of 300 IU/L in an outpatient.

It is difficult to be unsympathetic with physician demands for more direct communication regarding abnormal laboratory results in light of the sheer volume of data they must track, and considering that while the electronic record provides enhanced information management in many regards the loss of clear context and visibility of information can actually make it more difficult to be aware of laboratory results particularly when the test results are not available within a day or so of the date ordered. Nevertheless, to expand the definition of critical results to meet physician expectations risks the integrity of a system that is meant to provide timely and accurate reporting to a responsible party in circumstances that may be life threatening. As laboratory professionals I believe it is incumbent on us to work collaboratively with our physician colleagues to strictly define critical results for the patient population served and to monitor and maintain high performance standards for communication of said critical results.

Is there an exception to the requirement to directly communicate critical results when the result(s) is noted again in a relatively short time period? Are technological solutions for asynchronous communication sufficient in these situations? What do you think? Call centers, do they work for communicating critical results and if so what are the elements that assure success? Does your critical value policy and procedure specify and escalation pathway? Stay tuned for more discussion on this subject.