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Logo of nihpaAbout Author manuscriptsSubmit a manuscriptHHS Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
MLO Med Lab Obs. Author manuscript; available in PMC 2010 May 7.
Published in final edited form as:
MLO Med Lab Obs. 2009 March; 41(3): 18–19.
PMCID: PMC2865897

Critical values launch interpretive lab medicine and clinical pathology

Carren Bersch, MLO editor and Kristin N. Hale, BS, BA

MLO: George D. Lundberg, MD, has been credited with “inventing” — or, perhaps, more accurately “first implementing” — the system of critical-value reporting in 1970. He recently said that “… the critical value can serve as a nidus or a launching part for the whole issue of interpretive laboratory medicine, interpretive clinical pathology, because all of us in pathology know that large numbers of clinicians haven’t the foggiest notion how to properly order laboratory tests or how to interpret them correctly.“ With the advent of lab automation, which is part of the solution to losing scores of retiring “seasoned” MTs and MLTs who have the experiential knowledge that newcomers do not, will the concept of critical values and/or the process of establishing critical values change in any substantial way(s) — how and why?

D. Robert Dufour, MD: I believe that the idea of “critical values” will persist, even with increasing automation. Even with autoverification, there is a requirement to develop rules for results that require review by a laboratory scientist before release to the physician. Strong evidence suggests that the busy physician often ignores unexpectedly abnormal results, so that notification of any life-threatening values will remain important for patient safety. The mechanism for determining critical values has been, for the most part, a decision made at individual hospitals. I believe that a “consensus” approach, such as has been developed in the state of Massachusetts, will become more widely accepted as a way to determine critical values.

Gerald J. Kost, MD, PhD: The concept of critical values, process of establishing them, and methods of closing the loop clinically are evolving, and we hope for the better. When reporting a critical value, as regulated by the The Joint Commission (TJC) and its new national patient-safety goals, the laboratorian first must verify the result and then notify the nurse or doctor of the patient’s critical value. The nurse or doctor receiving the information is required to read back the critical value.1 Recently, TJC requires documented confirmation that the patient’s physician has actually received the critical-value information, which will be entered into the patient’s electronic medical record.2 Furthermore, when the nurse receives notification, she is given only about one hour to contact the doctor and confirm closure in the patient’s electronic medical record.2 This process functions to ensure that the patient’s critical value is verified efficiently and that the essential information is disseminated to the proper medical personnel. The endpoint, of course, is to treat the patient promptly and as clinically indicated, thereby improving outcomes. In fact, this was the subject of a cover story I wrote for MLO in March 1993 entitled “Using critical limits to improve patient outcome.”

A medical technologist must verify the result, even if the lab is automated. The effectiveness of coupling a computerized notification system was evaluated in a recent study conducted by Dr. Piva and colleagues at The Padua Hospital in Italy.3 Specifically, the communication process after the critical value was verified by a lab technician was altered to a computer-based dissemination model, which sought to eliminate errors associated with the call back, that is, the read-back system rein-forced by TJC and the College of American Physicians (CAP).1,3,4 Results indicated that the computerized process reduced notification time and eliminated errors associated with phone notification and misinterpretation of critical values.3 Thus, the coupling of laboratory process to verify critical values with improved dissemination methods to notify medical personnel of the critical values has the potential to positively impact and refine the current model of critical-value-reporting dissemination by reducing errors, improving notification time, and enhancing reliability. It also allows the laboratory-quality department to quantitatively monitor endpoint performance and prove high quality during accreditation inspections.

MLO: In what ways do you perceive handling critical-value reporting might change in the future? Will the requirement for follow-up remain on the “shoulders” of the lab, or do you think that clinicians will be more mindful of asking for specific information regarding patients? Will electronic medical records change the method by which critical values are reported? Are there any other changes occurring within tthe lab that might usher in more regulation of this area of performance, such as “globalization”?

Dufour: One way that reporting may change is in developing different “priorities” of critical values. For example, the state of Massachusetts established different levels of critical values (red, orange, and yellow) that have different time thresholds for reporting. The Massachusetts system also eliminated reporting for repeat critical values for many tests. In our hospital, we adopted a similar approach several years ago, based on the Massachusetts model. We have seen a significant reduction in the number of calls made to clinicians as a result.

As far as how much of a change electronic medical records will make in the need to communicate critical values, I work in a system with a very advanced computerized medical-record system. Although the system can be set to make an “alert” for every critical (or abnormal) value, many physicians have turned off these alerts. Also, because the alerts go to the attending physician (who may not be the doctor who has ordered the test, or who may be on vacation), alerts may not be seen in a timely fashion even when the alerts are turned on. For this reason, we have not found a reduction in need to use critical-value notification, even when we have an electronic-alert system. I believe that, in the interests of patient safety, there will continue to be a need for communicating critical values in a timely fashion.

Kost: Fundamentally, the physician is responsible and must inquire on behalf of the patient. Litigation proves this point over and over. The laboratory, however, shares in the responsibility. The concept of critical values will continue to be important to the medical laboratory scientist, perhaps even more so in the age of automation. As regulated by TJC, verification and reporting of critical values relies on medical laboratory personnel1 even when testing is performed at the point of care. The method of dissemination can be refined and modified as new technologies become available, such as wireless telecommunication, which could even reach out directly to the patient.

Laboratory personnel can integrate technological advances into the dissemination process and decrease the critical-value notification time. A study conducted by Dr. Kuperman and colleagues found that an automatic alerting system for critical values facilitated rapid transmission of information and could be used to improve patient care.5 So, automation does not mean just mechanized testing. Instead, we can automate information as we move forward into the realm of cyberknowledge and cyberphysical computing, which represent current research pursuits for seamless healthcare with the National Science Foundation. Fast turnaround times for alerting medical personnel of critical values are important for prompt clinical evaluation and patient treatment. Remember, by definition, there should be the potential to treat the patient if the analyte appears on the critical values list. We are not talking about an academic exercise.

In the future, the handling of critical values should combine the entire team of laboratorians, medical assistants, nurses, doctors, informaticists, and cyberengineers cooperatively working together to bidirectionally relay information from the lab to the respective medical department, physician and patient for timely clinical action. The use of electronic medical records to report critical values is required by the TJC and now used during audits of timeliness (closing the reporting loop) in medical institutions.1,2 In addition, having this information up to date and readily available can aid doctors during urgent clinical evaluation and shorten the time to diagnosis and treat.5 National patient-safety goals set forth by the TJC (and CAP) provide guidelines that are followed for critical-values reporting, and these guidelines and regulations will continue to be improved upon and supplemented with the development and integration of new cybertechnologies like automatic alerting systems and electronic medical records.1,2,4,5

MLO: While critical-value notification procedures are essential for clinical labs and are required by CAP’s lab-accreditation program and TJC standards, are there still any variances among labs in certain areas of which you might be aware that should be standardized across the board? Or over these past three decades, have most of the “kinks” been “ironed out” of critical-values practices?

Kost: Wow, kinks and maybe curves, too! We wish the road were smooth and straight, but it is not.

Dufour: Critical-value notification remains a significant issue for laboratories. Data from CAP Q-probe studies continues to show that, particularly for outpatients, there are often significant delays in communicating critical-value results. I think, again, the approach taken in Massachusetts, of establishing “back-up” physicians to take critical values is a significant part of the solution to providing timely patient care. We have had such a back-up system in our institution for over 20 years, with variable success (generally, it works well for outpatients in getting the result to a physician, but there are often problems in reaching the patient with the critical result).

Kost: The guidelines and regulations set forth by TJC and CAP provide the foundation for critical-value reporting practices. Standards continue to evolve, however, and in some settings are inadequate, such as for neonate and pediatric patients.4,6 A national survey I conducted sought to summarize the critical limits utilized for newborns and children, which for these vulnerable populations no published tables or lists by accreditation agencies were available at the time.6 Results indicated the need to standardize and distinguish critical tests for acute treatment, define quantitative critical values relative to clinical diagnosis, and refine critical tests based on various hospital units and age groups.6 Furthermore, the results encouraged making the concept of critical limits and values straightforward to facilitate rapid turnaround reporting times and prompt clinical evaluation.6 We must close the information loop outside the hospital too. Information control and monitoring in the outpatient setting are particularly challenging; we only have partial solutions. Again, litigation proves the point. Each year, there are instances where the ball is dropped — a critical result missed — and sometimes, the patient suffers.

While significant progress has been made in the reporting of critical values, in part due to the standardization of critical-value regulations by TJC and CAP, the development of new and efficient technologies, particularly for outpatients, can only enhance the system currently in place.1,4 In a study conducted by Dr. Dighe and colleagues, the reporting of critical values was evaluated at a large medical center to assess the effectiveness of the current practice.7 Results suggested that using phone calls as the main dissemination method for reporting critical values, in addition to an increasing workload for laboratory technicians, is costly.7 A quick turnaround time for reporting critical values is necessary in order to ensure a level of patient care and treatment consistent with the standard of care nationwide. It was suggested that integrating new technologies into the current system would alleviate time delays in reporting critical values by the laboratory.7 Striving to better current critical-value reporting is a continual process that involves the entire continuum of care — hospital to home — and will undergo revisions and developments as technological advances and discoveries emerge.


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D. Robert Dufour, MD, FACP, FACB, is emeritus professor of Pathology, George Washington University; and medical center consultant, Hepatology and Laboratory Medicine at the VA Medical Center, Washington, DC.

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Gerald J. Kost, MD, PhD, directs the Point-of-Care Testing Center for Teaching and Research at the University of California-Davis, among other duties.


1. Joint Commission on the Accreditation of Healthcare Organizations. National patient safety goals hospital program, goal 2. [Accessed February 24, 2009]. Available at
2. Personal communication. Doug Wright. 2009 February 25;
3. Piva E, Sciacovelli L, Zaninotto M, Plebani M. Evaluation of effectiveness of computerized notification system for reporting critical values. Aw J Clin Pathol. 2009;131:432–441. [PubMed]
4. Accreditation and Laboratory Improvement. [Accessed February 24, 2009]. College of American Pathologists. Available at
5. Kuperman GJ, Teich JM, Tanasijevic MJ, et al. Improving response to critical laboratory results with automation: results of a randomized controlled trial. Journal of the Am Medical Informatics Association. 1999;6:512–522. [PMC free article] [PubMed]
6. Kost GJ. Critical limits for emergency clinical notification at United States children’s hospitals. Pediatrics. 1991;88:597–603. [PubMed]
7. Dighe AS, Rao A, Coakley AB, Lewandrowski KB. Analysis of laboratory critical value reporting at a large academic medical center. Am J Clin Pathol. 2006;125:758–764. [PubMed]