Ever since George Lundberg introduced the concept of critical laboratory values in the 1970s, medical technologists have considered it their duty to expeditiously validate and report these values by calling the respective patient units and reading the numbers to the caretaker. Critical value reporting became official when it was incorporated into the CLIA of 1988, and the CLIA recommendations were widely adopted by laboratory accrediting agencies, such as The Joint Commission and the College of American Pathologists (CAP). Subsequently, the requirement of having the caregiver write down and read back the critical value information (so-called read-back) was introduced as a means of improving patient safety. Recently, some laboratories have questioned current practices and introduced changes to increase speed and reliability of reporting. Two examples are listed, both of which raise questions.
One group of investigators argued that modern analyzers are more precise than earlier instruments and that repeating critical values would not increase accuracy (Chima HS, Ramarajan V, Bhansali D: Is it necessary to repeat critical values in the laboratory? Today’s technology may have the answer. Lab Medicine 2009; 40:453-7). Using glucose, potassium, activated partial thromboplastin time, and platelets they showed that repeat values might be slightly different statistically but not clinically significant. They discontinued repeat testing of crisis values and observed no reportable patient care issues during a six-month follow-up period.
Should we stop repeating critical values?
In our laboratory, we have not gone as far as eliminating repeat testing altogether, but for selected tests (potassium, glucose) we have instituted early notification of crisis values to a specific location, namely the emergency department. This means that a crisis value (e.g., K = 7.5 mEq/L) is reported and then repeated.
We replaced the traditional verbal reporting with an electronic reporting system that was developed by a multi-disciplinary team of laboratorians, clinicians, and information technology experts (Parl FF, O’Leary MF, Kaiser AB, Paulett JM, Statnikova K, Shultz EK: Implementation of a closed-loop reporting system for critical values and clinical communication in compliance with goals of the Joint Commission on the Accreditation of Healthcare Organizations. Clin Chem 2010; 56:417-423).
Does electronic reporting improve patient care and is the implementation effort worthwhile?
Our electronic system reports critical values via the laboratory and hospital information systems to alpha-numeric pagers of clinicians and ensures fail safe notification, instant documentation, automatic tracking, escalation and reporting of critical value alerts. A method for automated acknowledgment of message receipt was incorporated into the system design resulting in a median acknowledgment time <3 min by physicians. The system covers in-patients and eliminated over 10,000 phone calls per year previously made by medical technologists.