Web-accessible critical limits and critical values for urgent clinician notification

To survey the World Wide Web for critical limits/critical values, assess changes in quantitative low/high thresholds since 1990-93, streamline urgent notification practices, and promote global accessibility.

We identified Web-posted lists of critical limits/values at university hospitals. We compared 2023 to 1990-93 archived notification thresholds.

We found critical notification lists for 26 university hospitals. Laboratory disciplines ranged widely (1-10). The median number of tests was 62 (range 21-116); several posted policies. The breadth of listings increased. Statistically significant differences in 2023 vs. 1990 critical limits were observed for blood gas (pO₂, pCO₂), chemistry (glucose, calcium, magnesium), and hematology (hemoglobin, platelets, PTT, WBC) tests, and for newborn glucose, potassium, pO₂, and hematocrit. Twenty hospitals listed ionized calcium critical limits, which have not changed. Fourteen listed troponin (6), troponin I (3), hs-TnI (3), or troponin T (2). Qualitative critical values expanded across disciplines, encompassing anatomic/surgical pathology. Bioterrorism agents were listed frequently, as were contagious pathogens, although only three hospitals listed COVID-19. Only one notification list detailed point-of-care tests. Two children's hospital lists were Web-accessible.

Urgent notifications should focus on life-threatening conditions. We recommend that hospital staff evaluate changes over the past three decades for clinical impact. Notification lists expanded, especially qualitative tests, suggesting that automation might improve efficiency. Sharing notification lists and policies on the Web will improve accessibility. If not dependent on the limited scope of secondary sources, artificial intelligence could enhance knowledge of urgent notification and critical care practices in the 21st Century.