Title

Establishing an Evidence Base for Critical Laboratory Value Thresholds

Publication Date

2014

Journal Title

Am J Clin Pathol

Abstract

Objectives: Critical values denote laboratory test results indicating a life-threatening situation. The outcomes of this premise have not been rigorously evaluated. Methods: Five years of inpatient admissions were examined for critical or "near-critical" results (total admissions = 165,066; total test results = 872,503). In-hospital mortality was examined as a fitnction of time and degree of test result abnormality. Results: Some critical value thresholds appropriately identified patients at risk for death (eg, elevated potassium). Other thresholds were too conservative (elevated hematocrit, hemoglobin) or not conservative enough (elevated lactate). Mortality risk for most critical values was time dependent, but some critical values showed no temporal effect on mortality (elevated activated partial thromboplastin time [APTT], international normalized ratio [INR], and glucose). Following an initial critical result, further worsening was associated with increased mortality. Prior hospital admission within 30 days was a predictor of lower mortality for some (elevated APTT, INR, potassium, and sodium; low glucose, hem atocrit, hemoglobin, and potassium) but not other critical values (elevated lactate, glucose, hematocrit, and hemoglobin; low sodium). Conclusions: Only a subset of laboratory critical value thresholds was optimally chosen for increased risk of in-hospital mortality, with a time urgency for most but not all critical values. For many tests, a prior hospital admission imparted a decreased risk of in-hospital death.

Volume Number

142

Issue Number

5

Pages

617-628

Document Type

Article

EPub Date

2014/10/17

Status

Faculty; Northwell Resident

Facility

School of Medicine; Northwell Health

Primary Department

Pathology and Laboratory Medicine

PMID

25319976

DOI

10.1309/ajcpdi0fyz4unweq