(Failing to) Identify Severe Sepsis at Triage

This is the holy grail of predictive health informatics in Emergency Medicine – instant identification of serious morbidity, with the theoretical expectation of outcomes improvement due to early intervention.

And, more than almost any condition, accurate early identification of severe sepsis remains elusive.

This is an observational evaluation of the “Australian Triage Scale” in combination with infectious keywords as a tool to identify and manage patients with severe sepsis.  Patients were enrolled at presentation to the Emergency Department, and ultimately followed from triage through their ICU stay – where a clinical diagnosis of severe sepsis was used as the gold standard for outcomes. However, of the 995 patients triaged through the Emergency Department and ultimately diagnosed with severe sepsis, only 534 were identified at triage.  The authors present various diagnostic characteristics for each level of the ATS with regards to acuity, and the AUCs for sensitivity and specificity range from 0.457 to .567 (where 0.5 is basically a coin-flip).  So, the authors’ presented rule-based mechanism is nearly as likely to be incorrect as correct.  I’m not exactly certain how they came to the conclusion “the ATS and its categories is a sensitive and moderately accurate and valid tool”, but I tend to disagree.

These data are consistent with our a priori expectation for these sorts of tools.  The patients who trigger such rules are generally so obviously severe sepsis such rule-based notifications occur after clinician identification, and are simply redundant and alarm fatigue.  Conversely, patients with severe sepsis going undiagnosed upon initial presentation do so because of their atypical nature – and thus tend to fall outside rigid, rule-based constructs.  E.g., computers are not physicians … yet.

“Identification of the severe sepsis patient at triage: a prospective analysis of the Australasian Triage Scale”
http://www.ncbi.nlm.nih.gov/pubmed/25504659