Soft tissue oxygen saturation to predict admission from the emergency department: A prospective observational study

We evaluated a soft tissue oxygen saturation (Sto2) measurement at triage for predicting admission to the hospital in adults presenting to the emergency department (ED) in addition to data routinely gathered at triage.

This was a prospective, observational, single center study of adults presenting to the ED for evaluation. Research assistants obtained thenar eminence Sto2 measurements on subjects in ED triage. ED providers not involved in the study then made all management and disposition decisions. We prospectively collected data on each subject's final ED disposition (admission versus discharge). We identified the optimal Sto2 cutoff value for predicting admission. We then used logistic regression modeling to describe the added predictive value of Sto2 beyond routinely collected triage data including Emergency Severity Index level, age, and vital signs.

We analyzed 2588 adult (>17years) subjects with 743 subjects (28.7%) admitted to the hospital. Sto2<76% was the optimal diagnostic cutoff for predicting admission. Of subjects with Sto2<76%, 158 of 384 (41.1%) underwent admission versus 585 of 2204 (26.5%) subjects with Sto2≥76. After controlling for age, vital signs, and ESI level in the logistic regression analysis, Sto2<76% had an odds ratio of 1.54 (95% confidence interval (CI), 1.19 to 1.98) for predicting admission.

Sto2 may provide additional prognostic data to routine triage assessment regarding the disposition for undifferentiated adult patients presenting to the ED.