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

Published:March 09, 2017DOI:



      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 (>17 years) 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.


      Sto2 (soft tissue oxygen saturation), NIRS (near-infrared spectroscopy), MODS (multi-organ dysfunction syndrome), ESI (Emergency Severity Index), CI (confidence interval)


      To read this article in full you will need to make a payment
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The American Journal of Emergency Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Ward K.R.
        • Ivatury R.R.
        • Barbee R.W.
        • Terner J.
        • Pittman R.
        • Filho I.P.
        • et al.
        Near infrared spectroscopy for evaluation of the trauma patient: a technology review.
        Resuscitation. 2006; 68: 27-44
        • Duret J.
        • Pottecher J.
        • Bouzat P.
        • Brun J.
        • Harrois A.
        • Payen J.F.
        • et al.
        Skeletal muscle oxygenation in severe trauma patients during haemorrhagic shock resuscitation.
        Crit Care. 2015; 19: 141
        • Beekley A.C.
        • Martin M.J.
        • Nelson T.
        • Grathwohl K.W.
        • Griffith M.
        • Beilman G.
        • et al.
        Continuous noninvasive tissue oximetry in the early evaluation of the combat casualty: a prospective study.
        J Trauma. 2010; 69: S14-S25
        • Nicks B.A.
        • Campons K.M.
        • Bozeman W.P.
        Association of low non-invasive near-infrared spectroscopic measurements during initial trauma resuscitation with future development of multiple organ dysfunction.
        World J Emerg Med. 2015; 6: 105-110
        • Carlile C.
        • Wade C.E.
        • Baraniuk M.S.
        • Holcomb J.B.
        • Moore L.J.
        Evaluation of sto2 tissue perfusion monitoring as a tool to predict the need for lifesaving interventions in trauma patients.
        Am J Surg. 2015; 210 (discussion 5): 1070-1075
        • Khasawneh M.A.
        • Zielinski M.D.
        • Jenkins D.H.
        • Zietlow S.P.
        • Schiller H.J.
        • Rivera M.
        Low tissue oxygen saturation is associated with requirements for transfusion in the rural trauma population.
        World J Surg. 2014; 38: 1892-1897
        • Cohn S.M.
        • Nathens A.B.
        • Moore F.A.
        • Rhee P.
        • Puyana J.C.
        • Moore E.E.
        • et al.
        Tissue oxygen saturation predicts the development of organ dysfunction during traumatic shock resuscitation.
        J Trauma. 2007; 62 (discussion-5): 44-54
        • Neto A.S.
        • Pereira V.G.
        • Manetta J.A.
        • Esposito D.C.
        • Schultz M.J.
        Association between static and dynamic thenar near-infrared spectroscopy and mortality in patients with sepsis: a systematic review and meta-analysis.
        J Trauma Acute Care Surg. 2014; 76: 226-233
        • Vorwerk C.
        • Coats T.J.
        The prognostic value of tissue oxygen saturation in emergency department patients with severe sepsis or septic shock.
        Emerg Med J. 2012; 29: 699-703
        • Fernandes C.M.
        • Tanabe P.
        • Gilboy N.
        • Johnson L.A.
        • McNair R.S.
        • Rosenau A.M.
        • et al.
        Five-level triage: a report from the acep/ena five-level triage task force.
        J Emerg Nurs. 2005; 31 (quiz 118): 39-50
        • Wuerz R.C.
        • Milne L.W.
        • Eitel D.R.
        • Travers D.
        • Gilboy N.
        Reliability and validity of a new five-level triage instrument.
        Acad Emerg Med. 2000; 7: 236-242
        • Tanabe P.
        • Gimbel R.
        • Yarnold P.R.
        • Kyriacou D.N.
        • Adams J.G.
        Reliability and validity of scores on the emergency severity index version 3.
        Acad Emerg Med. 2004; 11: 59-65
        • Bazerbashi H.
        • Merriman K.W.
        • Toale K.M.
        • Chaftari P.
        • Cruz Carreras M.T.
        • Henderson J.D.
        • et al.
        Low tissue oxygen saturation at emergency center triage is predictive of intensive care unit admission.
        J Crit Care. 2014; 29: 775-779
        • von Elm E.A.D.
        • Egger M.
        • Pocock S.J.
        • Gøtzsche P.C.
        • Vandenbroucke J.P.
        • et al.
        The strengthening the reporting of observational studies in epidemiology (strobe) statement: guidelines for reporting observational studies.
        PLoS Med. 2007; 4e296
        • Gilboy Tanabe
        • Travers Rosenau
        Emergency severity index (esi): a triage tool for emergency department care, version 4.
        in: Implementation handbook 2012 edition. Agency for Healthcare Research and Quality, Rockville, MD2011 (Ahrq publication no. 12-0014)
        • Hutchinson Technology Inc.
        Inspectra sto2 spot check, model 300.
        2012: 1-4
        • Hutchinson Technology Inc.
        Inspectra sto2 spot check system, 510(k) summary, k103613.
        • Crookes B.A.
        • Cohn S.M.
        • Bloch S.
        • Amortegui J.
        • Manning R.
        • Li P.
        • et al.
        Can near-infrared spectroscopy identify the severity of shock in trauma patients?.
        J Trauma. 2005; 58 (discussion 13-6): 806-813
        • Scheeren T.W.
        • Schober P.
        • Schwarte L.A.
        Monitoring tissue oxygenation by near infrared spectroscopy (nirs): background and current applications.
        J Clin Monit Comput. 2012; 26: 279-287
        • Pitts S.R.
        • Niska R.W.
        • Xu J.
        • Burt C.W.
        National hospital ambulatory medical care survey: 2006 emergency department summary.
        Natl Health Stat Rep. 2008; 7: 1-38
        • Efron B.
        Better bootstrap confidence intervals.
        J Am Stat Assoc. 1987; 82: 171-185
        • Hadley W.
        The split-apply-combine strategy for data analysis.
        J Stat Softw. 2011; 40: 1-29
        • Davison A.
        • Padoan S.
        • Ribatet M.
        Statistical modeling of spatial extremes.
        Stat Sci. 2012; : 161-186
        • R Core Team
        R: a language and environment for statistical computing.
        R Foundation for Statistical Computing, Vienna, Austria2016
        • Iyegha U.P.
        • Conway T.
        • Pokorney K.
        • Mulier K.E.
        • Nelson T.R.
        • Beilman G.J.
        Low sto2 measurements in surgical intensive care unit patients is associated with poor outcomes.
        J Trauma Acute Care Surg. 2014; 76: 809-816
        • Goerlich C.E.
        • Wade C.E.
        • McCarthy J.J.
        • Holcomb J.B.
        • Moore L.J.
        Validation of sepsis screening tool using sto2 in emergency department patients.
        J Surg Res. 2014; 190: 270-275
        • Goulet H.
        • Andre S.
        • Sahakian G.D.
        • Freund Y.
        • Khelifi G.
        • Claessens Y.E.
        • et al.
        Accuracy of oxygen tissue saturation values in assessing severity in patients with sepsis admitted to emergency departments.
        Eur J Emerg Med. 2014; 21: 266-271
        • Dean N.C.
        • Jones J.P.
        • Aronsky D.
        • Brown S.
        • Vines C.G.
        • Jones B.E.
        • et al.
        Hospital admission decision for patients with community-acquired pneumonia: variability among physicians in an emergency department.
        Ann Emerg Med. 2012; 59: 35-41
        • Labarere J.
        • Stone R.A.
        • Obrosky D.S.
        • Yealy D.M.
        • Meehan T.P.
        • Fine J.M.
        • et al.
        Comparison of outcomes for low-risk outpatients and inpatients with pneumonia: a propensity-adjusted analysis.
        Chest. 2007; 131: 480-488