The StO2 non-invasive tissue hypoperfusion monitor as a screening tool for early sepsis detection in the emergency department

Georgia

Background: Early Recognition of patients with sepsis induced tissue hypoperfusion (SITH) Remains a significant clinical challenge. Non--‐invasive Tissue oxygenation saturation (StO2) Monitors have been developed to provide rapid, low--‐cost, and non--‐invasive bedside assessments of tissue oxygen extraction; they have not been well validated as an initial screening tool for sepsis in the ED. Objectives: To Assess the efficacy of initial bedside StO2 Readings in the early identification of patients with SITH And to compare StO2 Readings with lactate levels. Methods: IRB approved, prospective, observational pilot study of a convenience sample of ED Patients presenting with a sepsis continuum diagnosis. Setting: Urban Tertiary care center with 90k visits/yr. Inclusion criteria: Suspicion Of new infection plus 2 SIRS criteria. Exclusion criteria: <18 Or no suspicion of infection. Study procedures:>Demographics, co--‐morbidities, clinical data, treatment, disposition, and mortality were collected. A Portable In--‐Spectra ‘Spot Check’ StO2 Monitor was used totake a StO2 Reading at the thenar eminence; a second reading was taken three hours later. All Investigators were trained with the device to record data with a high degree of accuracy and reliability. Abnormal StO2 Was defined as <80% or>91%. The Study was observational and there were no clinical interventions. Descriptive Statistics were employed and Sensitivity/Specificity, Likelihood ratios, andNPV/PPV Were calculated with 95% Confidence intervals (in parenthesis) where appropriate. Results: 79 Patients were enrolled into the study. Mean Age 63 (range 21--‐96). 61 Were admitted to the hospital, 5 To ICU (100% With St02<74%). 3 Mortalities (100% With St02<72%). 75% (9/12) Of patients with an ED Lactate >2.3 Had an abnormal St02. 80% (4/5) For lactate >3, And 100%(3/3) For Lactate >4. For Any initial SITH (MAP<65 Or Lactate>2.3): Sensitivity: 92% (77.5--‐98.2), Specificity: 82.2% (67.9--‐92), +LR: 5.2 (2.7--‐9.7), --‐LR: 0.1 (0.03--‐0.3), PPV: 80.5% (65.1--‐91.2), NPV: 92.5% (80--‐98.3). Conclusions: StO2 May be a useful, rapid, low--‐cost, and non--‐invasive bedside screening tool for SITH In the ED, Particularly for severely ill patients. Further Studies are needed to determine StO2’s Ability to predict mortality and assess response to therapy.