Tissue oxygen saturation for the risk stratification of septic patients

Peripheral tissue oxygen saturation (Sto2) has shown promise as an early indicator of tissue hypoperfusion and as a risk stratification tool in various forms of shock. The purpose of this study was to determine if Sto2 would predict admission to an intensive (ICU) or progressive care unit in patients with early signs of sepsis.

In this prospective observational study, a rapid response team measured Sto2 levels in patients screening positive for sepsis. Using a logistic regression model, the value of Sto2 as a predictor for ICU admission within 72 hours of the initial assessment was determined.

The 31 (47%) of 66 patients who required ICU admission within 72 hours of evaluation had a significantly lower Sto2 value (median, 78% vs 81%; P = .05). All patients with Sto2 less than 70% required ICU admission. A 1-point increase in Sto2 was associated with a 7% decrease in the odds of requiring ICU admission, and the area under the curve for Sto2 was 0.64 (0.51-0.77, P = .01).

Low Sto2 levels in patients screening positive for sepsis are associated with an increased risk of ICU admission, but their reliability as a predictor is rather low. An Sto2 below 70% might be an interesting cutoff value for further study.