Core-to-skin temperature gradient measured by thermography predicts day-8 mortality in septic shock: A prospective observational study

Abstract

Background: Septic shock is associated with altered peripheral perfusion. Core-to-skin temperature gradient depends on skin perfusion and microcirculatory function. We hypothesized that a high core-to-skin temperature gradient is correlated with mortality in septic shock.

Methods: We conducted a prospective observational study including 61 patients at the first 24 h of a septic shock in an intensive care unit. During the 24 first hours after norepinephrine administration, we collected clinical and circulatory characteristics, skin perfusion assessment (Capillary refill time (CRT), Mottling score) and we measured skin temperature with an infrared thermographic camera. We measured the Core-to-skin temperature gradient to evaluate if it is a predictor of day-8 mortality.

Results: Day-8 mortality was 16.3%. Core-to-index finger temperature gradient >7 °C was associated with day-8 mortality (OR = 18.0, [3.02-346.14], p = 0.002). This association was still significant after adjustment to the SOFA (Sequential Organ Failure Assessment) score. A model including a high SOFA score and a core-to index finger >7 °C was effective to predict day-8 mortality (c-statistic: 0.8735 [0.770-0.976]). Core-to-index finger temperature gradient was correlated with CRT, Mottling Score, and arterial lactate levels.

Conclusions: Core-to-index finger temperature gradient higher than 7 °C predicts day-8 mortality in septic shock and is correlated with other tissue perfusion markers.

Keywords: Peripheral perfusion; Sepsis; Septic shock; Skin temperature; Thermography.