Near-infrared spectroscopy in the assessment of suspected sepsis in the emergency department.

Background And Aims: The conventional approach to sepsis resuscitation involves early interventions targeting global oxygenation and macro-haemodynamic variables such as central venous and systemic arterial pressures. There is increasing recognition of the importance of microcirculatory changes in shock states, including sepsis, and the relationship of these to outcome. Near-infrared spectroscopy (NIRS) is a recently developed non-invasive technology that measures tissue oxygen saturations (StO2), which may be an indirect measure of the adequacy of the microcirculation. StO2 measurements, therefore, have the potential to identify patients who are at risk of progressing to organ dysfunction and could be used to guide resuscitation. This article reviews the current state of knowledge of NIRS in the setting of sepsis, examining its application, validity and prognostic value.

Methods: A search of the relevant literature was performed using Medline, Embase and Cochrane databases, and a qualitative analysis was undertaken.

Results: A limited number of observational studies, mostly conducted among patients with severe sepsis, have shown that NIRS may correlate with severity of illness but demonstrate a variable relationship between StO2 and outcome.

Conclusions: Outstanding questions still remain as to whether NIRS can help to risk-stratify patients with suspected sepsis in the emergency department and the utility of StO2 as a resuscitation target.