Thermal challenge of the microcirculation in patients after cardiac surgery

Microcirculatory alterations have been correlated with poorer outcomes in different populations of critically ill patients. A controlled increase in the local skin temperature (thermal challenge) induces vasodilation, which may represent a measure of microcirculation recruitability and can be easily evaluated non-invasively using skin laser Doppler (SLD) (1). We previously demonstrated lower SLD values during thermal challenge in patients with circulatory shock, particularly in non-survivors (2).