Examination of the autonomic nervous system in the ICU: a pilot study

The most widely used test for autonomic dysfunction in the ICU is the heart rate variability (HRV) test [1]. HRV is thought to be a very sensitive but less specific test [1]. Several other tests are available. For this pilot study we have investigated the ability of two tests, the skin wrinkle test (SWT), a test for postganglionic sympathetic function, and the cold face test (CFT), a reflex slowing heart rate after cold application to the forehead, to detect autonomic dysfunction in critically ill patients alongside the HRV.