Autonomic dysfunction in critically ill patients

Abstract

Autonomic nervous system is a very important system to study, because, it’s dysfunction is integrated in patho-physiology, clinical picture, complications and prognosis of many diseases. To hit this target, we should identify the anatomy and physiology of each component of this system including reflex arc ( afferent, efferent and center ) and neurotransmitters of the two limbs of this system ( sympathetic & parasympathetic pathway ). Autonomic nervous system is evaluated for critically ill patients in ICU using different markers; including : HRV ( the most common marker used in ICUs ), skin wrinkling test, baroreflex sensitivity test, valsalva maneuver andorthostatics. By testing the autonomic nervous system in critically ill patients, we can predict the prognosis and outcome and may help in early diagnosis of some critical illnesses as sepsis. By testing ANS we can discover the autonomic dysfunctions of some diseases which are common to be present as a co- morbidity in critically ill patients; as diabetes mellitus.