Potential mechanisms and markers of critical illness-associated cognitive dysfunction

Purpose of review To review the current understanding of the potential mechanisms of critical illness-associated cognitive dysfunction and to provide insight into markers that could be used to evaluate the influence of specific mechanisms in individual patients. Recent findings Cognitive dysfunction is common in critically ill patients, not only during the acute illness but also long after it's resolution. Several pathophysiological mechanisms are thought to underlie critical illness-associated cognitive dysfunction, including neurotransmitter abnormalities and occult diffuse brain injury. Markers that could be used to evaluate the influence of specific mechanisms individual patients include serum anticholinergic activity, certain brain proteins, and tissue sodium concentration determination by way of high-reolution three-dimensional magnetic resonance imaging. Summary Although recent advances in this area are exciting, they are still too immature to influence patient care. Additional research is needed to provide a better understanding of the relative contribution of specific mechanisms to the development of critical illness-associated cognitive dysfunction and to determine whether these mechanisms might be amenable to treatment or prevention.