Delirium, cognitive dysfunction and posttraumatic stress disorder

In the critically ill patient, disease and the therapies we use impact on brain function. Simple tools are now available to recognise such problems. This review highlights neuropsychiatric and cognitive observations that have direct relevance to patient care and outcome.

Delirium is a common event, especially the hypoactive forms in the elderly. The recognition of significant cognitive dysfunction is worrying since it has profound implications for how we treat and manage patients within intensive care and beyond. The most important message is that the 'awake' intensive care unit patient is not necessarily free of significant brain dysfunction. There is also the added complication of psychological disturbances related to real or imagined delusional experiences underlying the importance of memory and recall. Longer-term implications, particularly debilitating conditions such as posttraumatic stress disorder, mean that there is a need for improved post-intensive care unit rehabilitation care.

Health professionals working with the critically ill must routinely include the assessment of brain cognitive function. While some of the consequences may be unavoidable, we need to reassess our sedation and care practices to ensure we are not confounding the problem. Practical options to improve outcome are being developed and emphasise that the recovery from critical illness is psychological as well as physical.