Research issues in the evaluation of cognitive impairment in intensive care unit survivors

Abstract

Neuropsychological assessment has been utilized extensively in the research of cognitive outcomes associated with medical illnesses, such as HIV, and post-surgical procedures, such as coronary artery bypass graft. However, few investigations of intensive care unit (ICU) survivors have examined cognitive function as a clinical outcome. Significant clinical questions exist regarding the impact of critical illness on long-term cognitive function. Many of these questions can be systematically evaluated through the use of standardized neuropsychological assessment instruments within the context of well designed, prospective research trials. This review will provide information for clinical researchers interested in the study of neuropsychological outcomes in intensive care unit survivors ( a comparison article in this issue will address clinical issues related to cognitive functioning).

Behavioral deficits in sepsis-surviving rats induced by cecal ligation and perforation

“…Previous reports involving intensive care unit survivors demonstrated cognitive impairment at discharge from the hospital (9)(10)(11)(12)(13)(14)(15)(16)(17). In long-term follow-up studies most patients showed improvement in overall cognitive function; however, some cognitive skills, such as memory, were not completely recovered (9,13,14).…”

“…Recently, several studies have demonstrated that critical care survivors present long-term cognitive impairment, including alterations in memory, attention, concentration, and/or global loss of cognitive function (9)(10)(11)(12)(13)(14)(15)(16)(17). However, the neurobiological mechanisms involved in this cognitive impairment remain unclear.…”

Septic encephalopathy: does inflammation drive the brain crazy?

“…13 Likewise, survivors from critical care, including septic patients, have well-documented persistent neurocognitive deficits and develop psychiatric disorders. [14][15][16][17][18][19][20][21][22][23] The interaction between sepsis and the brain is an opportunity to study how systemic inflammation affects brain function. Most studies about the mechanisms of SE have used animals or cell cultures, and improved our understanding of how the CNS is affected by endotoxins and cytokines, but whether this is related to clinical SE remains unclear.…”

Understanding terminology of delirium and long-term cognitive impairment in critically ill patients

“…31 To date, there is still a lack of consensus on how to define LTCI-CI especially in comparison to other forms of cognitive impairments, though broad agreement exists that a uniform definition would be helpful. 60 Patients have been tested 25 with neuropsychological batteries, which assess different cognitive domains: mental status, psychomotor speed, verbal fluency, working memory, verbal memory, visual memory and visuo-construction. Though definitions vary, they have tended to be quite restrictive (e.g., difficult to reach), as using such definitions ensure that subjects defined as 'impaired' are truly impaired and not false positives.…”