Cognitive Dysfunctions Associated With Delirium in Critically-ill ARDS Patients

Cognitive Dysfunctions Associated With Delirium in Critically-ill ARDS Patients: Diagnostic and Prognostic Electrophysiological Signatures

Early cognitive assessment of critically-ill acute respiratory distress syndrome (ARDS) patients with delirium using a multidimensional electrophysiological evaluation battery (mEEG) to identify and characterize the neural correlates of cognitive dysfunctions associated with delirium (vigilance, attention, semantic and lexical processing, self-processing), and to develop a prognostic evaluation of neurocognitive and psychological disorders using an innovative non-behavioral approach.

Delirium is an altered mental status associated with specific manifestations such as reduced ability to direct, focus, maintain and shift attention (DSM V criteria). The vulnerability of critically-ill ARDS patients explains the high incidence of delirium (up to 80%) in this setting. Delirium is an independent predictor of post-traumatic stress disorder, long term cognitive decline and mortality. To reduce this medical and social burden, a more complete description of delirium is needed both in terms of cognitive impairments and long term neurological and neuropsychological impact. Actually, it could be argued that the current exclusive behavioral assessment of these patients is insufficient in terms of diagnosis and prognostic assessment. In recent years, the study of consciousness has made major progress thanks to the use of innovative electrophysiological exploration methods. This work has notably allowed the development of new non-behavioral tools for the exploration of brain function in brain damaged patients in response to complex auditory stimulations (multidimensional electrophysiological battery, mEEG). In this context, the investigator team has recently demonstrated alterations in cognitive functions related to language- and self-processing in ARDS patients with severe acute respiratory syndrome (SARS)-CoV2 infection. These electrophysiological cognitive alterations were particularly marked in COVID-19 patients with delirium. Further studies are needed to disentangle the cognitive impact specifically related to delirium from that related to a severe form of COVID-19. The primary objective of this study is to identify diagnostic electrophysiological signatures of cognitive dysfunctions associated with the acute phase of delirium in critically-ill ARDS patients using a multidimensional electrophysiological assessment (mEEG) recording at rest and during auditory stimulation (first visit, V1). Secondary objectives are to characterize the impact of intensive care unit (ICU)-related delirium on neurocognitive and psychological dysfunctions observed at 6 months (second visit, V2), in order to explore the prognostic predictive value of electrophysiological data acquired during the acute phase of delirium.

Inclusion Criteria:

• Patients admitted to the intensive care unit with ARDS (according to Berlin criteria)
• Delirium (according to Confusion Assessment Method (CAM)-ICU criteria)
• Membership of a social security scheme
• Signed consent of the referring person
• Discontinuation of any sedative agent for ≥ 72 hours

Exclusion Criteria:

• Pre-existing psychotic disorders
• Pre-existing cognitive deficits (short Informant Questionnaire on Cognitive Decline in the Elderly (short IQCODE) ≥ 3,4)
• Recent ICU admission (> 5 days of ICU hospitalization within 6 months prior to current ICU admission)
• Patients whose delirium cannot be reliably assessed due to blindness, deafness or inability to speak French
• Patients whose life expectancy is unlikely to exceed 24 hours
• Pregnant ans breastfeeding women
• Patients under court protection
• Patients who have already participated in the study