Electroencephalography of mechanically ventilated patients at high risk of delirium

Abstract

Objective Neurophysiological exploration of ICU delirium is limited. Here, we examined EEG characteristics of medical‐surgical critically ill patients with new‐onset altered consciousness state at high risk for ICU delirium. Materials and methods Pre‐planned analysis of non‐neurological mechanically ventilated medical‐surgical ICU subjects, who underwent a prospective multicenter randomized, controlled EEG study (NCT03129438, April 2017–November 2018). EEG characteristics, according to the 2012 ACNS nomenclature, included background activity, rhythmic periodic patterns/epileptic activity, amplitude, frequency, stimulus‐induced discharges, triphasic waves, reactivity, and NREM sleep. We explored EEG findings in delirious versus non‐delirious patients, specifically focusing on the presence of burst‐suppression and rhythmic periodic patterns (ictal‐interictal continuum), and ictal activity. Results We analyzed 91 patients (median age, 66 years) who underwent EEG because of new‐onset altered consciousness state at a median 5 days from admission; 42 patients developed delirium (46%). Burst‐suppression (10 vs 0%, p = .02), rhythmic/periodic patterns (43% vs 22%, p = .03) and epileptiform activity (7 vs 0%, p = .05) were more frequent in delirious versus non‐delirious patients. The presence of at least one of these abnormal EEG findings (32/91 patients; 35%) was associated with a significant increase in the likelihood of delirium (42 vs 15%, p = .006). Cumulative dose of sedatives and analgesics, as well as all other EEG characteristics, did not differ significantly between the two groups. Conclusion In mechanically ventilated non‐neurological critically ill patients with new‐onset alteration of consciousness, EEG showing burst‐suppression, rhythmic or periodic patterns, or seizures/status epilepticus indicate an increased risk of ICU delirium.

Case of Persistent Post-ictal and Inter-ictal Delirium

“… 6 Another prospective multicenter randomized controlled study revealed a 7% increase in prevalence of delirium in mechanically-ventilated patients with observable seizures and status epilepticus on EEG. 11 Both findings suggested a significant contribution of seizures to the evolution of delirium. 6 , 11 In another study, nonconvulsive status epilepticus and interictal discharges were found in 12% and 30% of elderly delirium patients, respectively, irrespective of the etiologies.…”

“… 11 Both findings suggested a significant contribution of seizures to the evolution of delirium. 6 , 11 In another study, nonconvulsive status epilepticus and interictal discharges were found in 12% and 30% of elderly delirium patients, respectively, irrespective of the etiologies. 12 It can be theorized that the presence of an epileptic focus in the cortex promoted encephalopathy via widespread neuronal metabolism alteration, specifically in the functions of the cholinergic, serotonergic, and catecholaminergic systems in subcortical areas, which can produce diffuse cortical hypoactivity.…”

Association of electroencephalogram epileptiform discharges during cardiac surgery with postoperative delirium: An observational study

“…Fritz et al ( 33 ) found that a longer duration of intraoperative EEG suppression is associated with a higher occurrence of delirium. Eskioglou et al ( 34 ) found that the EEG of patients with delirium in the intensive care unit may demonstrate burst suppression, rhythmic or periodic patterns, and seizures or status epilepticus. Patients with delirium also show increased slow-wave activity involving the occipitoparietal and frontal cortex with disruption of functional connectivity ( 35 ).…”

Diagnóstico de delirium em pacientes admitidos em Unidade de Terapia Intensiva: uma revisão integrativa

“…A inflamação tem sido relacionada a fisiopatologia do delirium, sendo que a razão plaqueta-linfócito (PLR) relatada como um marcador da resposta inflamatória em várias doenças (doença cardiovascular, lesão renal aguda, câncer, etc). Desta Eskioglou et al (2021), compararam achados de eletroencefalograma (EEG) -exame não invasivo e amplamente disponível -em pacientes delirantes versus não delirantes. Pacientes delirantes apresentaram maior frequência na supressão de surtos (10 vs 0%, p=0,02), nos padrões rítmicos/periódicos (43% vs 22%, p=0,03) e na atividade epileptiforme (7 vs 0%, p=0,05), independente da sedação ou analgesia.…”