Prolonged Mismatch Negativity Latencies in Intensive Care Unit Patients With Active Delirium.

Area of Science:

• Neuroscience
• Critical Care Medicine
• Electrophysiology

Background:

• Delirium is a frequent and severe complication in critically ill patients, linked to increased mortality and cognitive deficits.
• Renal dysfunction is a known risk factor for delirium in the intensive care unit (ICU).
• Understanding the neurophysiology of active delirium episodes is crucial but underexplored.

Purpose of the Study:

• To investigate the neurophysiologic characteristics of delirium in critically ill patients with renal dysfunction.
• To utilize mismatch negativity (MMN) as an electrophysiologic marker to study brain activity during delirium.
• To explore the relationship between MMN, delirium severity, cognitive function, and clinical outcomes.

Main Methods:

• Auditory oddball paradigm used to record event-related potentials and measure MMN in ICU patients with renal dysfunction.
• MMN was calculated by subtracting responses to deviant tones from standard tones.
• MMN was compared between patients with and without delirium, and its association with cognitive function, disease severity, and clinical outcomes was assessed.

Main Results:

• Patients with delirium exhibited significantly prolonged MMN latencies compared to those without delirium (P = 0.005).
• Delayed MMN latencies showed a trend towards association with increased delirium severity.
• MMN did not predict clinical outcomes at ICU discharge.

Conclusions:

• Critically ill patients with renal dysfunction demonstrate prolonged MMN latencies during delirium.
• These findings suggest altered neural processing in the brains of ICU patients experiencing delirium.
• MMN may serve as a valuable marker for understanding delirium pathophysiology in this population.