Validation of Frontal EEG to Formal Polysomnography in the ICU

Validation of Frontal Limited Lead Electroencephalography (EEG) to Formal Polysomnography (PSG) in the Intensive Care Unit (ICU)

The purpose of this study is to compare a 2-lead frontal electroencephalogram recording to a formal polysomnography (PSG) in detecting sleep vs. wake and depth of sleep in both healthy and ICU patients.

Sleep in the intensive care unit (ICU) is poor and not well understood. Formal polysomnography (PSG) is the gold standard measure, but impractical for critical care. The relative influence of environment, illness and interventions on sleep in critically ill patients is therefore essentially unknown. Interventions to improve sleep have been pragmatic and outcomes subjective or indirect, and uninformed. When it is done, formal PSG in critical illness demonstrates fragmented, shortened, interrupted and non-circadian sleep, with environmental noise, light, and frequent physical stimulation causing arousals.

Group 1: Healthy Subjects in Sleep Lab:

Inclusion Criteria

• Age 18 or older
• Scheduled for a standard of care polysomnography lasting at least 8 hours for any condition

Exclusion Criteria

• Patient/Legally Authorized Representative declines consent

Group 2: ICU patient, not sedated, not ventilated

Inclusion Criteria

• Age 18 or older
• Anticipated to stay in intensive care unit overnight (minimum 8 hours)
• Glasgow Coma Scale score of 13 or great

Exclusion Criteria:

• Intubated with endotracheal tube
• Sedated (includes sedative drugs such as propofol, Dexmedetomidine, versed infusion above 2mg/hr, ketamine infusion above 0.2 mg/kg/hr).

Group 3: ICU patient, sedated and ventilated

Inclusion Criteria:

• Age 18 or older
• Anticipated to stay in the intensive care unit overnight (minimum 8 hours)
• Intubated, sedated, and ventilated

Exclusion Criteria:

• Presence of traumatic brain injury
• Planned extubation in next 8 hours
• Scheduled to leave the intensive care unit for any reason in the next 8 hours
• Anticipated life expectancy of less than 24 hours
• Electroencephalogram monitoring (current or scheduled in the next 8 hours)
• Hemodynamic instability (defined as: (i) mean arterial pressure <60mmHg for >20 minutes with efforts to raise it or (ii) >2 liter fluid administered in 2h after operating room and anticipating on-going needs for fluid resuscitation or (iii) ICU MD determination of "atypical and profound hemodynamic instability" or (iv) PI determination after evaluation.
• Refractory hypoxemia - defined as Saturation <88% on Sp02 despite efforts to increase it
• Hemorrhage - defined as >500cc chest tube output in 2h and anticipated need of more than 2 units of packed red blood cells in immediate post op period. This does NOT include cell-saver.