1. Eric Mauri Michael Marquis Matthew Kasztejna Advised by: Dr. Wes Ely
Delirium Detection
Eric Mauri
Michael Marquis
Matthew Kasztejna
Advised by: Dr. Wes Ely

2. Delirium Overview Brain’s form of organ dysfunction
Defined as a disturbance of consciousness characterized by an acute onset and fluctuating course of impaired cognitive functioning.
Develops in over 80% of ICU patients
Direct consequence of medical conditions, medication, toxin exposure, or a combination of all of these.
Ely et al. Seminars in Respiratory and Critical Care Medicine, Vol. 22, Num. 2, 2001.

3. Delirium Demographics
Occurs in 15-60% of general patients and most frequent complication of hospitalization in older patients
Complicates 2-3 million people yearly.
Involves over 17.5 million inpatient days.
Over $4 billion in Medicare expenditures.
Development of delirium selected as one of the top three most important areas for quality of care improvement in older adults.
Ely et al. Seminars in Respiratory and Critical Care Medicine, Vol. 22, Num. 2, 2001.

4. How is it detected? Arousal and Attention Assessment
Confusion Assessment Method (CAM-ICU)
Acute onset of mental changes
Inattention
Disorganized thinking
Alertness
Patients are determined to be CAM-positive if they have both features 1 & 2 and either feature 3 or 4.

5. CAM-ICU Cont. Example Questions Problems
As part of the inattention assessment patients are shown a set of 5 pictures, then a set of 10 pictures (5 of which were in the original set) The are asked whether the picture was in the first set, if they get more than 3 wrong then they are inattentive.
As part of the disorganized thinking assessment they are asked questions like: Will a stone float on water? Are there fish in the sea? Can you use a hammer to pound a nail?
Problems
Subjective
No Standardization
Time Intensive

6. Project Objectives
Develop system that can continuously measure delirium in ICU patients
Device must be small, cost-effective, comfortable, and practical
Real-Time measurements, data storage, and analysis of information (software)

7. Proposed Solution Quantitative EEG Benefits Acquire digital signal
Transform it into the frequency domain
Focus on certain frequency bands that have been clinically shown to be important to sleep.
Benefits
Inexpensive
Noninvasive
Software reduces man hours
Most importantly several studies have shown that EEG can be effectively used to monitor sleep

8. Stages of Sleep Stage 1 – Frequency 4 to 8 Hz, 5% of total sleep
consists mostly of theta waves (high amplitude, low frequency (slow))
brief periods of alpha waves, similar to those present while awake
Stage 2 – Frequency 8 to 15 Hz, 50 % of total sleep
peaks of brain waves become higher and higher (sleep spindles)
k-complexes (peaks suddenly drastically descend and then pick back up) follow spindles
Stage 3 & 4 - Frequency .5 to 4 Hz, 7 & 11% respectively
very slow brain waves, called delta waves (lower frequency than theta waves)
REM - Frequency > 12 Hz, ~ 25% increases as night goes on
beta waves have a high frequency and occur when the brain is quite active, both in REM sleep and while awake

9. Possible Systems Gold Standard EEG – Sleep Labs
Bispectral Index (BIS) – Aspect Medical
Sleep I/T
Vitaport - Temec

10. Ruled out systems Gold standard EEG BIS Most complex
The 26 lead system is too complicated for use in the ICU.
BIS
Simplest
Derived from measurements of frequency, amplitude and coherence of EEG.
3 lead system which produces a single number to describe changes in EEG that relate to levels of sedation and consciousness.

11. BIS Problems
Studies have shown that BIS is only effective for the first 3 stages of sleep.
During sleep the BIS number decreases as sleep progress from the first to third stage, however the number increases during REM sleep due to increased glucose metabolism in the brain.
Modified system would be too experimental for Dr. Ely’s work.

12. Remaining Possible Systems
Sleep I/T and Vitaport
Both systems are full clinical Polysomnographs (EEG, EOG, EMG, EKG, respiratory effort, oxygen saturation)
While currently too complex for ICU, the potential for simplification exists.
Dr. Ely prefers focus on Vitaport because it is seems to be best combination of (1) a validated sleep monitoring system and (2) a viable and practical method for use in ICU patients

13. Vitaport
Cost: 6,500 for Vitaport 3 recorder base, with marker, manual, case, Columbus setup software
Dr. Weinhouse's has a main license, a site-license would cost 15 % of the original price.
Dr. Ely would like to lease the system; depending upon how long we lease, it would be 10%-15% of the sales price (per month)
Problems
3-4 weeks for delivery
Difficulty in contacting Dr. Ely

14. Current Work
Educating ourselves about the Vitaport system and its features.
Working out agreement with Temec about obtaining a Vitaport system for experimentation.
Meet with Dr. Ely to determine design specifications of Vitaport and discuss possible modifications and requirements.
Informing Dr. Ely about the existence of SNAP

15. Future Work
Continue working with Dr. Weinhouse and engineers at Temec.
To acquire Vitaport system and make necessary modifications so Dr. Ely will be able to test the system and run experiments after we are gone.