MIND-ICU Study: Delirium and Dementia in Veterans Surviving ICU Care

Advances in critical care have led to improved survival among those admitted to intensive
care units (ICUs). However, survival is lower among those who develop ICU delirium, and the
quality of life among survivors may be affected by post-ICU long-term cognitive impairment
(CI) that lasts months to years. Long-term CI has been studied predominantly following
cardiopulmonary bypass. In the much larger group of medical and general surgical ICU
patients, the extent of this problem and its relationship to health-related quality of life
is poorly characterized. Evidence from 6 pilot cohorts (including our own) totaling ~300
patients suggests that an astonishing 30% to 80% of ICU survivors experience long-term CI
functionally equivalent to mild/moderate dementia although it may not be progressive (and
thus will be referred to as long-term CI). Interestingly, this cognitive impairment arises
independent of severity of illness, and older patients appear particularly prone. Our work
and the work of others have shown that delirium is a major independent risk factor for
impaired cognitive function at hospital discharge and increased mortality at 6 months. While
it is not clear whether delirium itself is injurious to the brain or is simply a marker of
brain injury, it is clear that the onset of delirium in the ICU should not be considered
innocuous; rather, it may be a determinant of long-term CI and health-related quality of
life. Having spent the last 8 years studying delirium and drug exposure during acute phases
of critical illness and long-term CI after hospitalization, the investigators are thoroughly
prepared to continue the next phases of investigation in VA (Department of Veterans Affairs)
patients, many of whom are older and disproportionately at risk for adverse outcomes
following ICU care.

Inclusion Criteria:

- Patients will be included if they are adult patients in a medical and/or surgical ICU
receiving treatment for any of the following: respiratory failure or cardiogenic or
septic shock.

Exclusion Criteria:

Patients who meet the inclusion criteria will be excluded if they meet any of the
following criteria:

- Cumulative ICU time > 5 days in the past 30 days, not including the current ICU stay,
as this might create a state of flux regarding patients' cognitive baseline.

- Severe cognitive or neurodegenerative diseases that prevent a patient from living
independently at baseline, including mental illness requiring institutionalization,
acquired or congenital mental retardation, known brain lesions, traumatic brain
injury, cerebrovascular accidents with resultant moderate to severe cognitive
deficits or ADL dependency, Parkinson's disease, Huntington's disease, severe
Alzheimer's disease or dementia of any etiology.

- ICU admission post cardiopulmonary resuscitation with suspected anoxic injury

- An active substance abuse or psychotic disorder, or a recent (within the past 6
months) serious suicidal gesture necessitating hospitalization. This exclusion that
will enrich follow-up rates by avoiding patients with whom it is particularly
challenging to maintain long-term contact.

- Blind, deaf, or unable to speak English, as these conditions would preclude our
ability to perform the follow-up evaluation interviews.

- Overly moribund and not expected to survive for an additional 24 hours and/or
withdrawing life support to focus on comfort measures only.

- Prisoners.

- Patients who live further than 200 miles from the study site and who do not regularly
visit the study site area.

- The onset of the current episode of respiratory failure, cardiogenic shock, or septic
shock was >72 hours ago.

- Patients who have had cardiac bypass surgery within the past 3 months (including the
current hospitalization).

- Patients who are homeless and have no secondary contact person available. This
exclusion will enrich follow-up rates by avoiding patients with whom it is
particularly challenging to maintain long-term contact.