Overview

This study is designed to test the hypothesis that poor cerebral perfusion during critical illness is a risk factor for acute and long-term neurological dysfunction among survivors. We use near-infrared spectroscopy to measure brain tissue oxygenation as a non-invasive surrogate marker for cerebral perfusion. Acute neurological dysfunction is defined as the presence of delirium, which is assessed using the Confusion Assessment Method-Intensive Care Unit (CAM-ICU). Chronic neurological dysfunction is defined as having quantitative impairments on robotic testing (KINARM robot) and traditional neuropsychological screening (Repeatable Battery for the Assessment of Neuropsychological Status).

Eligibility

Inclusion

1. Adults ≥ 18 years old
2. Admitted to a critical care unit requiring one or more of the following:

   (a) Respiratory failure requiring invasive mechanical ventilation with an expected duration >24 hours (b) Shock of any etiology. Shock is defined by the need for one of the following vasopressors/inotropes: (i) Dopamine ≥7.5 mcg/kg/min (ii) Dobutamine ≥5 mcg/kg/min (iii) Norepinephrine ≥5 mcg/min (iv) Phenylephrine ≥75 mcg/min (v) Epinephrine at any dose (vi) Milrinone at any dose (if used in conjunction with another agent) (vii) Vasopressin ≥0.03 u/min(if used in conjunction with another agent)

   Exclusion

3. Admission to the ICU > 24 hours
4. Life expectancy <24 hours
5. Admitting diagnosis that affects the central nervous system
6. Any reason that the subject may not be able to participate in the follow up assessments (i.e. limb amputation, paresis, neuromuscular disorders)