Please select the eligibility criteria that correspond to the clinical trial below.
Title: Investigation on the Diagnostic and Predictive Value of Bilateral Bispectral Index (BIS)-Monitoring in Cardiac Surgery
Brief Summary: The bispectral index (BIS) is derived from a single-channel electroencephalogram (EEG) and provides information on the anaesthetic depth. Recently, a bilateral two-channel EEG-sensor has been introduced to monitor the BIS on both cerebral hemispheres. In some patients significant left-right differences may occur, whereas no relevant side differences are expected in the majority of patients.

The aim of this study is to

* investigate the incidence, duration and degree of left-right BIS differences
* examine the relation between BIS differences and occurrence of cognitive deficits


Options:
A: Inclusion:

* Patients 60 years old and older,
* Competent to provide informed consent
* Undergoing major elective surgery that requires a minimum stay of 2 days postoperatively (e.g., open cardiac surgery, open thoracic surgery, major vascular surgery, intra-abdominal surgery, open gynecologic surgery, open urologic surgery, major orthopedic surgery, open hepato-biliary surgery and major ear, nose and throat surgery)

Exclusions

* Neurosurgical procedures will be excluded as surgery on the brain can confound the outcome (postoperative delirium).
* Patients with preoperative delirium and patients who are unable to participate adequately in delirium screening including those who are blind, deaf, or illiterate or fluent in languages other than English.
B: Inclusion Criteria:

MUST HAVE:

General Anesthesia with volatile anesthetic

PATIENT CHARACTERISTICS

Major Criteria (Must have any 1 of the following:)

1. Planned open heart surgery
2. Medications - anticonvulsants, abuse of opiates, benzodiazepines, cocaine
3. EF\<40%
4. Prior history of awareness (recall)
5. History of difficult intubation or anticipated difficult intubation
6. ASA IV or V status
7. Aortic stenosis
8. End stage lung disease
9. Marginal exercise tolerance not secondary to musculoskeletal dysfunction
10. Pulmonary hypertension
11. Daily alcohol consumption

Exclusion Criteria:

1. Surgical procedure that prevents the use of the BIS (e.g. surgery of forehead)
2. Patient positioning prevents use of the BIS
3. Surgery with wake-up test.
4. Less than 18 years of age
5. Vulnerable populations, such as those with dementia and those unable to provide informed consent.
6. Stroke with residual neurological deficits

   -
C: Inclusion Criteria:

* patients scheduled for cardiac surgery

Exclusion Criteria:

* pregnancy
D: Inclusion Criteria:

* Adult patients (\>65 years old)
* Scheduled for elective surgery requiring general anesthesia at LLUMC HSH
* Airway management expected to include endotracheal intubation
* Expected surgical duration 120 to 240 minutes

Exclusion Criteria:

* Pre-existing significant psychiatric disease or mental status changes
* Clinically significant cardiovascular, respiratory, hepatic, renal,neurological, psychiatric, or metabolic disease
* Patient's weighing \>50% ideal body weight

  * Men: Ideal Body Weight (in kilograms) = 50 + 2.3 kg per inch over 5 feet
  * Women: Ideal Body Weight (in kilograms) = 45.5 + 2.3kg per inch over 5 feet
* Patients who have undergone a general anesthetic within the past 7 days
* Patient refusal

Answer: C