Please select the eligibility criteria that correspond to the clinical trial below.
Title: B-Unaware Study: Comparison of BIS-guided Anesthesia With End-Tidal Volatile-Guided Anesthesia to Decrease The Incidence of Awareness During High-Risk Surgery
Brief Summary: The overall purpose of this study is to see if a Bispectral Index (BIS) monitor, a Food and Drug Administration (FDA) approved brain monitoring device, will help to reduce the risk of patients remembering being awake during surgery. The BIS monitor may be able measure how asleep a patient is during surgery. Using the BIS monitor to guide anesthesia will be compared with using the concentration of anesthetic gas to guide anesthesia.


Options:
A: Inclusion Criteria:

* Patients received general anesthesia with tracheal intubation or LMA
* Apparently normal mental status

Exclusion Criteria:

* Pediatric patients (\<12 yr)
* Those who could not be interviewed in 24 hours after the operations
* Those unable to communicate in common spoken Chinese
B: Inclusion Criteria:

MUST HAVE:

General Anesthesia with volatile anesthetic

PATIENT CHARACTERISTICS

Major Criteria (any 1 of the following:)

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

Minor Criteria (any 2 of the following)

1. Beta blockers
2. COPD
3. Moderate exercise tolerance not secondary to musculoskeletal dysfunction
4. Smokes ≥2 packs per day
5. Morbid obesity BMI\>30 -

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:

1. Males and females, age 18 years and over
2. Planned general anaesthesia for surgery that includes a skin incision and expected to exceed two hours, and the patient is expected to be in hospital for at least three days

Exclusion Criteria:

1. Endoscopic or radiological procedures
2. Cardiac surgery
3. Marked impairment of gas-exchange (requiring Fi02\> 0.3)
4. Thoracic surgery requiring one-lung ventilation (requiring Fi02\> 0.3)
5. Specific circumstances where N2O is contraindicated (eg. volvulus, pulmonary hypertension, raised intracranial pressure)
6. Lack of provision of N2O.
D: Inclusion Criteria:

* patients scheduled for bronchoscopy
* ASA I to III
* age between 18 and 79 years
* capacity of discernment

Exclusion Criteria:

* visual and psychological problems that might interfere with psychometric testing
* chronic obstructive pulmonary disease with FEV1 \< 50% predicted
* need for an airway intubation or laryngeal mask insertion
* fever or other signs of systemic infection
* hemodynamic instability defined as a resting heart rate (HR) \< 60 or ≥ 120 and/or a systolic blood pressure (BP) \< 100 or \> 180 mmHg
* significant liver disease and documented soy allergy

Answer: B