Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Prospective, Randomized, Controlled Trial Comparing Bispectral Index Monitoring to Electronic Alerts for Prevention of Awareness During Anesthesia in the General Population
Brief Summary: Awareness during anesthesia is a problem receiving increased attention by patients, clinicians, and the general public. The incidence of intraoperative awareness has been reported to be between 1-2/1000 cases, but recent data suggest that this may be an overestimate. The Bispectral Index (BIS) Monitor is an electroencephalographic method of assessing depth of anesthesia that has been shown in one study to reduce the incidence of awareness during anesthesia in the high-risk population (Myles et al, 2004). In the study of Myles et al, the number needed to treat (NNT) in order to prevent one case of awareness in the high-risk population was 138, with an associated cost of approximately US$2200. Since the NNT and the associated cost of treatment would be much higher in the general population, the efficacy of the BIS monitor in preventing awareness in all anesthetized patients needs to be clearly established. Furthermore, recent data suggest that the BIS may not be useful in the high-risk population. The investigators propose a prospective, randomized, controlled trial comparing the BIS monitor to electronic alerts based on non-electroencephalographic gauges of anesthetic depth.


Options:
A: Inclusion Criteria:

* General anaesthesia with controlled ventilation

Exclusion Criteria:

* Age lower than 18 years
* Pregnant woman
* Allergy to the propofol or to a muscle myorelaxant
* Patients receiving a psychotropic treatment
* Presence of a central neurological disorder or a lesion cerebral
* Patients having an anomaly of blood cells count preoperative biological assessment
* Patients having had an anaesthesia in the previous month
B: 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.
C: Inclusion Criteria:

* At least 18 years of age, English-speaking, available for follow-up interview at one month.

Exclusion Criteria:

* Pre-existing neurologic or neuropsychiatric condition, surgical manipulation around forehead, not available for follow-up interview.
D: 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

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Answer: C