Clinical trial NCT01983384: Anesthetic Depth and Postoperative Delirium Trial - 2
Official title: A Randomised Controlled Trial to Reduce Postoperative Delirium Through Reduction in Intraoperative EEG Suppression in Older Surgical Patients Undergoing Major Noncardiac Surgery
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Delirium
Cognitive Disorders
Keywords: Delirium
Cognition
Surgery
Anesthesia
Aging
Electroencephalography
Lead sponsor: University of California, San Francisco
Sponsor class: OTHER
Collaborators: name: Virginia Polytechnic Institute and State University
First posted: 2013-11-14
Enrollment: 205
Sex: ALL
Minimum age (years): 65
Standard ages: OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Patients will be assigned to receive processed EEG-guided anesthesia or standard anesthetic care. Patients in both groups will be monitored with processed EEG, however those in the standard care group will have the anesthesiologist blinded to the machine. Patients in the interventional group receive processed EEG-guided anesthetic maintenance.
Primary purpose: PREVENTION

Brief summary: Recent limited evidence suggests that anesthetic depth may influence postoperative cognitive outcomes, however, the mechanism between this association is unclear.

Detailed description: Recently, it has been proposed that use of a processed electroencephalogram (EEG) monitor during surgery may be associated with a lower rate of postoperative delirium. In fact, some suggest that older patients undergoing surgery should routinely be monitored with an anesthetic depth monitor to allow the titration of anesthetics or sedation medications to lighter levels to promote better postoperative cognitive outcomes. Recent studies, including preliminary results from our group, have demonstrated electroencephalogram (EEG) suppression to be an independent risk factor for postoperative delirium.

Prior studies that have focused on risk prediction have shown age and prior cognitive impairment to be the most consistent risk factors for postoperative delirium. However, as of yet, no clinical trial has identified a relationship whether use of processed EEG monitor resulted in a reduction of incident postoperative delirium through a reduction in EEG suppression, with proper consideration of patients' baseline cognitive status as a potential moderator. Additionally, use of anesthetic depth monitor to keep patients' anesthetic depth above a specified value has never been validated or proven to be feasible or safe.

Accordingly, the investigators plan an exploratory study to: 1) determine whether the use of processed EEG to keep anesthetic depth above a specified level, results in a reduction in EEG suppression when compared to standard anesthetic care, 2) to determine whether preoperative level of cognitive function moderates the effect of group assignment on EEG suppression, and 3) to determine the feasibility and safety of using processed EEG-guided to keep patients' anesthetic depth above a specified value. A secondary aim was to determine the effect size for the intervention to reduce postoperative delirium for subjects with and without preoperative cognitive impairment for a future trial.

Eligibility criteria: Inclusion Criteria:

* 65 years and older of age undergoing non-cardiac surgery, requiring hospital stay of 2 or more days.

Exclusion Criteria:

* patients who are not fluent in English or cannot provide informed consent
* patients who may not tolerate either light or deep anesthesia (history of heart failure, coronary artery disease, substance abuse)
* history of intraoperative recall or awareness during anesthesia
* pathologies of the brain which may affect EEG monitoring
* patients who are anticipated to have consecutive surgery within 3 days of first procedure
* patients who have had surgery with general anesthesia in the past 30 days

Primary outcomes:
measure: Intraoperative EEG Suppression
timeFrame: Patients will be monitored by processed EEG intraoperatively, for the duration of surgery
Secondary outcomes:
measure: Preoperative level of cognitive function
timeFrame: Up to one week before surgery
measure: Patient intraoperative awareness and recall
timeFrame: Intraoperative recall and awareness will be measured within 72 hours after end of surgery
measure: Patient movement
timeFrame: During surgery
measure: Intraoperative systolic and diastolic blood pressure
timeFrame: During surgery
measure: Intraoperative heart rate
timeFrame: During surgery
measure: Anesthesiologists' adherence to assigned processed EEG index in the interventional group
timeFrame: Anesthesiologists complete self-report within 72 hours after end of surgery. This outcome measure is collected once for each patient through study completion, an average of 2 years.
measure: Postoperative delirium
timeFrame: Daily for three postoperative days.
Other outcomes:
Locations:
city: San Francisco
country: United States
facility: University of California, San Francisco Medical Center
state: California
Study officials:
affiliation: University of California, San Francisco
name: Jacqueline Leung, MD, MPH
role: PRINCIPAL_INVESTIGATOR
References:
citation: Tang CJ, Jin Z, Sands LP, Pleasants D, Tabatabai S, Hong Y, Leung JM. ADAPT-2: A Randomized Clinical Trial to Reduce Intraoperative EEG Suppression in Older Surgical Patients Undergoing Major Noncardiac Surgery. Anesth Analg. 2020 Oct;131(4):1228-1236. doi: 10.1213/ANE.0000000000004713.