Electroencephalography Guidance of Anesthesia

Delirium is one of several geriatric syndromes, and is among the most common postoperative
complications, affecting up to 70% of surgical patients older than 60. Delirium is an acute
change that manifests as inattention and inability to think logically, and is deeply
distressing to patients and their families. Based on our surveys of 1,000 surgical patients,
over 30% were worried about experiencing delirium. Delirious patients are unable to
participate effectively in rehabilitation exercises and are susceptible to other geriatric
syndromes, like falls. The occurrence and duration of delirium are associated with longer
intensive care unit and hospital stay, persistent cognitive deterioration, hospital
readmission and increased mortality rate. Additionally, delirium carries a huge social and
economic burden, costing over $60,000 per patient per year. Despite the importance of
delirium to patients and to society, no approach has been proven to prevent postoperative
delirium. Furthermore postoperative delirium is frequently unrecognized, and surgical
patients are not followed systematically after they are discharged from hospital. Without
diagnosing delirium or following patients postoperatively, we are limited in our ability to
test the effectiveness of any intervention to prevent or treat postoperative delirium and its
sequelae. There is mounting evidence that electroencephalography guidance of general
anesthesia can decrease postoperative delirium. Specifically, our group has found that a
suppressed electroencephalogram pattern, which occurs with deep anesthesia, is associated
with increased delirium and death after surgery. The Electroencephalography Guidance of
Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) Study will therefore compare the
effectiveness of two anesthetic protocols for reduction of postoperative delirium. One
protocol will be based on current standard anesthetic practice, and the other protocol will
be based on electroencephalography guidance. We also expect to determine the impact of the
anesthetic protocols on patient reported outcomes of health-related quality of life. At
Washington University, we have successfully implemented an ambitious study that enrolls
patients at the preoperative assessment clinic, and tracks their health and wellbeing at 30
days and at 1-year postoperatively. This will enable us to assess the consequences of
postoperative delirium and to determine whether anesthetic management can impact patient
reported outcomes, such as health-related quality of life. We shall also explore whether a
multi-component safety intervention for delirious patients prevents downstream adverse
events, like falls. The ENGAGES study - through its structured anesthesia protocols, its
thorough approach to delirium assessment, and its ability to track patients' health and
wellbeing postoperatively - is poised to make a major contribution to the care of elderly
patients who are at risk of postoperative delirium and other adverse outcomes.

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.