Is Density Spectral Array Display Along With Bispectral Index Superior to the Display of Bispectral Index Alone

A study to evaluate the use of density spectral array display in comparison with Bispectral index in a clinical setting.

Propofol-based total intravenous anesthesia (TIVA) is a popular general anesthesia (GA) technique with an increased risk of unintended awareness under GA, which can be a devastating and life-changing complication. Age-related changes may impact the performance of EEG-derived depth of anesthesia indices in those older than 65 years, particularly in the presence of cognitive disorders. Hypothesis: In comparison to monitor 1 (BIS only), monitor 2 (DSA + BIS) will have higher sensitivity and specificity to detect recovery Objectives: Investigators will prospectively measure the sensitivity and specificity of monitor 1 versus monitor 2 in patients older than 65 years receiving propofol-based TIVA. Methods: Investigators will recruit 70 participants from the Royal Brisbane and Women's Hospital (RBWH) who are aged 65 years or older and scheduled for elective endovascular or endoscopic urologic procedures. Investigators aim to determine whether the display of DSA can enhance the sensitivity and specificity of depth of anesthesia monitors in detecting sudden changes in anesthetic depth in older patients. This may enhance the detection of inadequate administration or delivery of propofol and may lower the incidence of unintended awareness under general anesthesia in that age group.

Inclusion Criteria: * Age ≥ 65 years undergoing elective procedures of 1-3 hours' duration requiring GA. * Procedures in which a DoA monitor can be applied to the forehead. * Patients receiving intravenous propofol and opiate anaesthesia using supraglottic airway device. * Patient able to provide informed consent. Exclusion criteria: * Administration of ketamine/dexmedetomidine. * Administration of inhaled anaesthetic agents or nitrous oxide * Administration of muscle relaxation