Reducing postoperative delirium with brain activity monitoring
As elderly patients undergo anesthesia, their brains emit electrical signals, the results of which are measurable as an electroencephalogram (EEG). Monitoring these signals and adjusting anesthetic dosages accordingly may reduce the risk of postoperative delirium (POD) and prevent intraoperative awareness. The QUESTIONED project, supported by the Bern MedTech Collaboration Call (BMCC), investigates this approach to enhance anesthesia care and patient outcomes.
Addressing the growing challenge of POD
Switzerland's aging population mirrors trends in other developed nations, increasing pressure on its healthcare systems. The demand for surgery, especially among the elderly, is rising. This demographic is especially susceptible to postoperative delirium (POD)—a complication that can lead to severe long-term consequences.
POD not only jeopardizes patient health but also imposes a substantial economic burden. In the U.S. among Medicare-eligible patients undergoing major elective surgeries, POD is estimated to add $32.9 billion annually to healthcare costs—a figure expected to rise significantly when accounting for the general population.
Burst suppression EEG displaying alternating high-amplitude bursts and flat suppression periods. Burst suppression is a pattern observed in EEG recordings, showing alternating periods of high-amplitude brain activity (bursts) and low-amplitude or flatline activity (suppression). This pattern is often seen in patients under deep anesthesia and may indicate excessive sedation.
Understanding postoperative delirium
Postoperative delirium manifests as sudden and fluctuating cognitive disturbances following surgery. Clinically, POD is linked to increased morbidity, mortality, prolonged hospital stays, and higher medical expenses. Other complications—such as intraoperative awareness and hypotension—also pose significant health risks and strain healthcare resources. Researchers have identified "burst suppression"—periods of alternating high and low brain activity detectable via EEG during anesthesia—as a potential predictor of POD. Accurate EEG monitoring emerges as an essential tool in mitigating these risks.
Advancing EEG monitoring technologies
Launched in 2024, the QUESTIONED project represents a significant advancement in EEG monitoring technology. Led by Dr. Darren Hight from the Department of Anesthesiology and Pain Medicine at Inselspital, Bern University Hospital, and Prof. Heiko Kaiser, Consultant in Anesthesia & Intensive Care at Hirslanden Klinik Aarau and Professor of Anesthesiology at the University of Bern, the initiative benefits from the technological expertise of CSEM.
Introducing ULTEEMNite: Lightweight, wearable EEG monitoring
Building upon a system developed by CSEM in collaboration with Inselspital, Bern University Hospital, the project introduces ULTEEMNite—a lightweight, wearable device integrating advanced dry electrode technology to capture frontal EEG signals. Originally designed for sleep monitoring, ULTEEMNite is being adapted to allow anesthesia providers to monitor EEG activity during procedures.
“ULTEEMNite’s high sensitivity and reusability offer a cost-effective alternative to traditional EEG devices,” says Gürkan Yilmaz, a Senior Expert in MedTech from CSEM. “Weighing under 20 grams, it’s easy to position on the patient during anesthesia. Our proprietary dry electrodes measure the patient’s brain activity during surgery, eliminating the need for expensive single-use scalp electrodes.”
The rechargeable device communicates via Bluetooth™ Low Energy protocol with a portable device. “It connects to an interface that will display the patient’s EEG signals, interpreted by a custom algorithm, allowing anesthesiologists to detect subtle neurological changes in real-time," Yilmaz explains.
Practical advantages over conventional monitoring systems
“In Switzerland, EEG monitoring during surgery is underused. Conventional depth‑of‑anesthesia monitors, like the Bispectral Index monitoring system, analyze EEG data which is then also displayed as a numerical index to gauge anesthesia depth. Also, these systems typically rely on single-use EEG electrodes, which increases operational costs,” notes Dr. Hight.
“However, these systems have clinical limitations. Research shows that the processed EEG indices produced by these systems can misinterpret anesthesia depth—especially in older patients—potentially leading to improper dosing. As a result, they are often reserved for high-risk procedures. Our solution by lowering cost and complexity has the potential to improve dosing and bring EEG-based monitoring to a broader range of surgeries," he adds.
More accurate dosing can reduce medication waste, minimize complications, shorten hospital stays, and improve resource efficiency. ULTEEMNite’s reusable design also provides an environmental advantage by cutting down on single-use electrode waste.
A person comfortably wearing CSEM’s ULTEEMNite device for EEG monitoring
Close-up of ULTEEMNite’s central unit and sensor nodes with active-dry electrodes.
Training healthcare professionals for better integration
“Another pivotal aspect of this project is its strong educational component,” explains Prof. Kaiser. “Interpreting raw EEG data effectively requires specialized training. Our goal is to equip anesthesiologists with the skills to accurately interpret comprehensive EEG displays, enabling them to correctly recognize critical patterns—including those associated with POD.” This targeted training initiative will help support the integration of ULTEEMNite and EEG interpretation into everyday clinical practice, promoting broader adoption across the field.
From research to real-world impact
Interdisciplinary collaboration underpins the QUESTIONED project success. It aligns with healthcare policy goals in Bern and Switzerland, positioning Bern as a leading MedTech hub. The project has already attracted interest from public and private healthcare institutions, who are eager to bring the solution to pre-clinical trials.
“We aim to transition our BMCC-funded project into a scalable start-up, leveraging public funding for commercialization,” says Dr. Hight. “With support from agencies like Innosuisse, for example, our goal is to build a sustainable start-up, create jobs in the Canton of Bern, and bring this technology to market.”
Looking ahead
As Switzerland’s elderly population grows, innovative approaches like that pursued through this project could become essential. Reducing POD and intraoperative awareness, improving recovery outcomes, and alleviating pressure on the Swiss healthcare system are key objectives.
“With continued validation and adoption, our initiative could contribute to safer and economically viable anesthesia practices for vulnerable surgical patients,” Dr. Hight and Prof. Kaiser conclude.