Monitoring more vital body signals could yield better usage of anesthesia, researchers find

Posted On September 20, 2012 by Jeremy Craig
Categories Discovery Tags ,

ATLANTA – A Georgia State University physicist and his European colleagues have found a better way to monitor the use of anesthesia, findings that may help to reduce the number of patients who wake up while anesthetized during surgery.

Mukesh Dhamala, assistant professor of physics at GSU and colleagues at the Ecole Polytechnique Federale de Lausanne in Switzerland researched how the cortical (nervous) and cardiovascular systems behave during anesthesia.

They found that using a combination of brain, heart-rate and respiration signals together is better at evaluating anesthesia levels than the current practice of using brain signals alone.

“A network measure based on the signals from multiple organs can evaluate the depth of anesthesia better than a measure based on a single organ,” Dhamala said.

Using the physics of interdependent organs that the team researched could cut down on the phenomenon of what is called anesthesia awareness, Dhamala explained.

The findings were published in the Public Library of Sciences journal PLoS ONE.

Using anesthetics properly on patients requires constant monitoring. While using too much anesthetics can kill a patient, there’s a risk that using too little will cause a patient to become conscious and aware of their surroundings.

According to the Joint Commission (formerly the Joint Commission on Accreditation of Healthcare Organizations), the incidence of awareness may be as high as 1 to 2 for every 1,000 patients – translating to 20,000 to 40,000 cases of anesthetic awareness annually.

According to the American Society of Anesthesiologists, awareness is rare, but can occur often in high-risk surgeries, such as trauma and cardiac surgery where the patient’s condition may not allow for the usual dosage of anesthetic drugs.

The society reports that most patients experiencing this phenomenon do not feel pain, but the experience can be very disturbing and traumatic for others, with some patients even needing counseling after surgery.

The study, “Cortico-Cardio-Respiratory Network Interactions during Anesthesia,” is available online at

Sept. 20, 2012