Less Anesthesia During Surgery Does Not Prevent Postoperative Delirium

Postoperative delirium is a state of agitation or confusion in the days following a procedure involving anesthesia. It is most common in older patients, with nearly 25% of them experiencing this unpleasant event after surgery. In the past, researchers believed that very closely monitoring the brain of older patients during surgery, and reducing the amount of anesthesia used would prevent the confusion following a procedure. However, a new study suggests this is not the case and that less anesthesia during surgery does not prevent postoperative delirium.

Researchers from Washington University School of Medicine, studied 1,200 older patients undergoing surgery at the Barnes-Jewish Hospital in St. Louis, Missouri. Half of the patients were randomly selected to receive normal care during their procedure while the other half received very close and meticulous monitoring of brain activity measured by a electroencephalogram. The results showed that 23% of the patients that received normal care and monitoring suffered from postoperative delirium, and 26% of the patients that were closely monitored also suffered from the same delirium in the days after their surgery.

“The thought has been that at certain levels of anesthesia, brain activity is suppressed, and that is what mediates these problems,” said first author Troy S. Wildes, MD, an associate professor of anesthesiology. “But we found that preventing suppression by closely monitoring and then adjusting doses of anesthesia made delirium no less likely.”

The study did find that there were fewer deaths in the month after surgery among those who had their brain activity closely monitored as compared to those who did not. In those that had been monitored, less than 1% passed away within a month, while in the other group, 3% of the patients passed away within 30 days of their surgery.

The Principal investigator Michael S. Avidan, MBBCh, the Dr. Seymour and Rose T. Brown Professor of Anesthesiology said “I believe we should monitor the brain of every single patient during general anesthesia, just as we routinely monitor heart and lung function,” Avidan said. “Monitoring other organs during surgery has become the standard of care, but for some reason, even though the brain is the target of anesthesia drugs, this type of close monitoring and adjustment has never become routine.”
While these findings show less anesthesia during surgery does not prevent postoperative delirium postoperative, it did discover other findings that will be further researched. For more information on anesthesia, visit our website www.steelcityanesthesia.com.