Many surgery patients believe anesthesia puts them to sleep. A review article published in the New England Journal of Medicine reveals general anesthesia is a reversible coma, not sleep. Teaming neuroscience and sleep medicine, the article provides a framework for a better understanding of general anesthesia and its relation to sleep and coma.
The lead author, Emory Brown, MD, PhD, is from the Massachusetts General Hospital Department of Anesthesia, Critical Care and Pain Management. Co-authors were Ralph Lydic, PhD, a sleep expert from the University of Michigan and Nicolas Schiff, MD, a coma expert from Weill Cornell Medical College. The researchers compared the physical signs and electroencephalogram (EEG) patterns of general anesthesia and sleep.
The article explains the significant differences between sleep and anesthesia. The following are key points from the review article.
- Only the deepest stages of sleep are similar to the lightest phases of anesthesia
- Natural sleep has predictable phases, while general anesthesia takes patients to the phase that is most appropriate for the procedure
- General anesthesia phases for surgery most resemble states of coma
The study suggests other uses for anesthesia. For example, very low doses of ketamine shows reduced symptoms in chronically depressed patients. The article also describes the case of a brain-injured patient who recovered some function through the administration of the sleep-inducing drug zolpidem (Ambien).