Unexpected awareness and memory in the perianesthesia setting

Unexpected awareness and memory with general anesthesia are phenomena that can occur in the intriguing interface between consciousness and unconsciousness. Studies suggest that, for some patients, cognitive processing remains active even during deep anesthesia; that is, an apparently unconscious patient still may be registering information. Although explicit memory is usually eliminated by general anesthesia, implicit or subconscious memory may remain. There is no monitor to tell where the patient lies on the continuum between consciousness and unconsciousness. "Sleeping" patients are vulnerable to overhearing inappropriate conversation that may have negative consequences. Post-traumatic stress disorder as well as medical malpractice litigation may result from awareness or memory during anesthesia. Implications for the use of opioids, benzodiazepines, and muscle relaxants in the perianesthesia setting as well as nursing interventions addressing unexpected awareness or memory are discussed.