Dreaming is a common part of the anesthetic experience, but it remains a poorly understood phenomenon. Few studies have assessed the relationship between dreaming and depth of anesthesia, and their results were inconclusive. Anesthesiology (January 2007) features a new Australian study conducted at 3 university hospitals in Melbourne and Perth, which documented that many patients have dreams and that most are pleasant or even prompted by an overheard conversation while under anesthesia. This investigation is important because dreaming is one of the most common side effects of anesthesia, which patients can sometimes confuse with having been aware during surgery. The study consisted of 300 healthy patients, from 18 to 50 years, who were having elective surgery with general anesthesia. In addition to the usual monitors utilized during surgery, each patient was also monitored with a device that measures an effect of anesthetics and sedatives on the brain. The patients were first interviewed about their dreams when awakening from anesthesia, with a second interview held 2 to 4 hours after the operation. Of the 300 patients, nearly one third (86) reported dreaming during anesthesia in one or both of the interviews. At the first interview, 47 patients described having a dream, and at the second interview, 53 patients described having a dream. Of the 35 patients who reported dreams at both interviews, 31 reported the same dream both times, and 4 patients reported different dreams at each interview. There were no clinically significant differences between dreamers and nondreamers in the monitor value used during anesthesia to measure the effects of anesthetics and sedatives. The findings showed that most dreams were pleasant and meaningful to the patient (family, friends, work, or recreation). Others were inspired by overheard conversations among the surgical team members. The evidence from this study supports the hypothesis that dreaming actually occurs during recovery and is not associated with light or inadequate anesthesia in the vast majority of cases.
(Source: American Society of Anesthesiologists, January 3, 2007)
