The dreaming reported by many patients during surgery, in most cases, does not mean the anesthesia is wearing off, Australian researchers report in the journal Anesthesiology, according to Reuters. Few studies have looked at the link between dreaming and the depth of anesthesia, and studies that have investigated the topic have yielded inconclusive results, lead author Dr. Kate Leslie, from Royal Melbourne Hospital, and colleagues report. They point out that dreams experienced under anesthesia can be distressing to patients, and some may think their dream was actual awareness resulting from inadequate anesthesia. In their study, the researchers assessed 300 consecutive healthy patients who were undergoing elective surgery that required general anesthesia. The Bispectral Index, a measure of the anesthetic effect on the brain, was used to gauge the depth of anesthesia during surgery. After the surgery was over, the patients were interviewed about their dreams. Twenty-two percent of patients reported dreaming. No statistically significant difference in the average Bispectral Index value was noted between the dreamers and patients who didn't dream, the report indicates. Patient characteristics that were associated with dreaming during anesthesia included younger age, male gender and frequent recall of dreams at home. Dreamers where also more likely to be treated with the anesthetic propofol or receive regional anesthesia and were more likely to open their eyes sooner after surgery. Dreams experienced under anesthesia were similar to those during sleep, were usually pleasant, and the content was unrelated to the surgery, the authors note. The similarities between the patients' dreams while under anesthesia and during natural sleep suggest that the dreams during anesthesia occur during the early recovery period when patients are still lightly sedated, but are in a definite sleep state, Leslie's team concludes. These findings, the researchers conclude, should reassure patients who may think dreaming during surgery is a sign of inadequate anesthesia.
