Awareness during general anesthesia: An Indian viewpoint

BACKGROUND AND AIMS: The incidence of intra-operative awareness with explicit recall in the Western world has been reported to be between 0.1% and 0.2% in the general surgical population and up to 1–2% of patients at high risk for this complication. Awareness in the Indian population has never been studied; we therefore wanted to detect the incidence of awareness in patients who were at high risk of experiencing awareness during surgery in our population. MATERIAL AND METHODS: We conducted a prospective single-center observational study at a 600-bedded tertiary cancer care referral hospital. We recruited adult patients posted for major cancer surgery who were considered to be at high risk for awareness. These patients were interviewed at three time-points using the structured modified Brice interview questionnaire. The primary outcome studied was the incidence of definite intra-operative awareness. RESULTS: A total of 934 patients were included in the final analysis of which none reported awareness. Using the rule of three (Hanley and Lippman-Hand) we conclude that the upper 95% confidence interval for the incidence of awareness in this population is <1 in 300 (0.33%). CONCLUSION: Awareness under anesthesia is a distressing complication with a potential for long-term psychological consequences, and every effort should be undertaken to prevent it. It is reassuring though that our data in Indian cancer patients at high risk for intra-operative awareness suggests that it is an uncommon occurrence.