[Awareness with recall during general anesthesia: analysis of 2015 cases]

Abstract

Objective: To investigate the incidence of awareness with recall during general anesthesia in elective operation with modern anesthetic methods and to analyze the risk factors thereof.

Methods: 2025 patients, 1001 males and 1024 females, aged 53 +/- 16, underwent general anesthesia during different kinds of elective operation. Interview was conducted 1 - 3 days postoperatively to survey the incidence of awareness during operation. Two weeks later follow-up was conducted again to know if sequelae existed.

Results: Twenty-eight patients (1.4%) were identified as with awareness. Multiple regression analysis showed that awareness during operation was associated with being female (OR = 2.836, 95% CI = 1.81 - 6.810), use of laryngeal mask airway (LMA, OR = 19.609, 95% CI = 3.918 - 98.740), not use volatile anesthetics at a time or continuously during maintenance of anesthesia (OR = 3.084, 95% CI = 1.246 - 7.629), and intra-operative blood pressure fluctuation (OR = 10.430, 95% CI = 3.918 - 27.763), Premedicated patients had lower incidence of awareness during operation (OR = 0.326, 95% CI = 0.110 - 0.965). Twenty-three of the 28 patients with awareness during operation (82%) had auditory perception, 2 (7%) had both auditory and visual perception, 7 felt pain at different degrees, and 10 (36%) felt anxiety during operation. After effects appeared in 6 of the 28 patients (21%).

Conclusion: Awareness occurs in some patients undergoing elective operation. Being female, use of LMA, not using volatile anesthetics at a time or continuously during maintenance of anesthesia, and intra-operative blood pressure fluctuation are risk factors. Premedication may help prevent awareness during operation.