Short-term memory impairment in patients undergoing general anesthesia and its contributing factors

Short-term memory disorder following surgery and anesthesia is a common complication of anesthesia and a common complaint of the patients.

This study was designed to assess memory impairment in patients undergoing elective surgery, investigate the effect of general anesthesia (GA) on memory, and identify the factors contributing to it, as well as the specific effect of anesthesia on each of the memory domains.

This cross-sectional study was performed in a university hospital.

Patients with the American Society of Anesthesiologists (ASA) Class I, II, and III who were candidates for elective abdominal surgery were enrolled. Patients answered several questions based on the Wechsler Memory Scale-Revised V (WMS-R-V), a standardized questionnaire, minutes before entering the operating room (OR) and again after 24 h postoperation, and the differences were recorded.

Analysis was performed using T-independent and Chi-square tests with Pearson's coefficient and Fischer's exact test and Man-Whitney test. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) software.

Four hundred patients (198 females and 202 males) with a mean age of 50.75 years were enrolled in our study. Our study results showed that short-term memory after GA was significantly decreased compared with preanesthesia (P < 0.05). There was no significant relationship between memory disorder following GA and gender (P = 0.18) or comorbidities (P = 0.138). However, older age was found to be a contributing factor to memory loss following GA (P < 0.001). The highest and lowest effect of GA were found on the number repeat (45.2%) and personal information (16.2%) domain of the memory.

GA significantly reduces the patient's short-term memory after the surgery.