INTRODUCTION
Currently similar to the world demographic structure, the population of Turkey is rapidly aging, and in 2023, it is estimated that the number of people over 65 will rise to 8.87 million (10.2% of the total population)1. Therefore, it can be predicted that anesthesiologists will have to deal more with elderly patients in the near future. Anesthesiologists encounter many problems in elderly patients, who have reduced efficacy of physiological functions. Postoperative pulmonary, cardiovascular, and renal complications are more likely to occur and adversely affect outcome in elderly patients2. In addition, postoperative cognitive dysfunction (POCD) is another frequent complication associated with increased morbidity, mortality, and reduced quality of life2,3.
Most POCD studies have focused on cardiac or non-cardiac major surgery, and the incidence or severity of POCD may vary depending on the type of surgery, cognitive assessment time, POCD definition, and neuropsychological testing tools4-8 . Cognitive decline is usually noticed by the patient’s family and can also be detected by comparison of preoperative and postoperative neuropsychological testing. Despite the importance of POCD, for elderly patients undergoing elective surgical procedures, evaluation of cognition is often overlooked9. There are few studies of POCD in minor surgical procedures and outpatient cases in elderly patients, although the minor surgeries accounts for a large proportion of the surgical burden10-12 . Certain negative features of the hospital environment, such as noise and preoperative anxiety, may impair cognitive functions in elderly patients, even in minor and outpatient surgeries10,11 .
The Mini Mental State Examination (MMSE) is a widely used cognitive assessment tool to detect POCD in multiple cognitive domains, including orientation, registration, attention and calculation, immediate recall, language, short-term memory, and construct ability. The time required for examination is 5–15 minutes, but it has high specificity and low sensitivity to detect mild cognitive impairment13-15 . On the other hand, the Montreal Cognitive Assessment (MoCA) is a new cognitive screening tool for multiple cognitive domains, including short-term memory, visuospatial skills, executive function, attention, concentration and working memory, language, and orientation. The MoCA has high sensitivity and specificity to detect patients with mild cognitive impairment performing in the normal range on the MMSE15-17.
In this prospective blinded observational study, we aimed to compare general and spinal anesthesia in terms of early postoperative cognitive decline and to determine the burden of this decline in elderly patients after elective minor surgery (inguinal herniorrhaphy). Our hypothesis was that the MoCA can detect more elderly patients with cognitive decline, even in the neuraxial anesthesia group.