Cognitive dysfunction in older patients undergoing orthopedic surgery: Analysis of demographic, Clinical, and intraoperative risk factors

Abstract

Objective: We evaluated cognitive dysfunction in older patients undergoing orthopedic surgery regarding demographic, clinical, and intraoperative risk factors. Methods: A total of 56 older patients (aged >65 years, mean ± SD age: 75.1±6.8 years, 75% were females) hospitalized for elective orthopedic surgery were included. Data on patient demographics (age, gender), comorbid diseases, planned surgery indications, American Society of Anesthesiologists (ASA) Classification category, intraoperative time (min), intraoperative blood loss (mL), and length of hospital stay (LOS; days) were recorded for each patient. Vital signs were recorded thrice, preoperatively, intraoperatively (every 15 min), and postoperatively (first hour), whereas pain was assessed based on visual analog scale (VAS) scores in the postoperative period (1st h, 12th h, 36th h). The Mini-Mental State Examination (MMSE) was administered preoperatively and in the postoperative 72nd h to assess cognitive status. Results: Overall, a significant decrease was noted in MMSE scores from the preoperative to postoperative (72nd h) period [median (minimum-maximum) 26 (12-30) vs. 23.5 (12-30), p<0.001]. The significant decline in MMSE scores after the operation was evident in each subgroup, regardless of the gender, ASA category, presence of comorbidity, or acute renal failure (average SD change from baseline ranged from -1.5 to -1.0; p-values ranged from 0.024 to <0.001). Preoperative and postoperative MMSE scores were negatively correlated with age (r=0.415, p=0.002 and r=-0.406, p=0.003, respectively) and intraoperative time (r=-0.511, p<0.001 and r=-0.428, p=0.002, respectively). Conclusion: Our findings revealed the likelihood of postoperative cognitive dysfunction in older patients undergoing orthopedic surgery, regardless of gender, comorbidities, or ASA category. However, there was an increased risk of postoperative cognitive decline with increased patient age and longer intraoperative time.