Grip Strength as a Simple Sarcopenia Screening for Postoperative Delirium Prediction After Lower Extremity Surgery in Elderly: Prospective Diagnostic Evaluation

초록

Background and Objectives: Grip strength (GS) decreases with age, serving as an indicators of sarcopenia, which is closely associated with frailty. These conditions aNect the prognosis of elderly patients, evident in postoperative delirium. While various methods exist to measure frailty or sarcopenia, many involve intricate criteria, making their routine application challenging in busy large-scale hospital settings. This challenge is particularly pronounced for patients undergoing lower limb surgeries, as their mobility is constrained, limiting the assessment. Therefore, this study aims to investigate whether GS, assessed simply and objectively screen sarcopenia, can independently predict postoperative delirium. Methods: We conducted a prospective, observational study in elderly patients, aged more than 65 years, and underwent lower extremity surgery. GS was measured before surgery following screening with the animal fluency test. Sarcopenia criteria were applied by 4 diNerent models including AWGS (Asian Working Group for Sarcopenia), European Working Group on Sarcopenia in Older people (EWGSOP2), Korea National Health and Nutrition Examination Survey (KNHANES) based sarcopenia and Simpler modified Fried frailty scale. Postoperative delirium was diagnosed by Confusion Assessment Method for the ICU (CAM-ICU). For the diagnostic usefulness of GS, sensitivity and specificity were compared through receiver operating characteristic (ROC) curves for delirium and decreased GS among the 4 diNerent models. Relationship between variables and outcomes was assessed by logistic regression analysis. Results: 150 patients median age of 73 years, 63.3% female, measured grip strength. Delirium was diagnosed in 17 patients (11.3%), among them, 13 patients showed decreased GS, and the ROC curves for delirium incidence among the 4 diNerent models revealed higher area under curve in AWGS (0.796) than other models. Among variables including age, ASA class, weight, intraoperative opioids, and pain scores at the postoperative care unit, only deceased GS (diagnosed with AWGS) was significant independent determinant of postoperative delirium with the odds ratio of 15.543 (95%CI, 4.647-51.989) (P<0.001) from multiple logistic regression analysis. Additional logistic regression analysis with law hand grip score instead of deceased GS revealed that delirium occurrence decreased by 9.4% for one-unit increase in GS with the odds of 0.906 (95%CI, 0.839-0.979) (P=0.013). Discussion and Conclusion: In our population, the definition of sarcopenia correlated the most with AWGS, and the degree of GS declination reflects the severity of frailty and the risk of delirium increases. Sarcopenia diagnosed simply by GS can be a predictive tool for the incidence of postoperative delirium in older adults undergoing lower extremity surgery.