Relationship between Postoperative Delirium and Intraoperative Expiratory Carbon Dioxide in Patients with Knee Arthroplasty

目的：评价膝关节置换术老年患者术后谵妄(POD)与术中呼气末二氧化碳(PetCO2)的关系。方法：选择邯郸市中心医院2023年10月至2024年10月全麻下行膝关节置换术老年患者100例，年龄 ≥ 65岁，性别不限，ASA分级I~III级，将所有患者根据PetCO2正常值，通过随机数方式分为三组：分别为低水平PetCO2组(L组，PetCO2 = 30~35 mmHg)，中水平PetCO2组(M组，PetCO2 = 35~45 mmHg)，高水平PetCO2组(H组，PetCO2 = 45~50 mmHg)，通过术中调控潮气量和呼吸频率使PetCO2维持在相应范围。术前1 d采用中文版3分钟谵妄诊断量表(3D-CAM)排除术前存在谵妄的患者。术后1 d、3 d、5 d每日一次采用3D-CAM量表评估POD发生情况。检测患者术前及术后1 d、3 d、5 d的S100-β蛋白及血浆神经元特异性烯醇化酶(neuron specific enolase, NSE)浓度。结果：最终纳入90例患者。谵妄发生18例，发生率为20%，谵妄发生情况为L组 > M组 > H组。术后1 d和术后3 d的S100-β蛋白水平存在组间差异，有统计学意义(P 2在一定范围内保持较高值可有效减少膝关节置换术老年患者术后POD的发生，从而缩短患者的住院时间，有助于节约医疗资源以及促进患者的快速康复。Objective: To evaluate the relationship between postoperative delirium (POD) and end-expiratory carbon dioxide (PetCO2) in elderly patients undergoing knee replacement. Methods: A total of 100 elderly patients with knee replacement under general anesthesia were selected from Handan Central Hospital from October 2023 to October 2024, aged ≥ 65 years old, with no gender limitation and ASA grades I to III. All patients were randomly divided into three groups by means of random numbers: low level PetCO2 group (Group L, Group L, group L, group L, group L, group L. PetCO2 = 30~35 mmHg), the medium-level PetCO2 group (group M, PetCO2 = 35~45 mmHg) and the high-level PetCO2 group (group H, PetCO2 = 45~50 mmHg) were maintained within the appropriate range through intraoperative regulation of tidal volume and respiratory rate. The Chinese version of 3-minute Delirium Diagnostic Scale (3D-CAM) was used to exclude patients with delirium 1 day before surgery. POD occurrence was assessed by 3D-CAM scale once a day at 1, 3 and 5 days after surgery. The concentrations of S100-β protein and plasma neuron specific enolase (NSE) were measured before and at 1, 3, and 5 days after surgery. Results: 90 patients were included. Delirium occurred in 18 cases, the incidence rate was 20%, delirium occurred in group L > group M > group H. There were significant differences in S100-β protein levels between groups 1 d and 3 d after surgery (P 2 in a certain range during operation can effectively reduce the occurrence of POD in elderly patients after knee replacement surgery, thus shortening the length of hospital stay of patients, helping to save medical resources and promote rapid recovery of patients.