选择性脑降温对脊柱外科内固定术老年患者术后血脑屏障功能及谵妄发生的影响

Effects of selective brain cooling on postoperative blood-brain barrier dysfunction and delirium in the elderly patients undergoing spinal fixation surgery

摘要:

目的 探讨选择性脑降温对老年脊柱外科内固定患者术后血脑屏障功能及谵妄发生的影响。方法 选取2022年5月—2023年7月在武汉市第四医院静吸复合全身麻醉下行脊柱外科内固定术的患者126例。采用简单随机分组法将患者分为选择性脑降温组（SBC组）和对照组（C组）。两组患者均采用液体加温联合体表加温毯，保持加温直至手术结束，SBC组患者使用设定温度为4 ℃的电子冰帽进行选择性脑降温。分别于麻醉诱导前（T₀）、麻醉诱导后30 min（T₁）、60 min（T₂）、90 min（T₃）、120 min（T₄）、150 min（T₅）、术毕（T₆）和出麻醉恢复室（PACU）（T₇）时记录患者鼻咽温、肛温，于T₆时从患者肘正中静脉抽取患者外周静脉血样，采用免疫磁珠法分离鉴定脑微血管内皮细胞（BMECs），荧光显微镜下计数细胞；术前1天、术后第1天及术后第3天分别采用散射比浊法及酶联免疫吸附试验测定外周血C反应蛋白（CRP）、S100β蛋白浓度；手术后第1～3天同时采用3分钟谵妄诊断量表和谵妄评估量表-98修订版量表（DRS-R-98）评估患者术后谵妄（POD）的发生情况。结果 两组患者性别构成、年龄、体重、文化程度比例、高血压病史率、心脏病史率、糖尿病史率、美国麻醉师协会分级Ⅲ级率、术中低血压、手术持续时间、输液量、失血量、自体血回输量、常规抗菌药物使用率比较，经χ² / t检验，差异均无统计学意义（P >0.05）。SBC组T₆时静脉血BMECs计数、POD率均低于对照组（P <0.05）。两组患者气管拔管所需时间、热舒适度评分、PACU滞留时间、总住院时间、术后恢复质量量表评分、PACU寒颤率、术后躁动率、术后发热率比较，经t / χ²检验，差异均无统计学意义（P >0.05）。两组患者T₁～T₇时肛温比较，经重复测量设计的方差分析，结果 ①不同时间点间的肛温比较，差异有统计学意义（P <0.05）；②两组患者肛温比较，差异有统计学意义（P <0.05）；③两组患者肛温变化趋势比较，差异有统计学意义（P <0.05）。两组患者术前、术后1 d、术后3 d血清CRP、S100β浓度比较，经重复测量设计的方差分析，结果 ①不同时间点间血清CRP、S100β浓度比较，差异均有统计学意义（P <0.05）；②两组患者血清CRP、S100β浓度比较，差异均有统计学意义（P <0.05）；③两组患者血清CRP、S100β浓度变化趋势比较，差异均有统计学意义（P <0.05）。两组患者术后第1天、术后第2天及术后第3天DRS-R-98评分比较，经重复测量设计的方差分析，结果 ①不同时间点间的DRS-R-98评分比较，差异有统计学意义（P <0.05）；②两组患者DRS-R-98评分比较，差异有统计学意义（P <0.05）；③两组患者DRS-R-98评分变化趋势比较，差异有统计学意义（P <0.05）。SBC组POD总发生率低于对照组（P <0.05）。结论 选择性脑降温能安全降低行脊柱外科内固定老年患者术中脑局部温度，维持患者血脑屏障结构和功能的稳定，降低患者POD的发生风险。

Abstract:

Objective To evaluate the effects of selective brain cooling on postoperative blood-brain barrier dysfunction and delirium in the elderly patients undergoing spinal fixation surgery.Methods A total of 126 patients undergoing spinal fixation surgery under combined intravenous-inhalational anesthesia in our hospital from May 2022 to July 2023 were selected, and they were divided into the selective brain cooling group (group SBC) and the control group (group C) by simple randomization. Warming was maintained using the fluid warmers combined with the warming blankets until the end of the operation in both groups. In the SBC group, selective brain cooling was performed through electronic ice caps with a set temperature of 4 ℃. Nasopharynx temperature and rectal temperature were recorded before anesthesia induction (T₀), 30 min (T₁), 60 min (T₂), 90 min (T₃), 120 min (T₄), and 150 min (T₅) after anesthesia induction, at the end of the operation (T₆) and when leaving the post-anesthesia care unit (PACU) (T₇). Blood samples were collected via the median cubital vein at T₆, brain microvascular endothelial cells (BMECs) were isolated and identified by immunomagnetic beads, and the target cells were counted under fluorescence microscope. The concentrations of C-reactive protein (CRP) and S100β in peripheral blood were measured by rate nephelometry and enzyme-linked immunosorbent assay respectively 1 day before surgery, and 1 day and 3 days after surgery. Both 3D-CAM and DRS-R-98 scales were used to assess the incidence of postoperative delirium (POD) in patients 1 day to 3 days after surgery.Results There was no difference in sex composition, age, body weight, degree of education, percentages of history of hypertension, cardiac diseases and diabetes mellitus, the percentage of ASA grade III, incidence of intraoperative hypotension, operative duration, volume of infused fluids, blood loss volume, volume of autotransfusion, or the usage rate of conventional antibiotics as analyzed by chi-square or t test (P > 0.05). The count of BMECs in venous blood and the incidence of POD in the SBC group were lower than those in the C group at T₆ (P < 0.05). The time to tracheal extubation, thermal comfort scores, duration of PACU stay, length of hospital stay, Quality of Recovery-40 Questionnaire (QoR-40) scores, and incidences of chills during PACU stay, postoperative agitation, and postoperative fever were not different between the two groups as analyzed by chi-square or t test (P > 0.05). The rectal temperature at T₁ to T₇ between the SBC group and the C group was compared via the repeated measures analysis of variance, and the results revealed that comparison of rectal temperature at different time points showed a statistically significant difference (P < 0.05), comparison of rectal temperature between the SBC group and the C group showed a statistically significant difference (P < 0.05), and that comparison of the change trends of rectal temperature between the SBC group and the C group showed a statistically significant difference (P < 0.05). The serum concentrations of CRP and S100β in the SBC group and the C group before, 1 d after and 3 d after surgery were compared, which showed that they were different among the time points (P < 0.05) and between the groups (P < 0.05), and that the change trends of the serum concentrations of CRP and S100β were different between the groups (P < 0.05). The DRS-R-98 scores were compared between the SBC group and the C group at 1 d, 2 d and 3 d after surgery, and the results demonstrated that they were different among the time points (P < 0.05) and between the groups (P < 0.05), and that the change trends of DRS-R-98 scores were different between the SBC group and the C group (P < 0.05). The overall incidence of POD in the SBC group was lower than that in the C group (P < 0.05).Conclusions Selective brain cooling can lower the brain temperature locally in a safe manner, maintain the stability of the blood-brain barrier structure and function, and reduce the risk of POD in elderly patients undergoing spinal fixation surgery.