保留自主呼吸喉罩全身麻醉对胸科手术患者脑血管二氧化碳反应性及术后早期认知功能的影响

Effects of maintaining spontaneous breathing with a laryngeal mask airway during general anesthesia on cerebrovascular CO2 reactivity and early postoperative cognitive function in thoracic surgery patients

摘要:

目的 评估保留自主呼吸喉罩全身麻醉在胸科手术中对脑血管二氧化碳反应性（CVR-CO₂）及术后早期认知功能的影响。方法 选取2021年8月—2023年3月南方医科大学顺德医院择期行胸科手术的患者80例，按照随机数字表法分成试验组与对照组，每组40例。试验组采用喉罩全身麻醉，术中保留自主呼吸；对照组采用双腔支气管插管全身麻醉，术中单肺机械通气。记录两组患者在麻醉诱导前（T₁）、建立人工气胸后10 min（T₂）、关胸前5 min（T₃）、手术结束时（T₄）采用经颅彩色多普勒超声检测技术测量大脑中动脉血流平均速度（V_MCA），同时行动脉血气分析，根据相关公式计算CVR-CO₂。并在术前1天、术后第1天、术后第7天记录两组患者的简易智力状态检查量表（MMSE）评分和早期术后认知功能障碍（POCD）发生率。结果 试验组与对照组组间Narcotrend值无差异（P >0.05），但在不同时间和变化趋势方面有差异（P <0.05）。试验组与对照组在T₁、T₂、T₃、T₄时的心率、平均动脉压、二氧化碳分压、V_MCA比较，不同时间点、组间及变化趋势均有差异（P <0.05）。两组在T₁～T₂时段、T₂～T₃时段、T₃～T₄时段大脑中动脉的血管反应性比较，不同时段、组间及变化趋势均有差异（P <0.05）。两组患者术前1天、术后第1天、术后第7天MMSE评分比较，不同时间、组间及变化趋势均有差异（P <0.05）。术后第1天对照组早期POCD发生率高于试验组（P <0.05）；术后第7天两组的早期POCD发生率无差异（P >0.05）；但试验组术后第7天MMSE评分仍高于对照组（P <0.05）。结论 在胸科手术中，与传统双腔支气管插管单肺机械通气全身麻醉比较，采用保留自主呼吸麻醉通气管理的患者大脑中动脉的流速增加，且CVR-CO₂更有优势，并能减少患者早期POCD的发生。

Abstract:

Objective To evaluate the effects of maintaining spontaneous breathing with a laryngeal mask airway (LMA) during general anesthesia on cerebrovascular carbon dioxide reactivity (CVR-CO₂) and early postoperative cognitive function in patients undergoing thoracic surgery.Methods Eighty patients scheduled for thoracic surgery from August 2021 to March 2023 were randomly divided into an experimental group and a control group (40 patients each). The experimental group received LMA general anesthesia with preserved spontaneous breathing, while the control group underwent double-lumen endotracheal tube intubation general anesthesia with single-lung mechanical ventilation. Cerebrovascular blood flow velocity (VMCA) was measured using transcranial color Doppler ultrasonography at different time points during the surgery. Blood gas analysis was performed to calculate CVR-CO₂. The Mini-Mental State Examination (MMSE) scores and the incidence of early postoperative cognitive dysfunction (POCD) were recorded preoperatively, on the first day, and on the seventh day postoperatively.Results Narcotrend values showed no difference between the experimental and control groups (P > 0.05). However, significant differences were observed in VMCA, heart rate, mean arterial pressure, and partial pressure of carbon dioxide at different time points and in their trends (P < 0.05). The cerebrovascular reactivity of the two groups differed significantly during various time intervals (P < 0.05). MMSE scores varied significantly at different time points between the two groups (P < 0.05). On the first postoperative day, the control group had a higher incidence of early POCD than the experimental group (P < 0.05). No significant difference in early POCD incidence was found on the seventh postoperative day (P > 0.05), but the experimental group had higher MMSE scores than the control group (P < 0.05).Conclusion In thoracic surgery, compared to traditional double-lumen endotracheal tube intubation with single-lung mechanical ventilation, maintaining spontaneous breathing with LMA anesthesia increases cerebral blood flow velocity and offers advantages in CVR-CO₂. Additionally, it reduces the incidence of early POCD.