治疗性高碳酸血症对肺叶切除术患者单肺通气时的肺保护作用

Protective effect of therapeutic hypercapnia on lung during one-lung ventilation in patients undergoing pulmonary lobectomy

目的评价治疗性高碳酸血症对肺叶切除术患者单肺通气时的肺保护作用。方法择期拟行肺叶切除术患者50例，性别不限，年龄20—60岁，BMI18～30kg／m2，ASA分级Ⅱ级，采用随机数字表法，将其分为2组（n=25）：对照组（C组）和治疗性高碳酸血症组（H组）。全麻诱导气管插管后行容量控制通气，双肺通气时调整通气参数，维持P ET CO2 25～35mmHg，H组单肺通气期间吸入二氧化碳（3％-6％）-氧气（70％～82％）的混合气体，维持P ET ，CO2 50～60mmHg，C组吸入70％-88％氧气，维持P ET CO2 25—35mmHg。吸入七氟醚复合静脉输注瑞芬太尼维持麻醉。分别于单肺通气前即刻和恢复双肺通气30min时记录气道峰压、气道平台压和肺顺应性；采集动脉血样，进行血气分析，计算氧合指数，收集萎陷侧肺支气管肺泡灌洗液（BALF），并采集静脉血样，采用ELISA法测定BALF和血清TNF-α、IL-1β、IL-6、IL-8和IL-10的浓度。结果与C组比较，H组恢复双肺通气30min时气道峰压和气道平台压降低，肺顺应性升高，BALF中TNF-α、IL-1β、IL-6和IL-8的浓度降低，BALF中IL-10浓度升高（P〈0．05），氧合指数和血清炎症因子浓度比较差异无统计学意义（P〉0．05）。结论治疗性高碳酸血症虽然在改善肺叶切除术患者单肺通气时肺氧合功能方面无临床意义，但是可改善呼吸动力学和减轻炎症反应。

Objective To evaluate the protective effect of therapeutic hypercapnia on the lung during one-lung ventilation （OLV） in the patients undergoing pulmonary lobectomy. Methods Fifty patients of both sexes, aged 20-60 yr, with body mass index 18-30 kg/m2, of American Society of Anesthesiologists physical status Ⅱ , scheduled for elective pulmonary lobectomy, were randomly divided into 2 groups （n= 25 each） using a random number table： control group （group C） and therapeutic hypercapnia group （ group H）. After induction of general anesthesia, the patients were endotracheally intubated and mechanically ventilated in volume-controlled mode. The ventilator settings were adjusted during two-lung ventilation to maintain the end-tidal pressure of carbon dioxide （PETCO2） at 25-35 mmHg. Group H inhaled the mixture of CO2 （3%-6%） and 02 （70%-82%） during OLV to maintain P ET CO2 at 50-60 mmHg. Group C inhaled O2 （70%-88%） during OLV to maintain PET CO2 at 25-35 mmHg. Anesthesia was maintained with inhalation of sevoflurane and intravenous infusion of remifentanil. Immediately before OLV and at 30 min after restoration of two-lung ventilation, the airway peak pressure, airway plateau pressure and lung compliance were recorded, arterial blood samples were collected for blood gas analysis, and broncho-alveolar lavage fluid （BALF） from the collapsed lung and venous blood samples were collected for determination of tumor necrosis factor-alpha （TNF-α）, interleukin-lbeta （IL-1β）, IL-6, IL-8 and IL-10 concentrations in BALF and serum by enzyme-linked immunosorbent assay. Oxygenation index was calculated. Results Compared with group C, the airway peak pressure and airway plateau pressure were significantly decreased, the lung compliance was significantly increased, the concentrations of TNF-α, IL-1β, IL-6 and IL-8 in BALF were significantly decreased, and the concentrations of IL-10 in BALF were significantly increased at 30 min after restoration of two-lung ventilation （P〈0.05） , and no significant change was found in the oxygenation index and concentrations of inflammatory factors in serum in group H （P 〉 0.05 ）. Conclusion Therapeutic hypercapnia can improve pneumodynamics and attenuate inflammatory responses, and has no significant difference clinically in improving oxygenation during OLV in the patients undergoing pulmonary lobectomy.