Abstract:

 Objective To investigate the effect of different mechanical ventilation modes on cytokines in elderly patients undergoing abdominal surgery. Method Seventy-two cases of elderly patients （aged>65 years） who underwent abdominal surgery under general anesthesia were assigned to six groups（n=12）. Group A：VCV（Vt 6 ml/kg）+PEEP 8 mmHg+auto flow；group B：VCV（Vt 6 ml/ kg）+ PEEP 8 mmHg + const flow；group C：VCV（Vt 6 ml/kg）+ PEEP 12 mmHg + auto flow；group D： VCV（Vt 6 ml/kg）+ PEEP 12 mmHg+const flow；group E：VCV（Vt 10 ml/kg）+auto flow；group F：VCV （Vt 10 ml/kg）+ const flow. The six groups of patients with general anesthesia after tracheal intubation, were given VCV（Vt 6 ml/kg）+ const flow mode ventilation for 60 minutes, and then grouped according to the mode of ventilation, total ventilation time greater than 5 hours. The IL?8, IL?10, MMP?9, SP?A and SF concentrations were measured in venous blood and bronchoalveolar lavage fluid at two time points of 1 hours and 5 hours. Results Compared with the high tidal volume groups（group E, F ）and the low tidal volume groups（group A, B, C, D ）after 5 hours ventilation, the concentration of IL?8, MMP?9 in blood and BALF and the concentration of SP?A and SF in blood were increased significantly（P<0.05）, the concentration of IL-10 and SP?A in BALF and the concentration of IL-10 in blood were decreased significantly（P<0.05）. The concentration of IL-8 and MMP?9 in blood and BALF and the concentration of SF and SP?A in blood were higher in the F group than in the E group after 5 hours of ventilation （P<0.05）, while the concentration of SP-A in the BALF group was lower（P<0.05）. Conclusion Firstly, compared with low tidal volume mechanical ventilation, the high volume mechanical ventilation is more conducive to promoting the secretion of IL-8, MMP?9 and SF, inhibiting the release of IL?10, the decrease of SP?A in BALF, the increase of SP?A in blood, further intensify the degree of VILI. Secondly, in the elderly （aged>65 years） patients undergoing abdominal operation, the perioperative period of mechanical ventilation with VCV（Vt 6 ml/kg）+ PEEP 12 mmHg +auto flow mode is more conducive to reduce the acute inflammatory response and oxidative stress response, reduce the biological injury caused by mechanical ventilation, and reduce the degree of VILI.

Key words: mechanical ventilation mode, elderly abdominal surgery, cytokine, auto flow

摘要：

目的 探讨不同机械通气模式对于老年腹部手术患者细胞因子的影响。方法 72例择期进行腹部手术全麻机械通气的老年患者（年龄>65岁）分为6组，每组12例。A组：VCV（Vt6mL/kg）+PEEP8mmHg+auto?flow模式；B组：VCV（Vt6mL/kg）+PEEP8mmHg+const?flow模式；C组：VCV（Vt6mL/kg）+PEEP12mmHg+auto?flow模式；D组：VCV（Vt6mL/kg）+PEEP12mmHg+const?flow模式；E组：VCV（Vt10mL/kg）+auto?flow模式；F组：VCV（Vt10mL/kg）+const?flow模式。6组患者全身麻醉气管插管后，均予以VCV（Vt6mL/kg）+const?flow模式通气60min，再按分组的通气模式进行通气，总通气时间大于5h。在通气1h及5h两个时间点，抽取静脉血和支气管肺泡灌洗液检测IL?8、IL?10、MMP?9、SP?A以及SF浓度。结果 大潮气量组（E、F两组）较小潮气量四组（A、B、C、D四组）通气5h后，血与BALF中测定的IL?8、MMP?9浓度以及血中测定的SP?A、SF浓度明显升高（P<0.05），血与BALF中测定的IL?10浓度以及BALF中测定的SP?A浓度明显降低（P<0.05）。通气5h后F组较E组，血及BALF中IL?8以及MMP?9、血SF、血SP?A更高（P<0.05），而BALF中SP?A则更低（P<0.05）。结论 ①大潮气量机械通气较小潮气量机械通气而言，更有利于促进IL?8、MMP?9、SF的分泌，抑制IL?10的释放，BALF中SP?A下降，血中SP?A升高，进一步加剧了VILI的程度。②就老年（年龄>65岁）腹部手术患者而言，围手术期以VCV（Vt6mL/kg）+PEEP12mmHg+auto?flow模式机械通气较其他五种通气模式，更有利于减轻肺组织急性炎症反应及氧化应激反应的激活，减轻机械通气所致生物伤，从而减轻VILI的程度。

关键词: 机械通气模式, 自动变流, 老年腹部手术, 细胞因子