关键词: 机械通气模式, 自动变流, 老年腹部手术, 细胞因子

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