控制性肺膨胀对急性肺损伤患者肺气体交换及氧代谢的影响

Effect of sustained inflation on pulmonary gas exchange and oxygen metabolism in patients with acute lung injury

目的 通过观察控制性肺膨胀 (SI)同小潮气量通气模式结合对急性肺损伤 (ALI)患者肺气体交换及氧代谢的影响 ,探讨SI的疗效及其最佳压力值。方法 选择严重创伤并发ALI的患者 31例 ,确诊ALI后 2 4h内入重症监护室 (ICU)予机械通气治疗。先予小潮气量通气模式 (基础阶段 )通气 1h ,然后分别给予 2 0cmH2 O× 30s(SI1 )、30cmH2 O× 30s(SI2 )、40cmH2 O× 30s(SI3)、50cmH2 O× 30s(SI4 )的SI各通气 1h ,在基础通气 1h、SI后 1h以及回到基础通气 1h各时点监测肺气体交换及氧代谢指标。结果 与基础通气模式相比 ,SI1 及SI2 后各指标无明显变化 ,SI3和SI4 后氧分压 (PaO2 )显著提高 ,分别由(92 0± 1 4 2 )mmHg上升至 (1 2 1 3± 1 6 9)mmHg和 (1 2 0 4± 1 7 0 )mmHg ,P <0 0 1 ,氧输送指数 (DO2 I)也显著提高 ,肺内分流率(Qs/Qt)显著减少 ,而当SI结束后 ,所有数据均回到基础通气状态。并且我们发现SI3和SI4 对氧合的改善作用无显著性差异。结论 SI同小潮气量通气模式结合治疗ALI患者时 ,可显著改善肺气体交换及氧合功能。 40cmH2

Objective To observe the influence of sustained inflation(SI)combined with small tidal volume ventilation on pulmonary gas exchange and oxygen metabolism in patients with acute lung injury(ALI),and to investigate the effects of SI and the best pressure of SI.Methods 31 patients with severe trauma followed by acute lung injury were selected for this study.All patients were admitted to the intensive care unit(ICU)within 24 hours after ALI diagnoses and were mechanically ventilated.Firstly they underwent 1 h of small tidal volume ventilation(baseline) and then 1 h of SI with 20 cmH 2O×30 s(SI 1),30 cmH 2O×30 s(SI 2),40 cmH 2O× 30 s(SI 3),50 cmH 2O×30 s (SI 4)respectively.Parameters of pulmonary gas exchange and oxygen metabolism were measured at 1 h of baseline?1 h of SI and 1 h of returning baseline.Results All the parameters indicated that there were no significant differences after SI 1 and SI 2 compared with baseline,but PaO 2 increased significantly after SI 3 and SI 4〔from(92 0±14 2)mmHg to (121 3±16 9)mmHg and (120 4±17 0)mmHg respectively, P <0 01〕.After SI 3 and SI 4 oxygen delivery index(DO 2I)increased significantly,pulmonary venous mixture(Qs/Qt)decreased significantly.After SI interruption,all the physiological variables returned to baseline.We found that there were no significant difference in improvement of oxygenation between SI 3 and SI 4.Conclusions Treatment of SI combined with small tidal volume ventilation for the patients with acute lung injury could improve pulmonary gas exchange and oxygenation.40 cmH 2O was the best pressure of SI.