体外膜肺氧合支持下甲型H1N1流感的肺保护策略探讨

The lung protection strategy under the support of extracorporeal membrane oxygenation in patients suffering from influenza A H1N 1

目的观察体外膜肺氧合（ECMO）用于甲型H1N1流感所致重症肺炎时，如何通过肺休息实施肺保护策略。方法对5例甲型H1N1流感所致重症肺炎患者应用ECMO支持和不同机械通气策略进行治疗。其中2例死亡患者均采用同步间歇指令通气（SIMV）及双水平气道正压（BiPAP）通气模式，同时利用气道压力释放通气（APRV）模式进行控制性肺膨胀，复张压力设定在40cmH2O（1cmH2O=0．098kPa）。3例存活患者均应用肺休息策略，即逐渐抬高呼气末正压（PEEP），通过最佳顺应性寻找最佳PEEP，然后通过BiPAP模式将高水平压力（Phigh）设定为20cmH2O进行观察。结果死亡2例，其中1例因肺损伤反复出现自发性气胸伴脓毒症死亡；另1例死于多器官功能障碍综合征。3例采用肺休息治疗策略，最终康复。结论甲型H1N1流感所致重症肺炎患者应用ECMO治疗时，通过肺休息实施肺保护策略，可以明显改善预后，减少肺损伤的发生。

Objective To study the effect of extracorporeal membrane oxygenation （ECMO） in patients suffering from severe pneumonia complicating influenza A H1N1 by putting lungs in rest to protect the latter. Methods Five patients with severe pneumonia following influenza A H1N1 were treated with ECMO and different modes of mechanical ventilation at the same time. Two patients died, both of them received synchronized intermittent mandatory ventilation （SIMV） and bi-level positive airway pressure （BiPAP） modes, with airway pressure release ventilation （APRV） to control lung expansion with expansion pressure 40 cm H2O （1 cm H2O=0. 098 kPa）. In 3 survivors, the strategy of lung rest was performed by giving an optimized positive end expiratory pressure （PEEP） with an optimal compliance by gradually elevation of PEEP, and high-level pressure （Phigh） at 20 cm H2O by application of BiPAP mode. Results One patient died due to lung damage and repeated spontaneous pneumothorax and sepsis ; 1 patient died due to multiple organ dysfunction syndrome. Three patients recovered after following the strategy of lung rest. Conclusion When ECMO is used for severe pneumonia complicating influenza A H1N1, prognosis can be obviously improved, with decrease in the occurrence of lung damage through the protection strategy of lung rest.