俯卧位机械通气治疗肺内/外源性急性呼吸窘迫综合征的比较研究

目的探讨俯卧位机械通气对肺内／外源性急性呼吸窘迫综合征（ARDS）的治疗作用。方法2001年1月-2004年2月华北煤碳医学院附属开滦医院重症监护治疗病房（ICU）收治42例ARDS患者，按ARDS病原不同分为肺内源性ARDS组（ARDSp）和肺外源性ARDS组（ARDSexp）。两组均早期予以俯卧位机械通气治疗。记录仰卧位及俯卧位2h和4h的动脉血气分析、呼吸频率（RR）、吸入氧浓度（FiO2）、氧合指数（PaO2／FiO2）、胸肺顺应性（C）、潮气量（VT）、气道阻力（Raw）的变化。5例患者进行了两种体位的胸部CT比较。结果俯卧位机械通气后，两组患者FiO2减少。RR减慢。PaO2／FiO2、动脉血氧饱和度（SaO2）、Raw均显著增加。ARDSexp组VT明显高于同时间点ARDSp组；而动脉血pH和动脉血二氧化碳分压（PaCO2）则无明显变化；ARDSp组与ARDSexp组同时间点比较，PaO2／FiO2显著增加；ARDSp组应用俯卧位机械通气改善氧合的有效率为65％，ARDSexp组为68％，二者比较差异无显著性；胸部CT显示俯卧位后原背侧渗出性改变有所改善。原腹侧正常肺组织出现渗出性改变。结论无论是ARDSp组还是ARDSexp组。俯卧位机械通气均能显著改善PaO2／FiO2，是ARDS患者早期支持治疗的重要而有效的手段。

Role of prone position mechanical ventilation in patients with acute respiratory distress syndrome originating from pulmonary disease and extra-pulmonary disease

Objective To assess the effect of mechanical ventilation on prone position for the treatment of acute respiratory distress syndrome (ARDS) originating from pulmonary disease and extrapulmonary disease. Methods From January 2001 to February 2004 in intensive care unit (ICU), 42 patients with ARDS were divided into pulmonary disease group and extrapulmonary disease group. All the patients were mechanically ventilated on prone position. Arterial blood gases, respiratory rate (RR), fraction of inspired oxygen(FiO_2), pulmonary compliance (C), tidal a volume (V_T), airway resistance (Raw) were measured before prone position and 2 hours and 4 hours after prone position. LungCT was measured in supine position and prone position. Results When patients were turned to prone position, SaO_2 and RR were decreased markedly in two groups. V_T was increased in extrapulmonary disease groups compared with pulmonary disease group at the same time. Oxygen index, hemoglobin oxygen saturation and Raw were increased markedly when patients were turned to prone position, and oxygen index of pulmonary disease group was higher than that of extrapulmonary disease group at the same time. No change was found in blood pH and partical pressure of carbon dioxide in artery (PaCO_2), but oxygenation was improved markedly in two groups. The effective rate of improved oxygenation was 65% in pulmonary disease group and 68% in extrapulmonary disease group, but no significant difference was found. Lung CT revealed that when the patients were in prone position, the degree of lung infiltration in the dorsal part of lung decreased while that in the ventral part increased. Conclusion Oxygenation is improved markedly in prone position in two groups. Mechanical ventilation on prone position was an effective method in the treatment of ARDS patients.