论文部分内容阅读
目的探讨新的氧合指数即结合了平均气道压(P■)的[PaO2/(FiO2×P■)]能否较传统氧合指数(PaO2/FiO2)更准确地反映急性呼吸窘迫综合征(ARDS)患者的肺内分流(Qsp/Qt)。方法符合ARDS诊断标准的患者12例,气管插管呼吸机支持,采用肺保护性通气策略(潮气量6 mL/kg,呼吸频率16次/min,FiO260%),留置Swan-Ganz导管,采用低流速法测定准静态肺压力-容积曲线,确定低位转折点压力(Pinf)。调整PEEP水平,观察血流动力学、呼吸力学的变化,分别留取外周及肺动脉血行血气分析,计算Qsp/Qt和PaO2/FiO2。结果递增的呼气末正压(PEEP)不足以显著改变ARDS患者的肺顺应性(Cst)、PaO2/FiO2及PaO2/(FiO2×P■)(P>0.05)。递增的PEEP对Qsp/Qt改变不明显(P>0.05)。检验Qsp/Qt与PaO2/(FiO2×P■)及Qsp/Qt与PaO2/FiO2的相关系数,Δz=0.571,无显著性差异(P>0.05)。影响ARDS患者的Qsp/Qt和PaO2/FiO2的参数不是Paw,而是Cst。结论 PaO2/(FiO2×Paw)与PaO2/FiO2相比,两者对ARDS患者肺内分流的评估价值相当。
Objective To investigate whether the new oxygenation index (PaO2 / (FiO2 × P)) combined with the mean airway pressure (P ■) can more accurately reflect the acute respiratory distress syndrome than the traditional oxygenation index (PaO2 / FiO2) (ARDS) patients with intrapulmonary shunt (Qsp / Qt). Methods 12 patients with ARDS criteria were supported by endotracheal intubation ventilator. The protective ventilation strategy (tidal volume 6 mL / kg, respiratory rate 16 / min, FiO2 60%) was used. Swan-Ganz catheter was used and low Flow velocity method to determine quasi-static lung pressure-volume curve to determine the low turning point pressure (Pinf). The level of PEEP was adjusted to observe changes of hemodynamics and respiration mechanics. Peripheral blood samples and pulmonary artery blood samples were collected for blood gas analysis and Qsp / Qt and PaO2 / FiO2 were calculated. Increasing positive end-expiratory pressure (PEEP) was not sufficient to significantly alter lung compliance (Cst), PaO2 / FiO2 and PaO2 / (FiO2 × P ■) in patients with ARDS (P> 0.05). Increasing PEEP did not change Qsp / Qt significantly (P> 0.05). The correlation coefficient between Qsp / Qt and PaO2 / (FiO2 × P ■) and Qsp / Qt and PaO2 / FiO2 was tested, Δz = 0.571, no significant difference (P> 0.05). The parameters of Qsp / Qt and PaO2 / FiO2 affecting ARDS patients are not Paw but Cst. Conclusions PaO2 / (FiO2 × Paw) is comparable to PaO2 / FiO2 in assessing intrapulmonary shunts in patients with ARDS.