床旁即时肺部超声结合压力-容积曲线设定PEEP对ARDS肺复张的临床评价

Clinical Evaluation of Point-of-care Lung Ultrasound Combined with Pressure-volume Curve to Titration Adjust PEEP for ARDS Lung Recruitment

目的探讨床旁即时肺部超声(POC-LUS)结合压力-容积(P-V)曲线个体化调节呼气末正压(PEEP)在急性呼吸窘迫综合征(ARDS)肺复张中的临床价值。方法对30例进行有创机械通气的ARDS患者进行研究,随机等分为超声再气化评分(US-RAS)指导PEEP设置的POC-LUS组和采用动脉血氧分压(PaO2)+动脉血二氧化碳分压(PaCO2)≥400 mmHg为依据调节PEEP的最大氧合法(Max-Oxy)组。两组均在机械通气开始时描记P-V曲线,分别采用呼气支最大曲率点(PMC)和吸气支低位拐点(LIP)设置初始PEEP。依据评估指标在第15 min、1 h、2 h、6 h、12 h、24 h、36 h及48 h的变化情况动态调整PEEP。同时记录各时间点患者的血气分析、呼吸力学等监护指标。结果两组患者基本情况差异均无统计学意义(P均>0.05),POC-LUS组与对照组初始PEEP值(11.2±0.9 cm H2O vs.8.4±1.8 cm H2O)差异有统计学意义(P<0.0001)。在施行肺复张过程中,POC-LUS组在第6 h的PaO2/FiO2(416.2±37.5)较前一时段升高(P<0.0001),此时调整得到的PEEP为(14.7±1.9)cm H2O,此后氧合逐渐好转。而Max-Oxy组的PaO2/FiO2在12 h(271.8±24.1)时才较前改善明显(P=0.0058),此时PEEP值为(13.5±1.3)cm H2O。两组各自确定的最佳PEEP值差异无统计学意义(P=0.0532),但POC-LUS组较Max-Oxy组提前6 h获得较好的肺复张效果(P均<0.05)。US-RAS与PaO2/FiO2呈负相关(r=-0.8725,R2=0.7613,P=0.0047)。研究中无不良事件发生。结论使用POC-LUS结合P-V曲线个体化滴定设置PEEP,有助于机械通气的ARDS患者较早地获得理想的肺复张效果,通过US-RAS调节PEEP改善ARDS患者氧合具有较好的提示意义。

Objective To investigate the clinical value of point-of-care lung ultrasound(POC-LUS)combined with pressure-volume(P-V)curve to individual titration positive end-expiratory pressure(PEEP)in lung recruitment of acute respiratory distress syndrome(ARDS).Method A study was conducted in 30 invasive mechanical ventilated ARDS patients,whom were randomly averaged into two groups according to different PEEP adjustment,that POC-LUS group guided by ultrasound re-aeration score(US-RAS) and maximum oxygenation (Max-Oxy) group based on PaO2+PaCO2≥400 mmHg.P-V curve was traced at the beginning of mechanical ventilation in both groups,and the initial PEEP was set by the point of maximum curvature(PMC)of the expiratory branch and the lower inflection point (LIP)of the inspiratory branch.Then the PEEP was adjusted dynamically according to indicators of each group at the 15 min,1 h,2 h,6 h,12 h,24 h,36 h and 48 h.At the same time,blood gas analysis,ventilator and other monitoring indexes were recorded.Result There was no significance in baseline characters between the two groups (P all>0.05).There was significant in the initial PEEP between POC-LUS group and the control group (11.2±0.9 cm H2O vs.8.4±1.8 cm H2O)(P<0.0001).During the study,the US-RAS of POC-LUS group showed the PEEP(14.7±1.9 cm H2O) obtained PaO2/FiO2(416.2±37.5)after 6 h of adjustment was significantly higher than before(P<0.0001),and then the oxygenation gradually improved.In group of Max-Oxy,PaO2/FiO2improved significantly(P=0.0058)at the 12 h(271.8±24.1),and the PEEP was(13.5±1.3) cm H2O.There was no significant difference in the optimal PEEP between the two groups(P=0.0532),but POC-LUS group had a better effect of lung recruitment 6 h earlier than Max-Oxy group(P all<0.05).US-RAS showed a good negative correlation with PaO2/FiO2(r=-0.8725,R2=0.7613,P=0.0047).No adverse events happened along the study.Conclusion Using of POC-LUS combined with P-V curve individualized titration adjust PEEP was helpful to obtain ideal lung recruitment earlier in mechanical ventilated ARDS patients,and US-RAS has a indicated significance in adjusting PEEP for improving ARDS oxygenation.