有创-无创序贯性机械通气治疗急性呼吸窘迫综合征的时机探讨

Study of timing of invasive and noninvasive sequential ventilation in patients with acute respiratory distress syndrome

目的 研究急性呼吸窘迫综合征（ARDS）患者早期拔除气管插管后序贯无创通气（NIV）的时机及价值.方法 采用前瞻性随机对照研究方法,选取2012年1月至2013年11月新疆医科大学第一附属医院呼吸重症医学科（RICU）收治的外科疾病所致ARDS患者为研究对象.按随机数字表法将患者分为序贯组和对照组,并且均行气管插管机械通气,前3d每12h进行1次肺复张,采用压力控制通气（PCV）,之后选择同步间歇指令通气（SIMV）＋压力支持通气（PSV）＋呼气末正压（PEEP）或辅助/控制通气（A/C）.序贯组当患者氧合指数（PaO2/FiO2）在200 ～ 250 mmHg（1 mmHg=0.133 kPa,PEEP为8 cmH2O,支持压力为12 cmH2O,1 cmH2O=0.098 kPa）,且胸部影像学提示肺部急性渗出阴影部分吸收时,拔除气管内插管序贯NIV;对照组持续行气管内插管或气管切开机械通气,直至脱机.记录两组基线资料及序贯组二次气管插管率,并比较两组有创通气时间、总机械通气时间、ICU住院时间、呼吸机相关性肺炎（VAP）发生率和病死率.结果 53例ARDS患者人选,其中序贯组26例,对照组27例.序贯组气管内插管时间为7.0（6.8,9.5）d,二次气管插管发生率为7.7％（2/26）.序贯组拔管前自主呼吸试验（SBT≤10 min）时患者呼吸和循环指标均较SBT前有明显差异,说明此时拔管序贯NIV仍在早期.序贯通气后除1h时呼吸频率有短暂增加外,呼吸和循环指标与对照组均无明显差异,说明序贯NIV可以延续有创通气的功能.序贯组与对照组有创机械通气时间[d：7.0（6.8,9.5）比21.0（17.0,25.0）,Z=-6.048,P=0.000]、总机械通气时间（d：18.0±4.1比22.0±7.3,t=-2.805,P=0.008）和ICU住院时间（d：21.0±4.1比28.0±8.1,t=-4.012,P=0.000）差异均有统计学意义,而VAP发生率[15.4％（4/26）比29.6％（8/27）,Х^2=1.535,P=0.215]和病死率[7.7％（2/26）比18.5％（5/27）,P=0.420]差异均无统计学意义.结论 外科疾病所致ARDS病例在较低机械通气条件下,PaOdFiO2达到200～250 mmHg时序贯无创通气方法可早期脱机,并可缩短有创机械通气时间、总机械通气时间和RICU住院时间.

Objective To investigate the timing and value of noninvasive ventilation （NIV） as a weaning tool immediately after early extubation in patients with acute respiratory distress syndrome （ARDS）.Methods A prospective randomized controlled trial was conducted.The ARDS patients with surgical diseases admitted to Department of Respiratory Intensive Care Unit （RICU） of the First Affiliated Hospital of Xinjiang Medical University were enrolled.The patients were randomly divided into sequential group and control group.All patients underwent endotracheal intubation and were mechanically ventilated.Every 12 hours during the first 3 days,the lung recruitment maneuver was performed during pressure control ventilation （PCV）.After lung recruitment,all patients were ventilated with synchronized intermittent mandatory ventilation （SIMV） ＋ pressure support ventilation （PSV） ＋ positive end-expiratory pressure （PEEP） or assistant/control ventilation （A/C）.The objects in sequential group who met the following criteria including those with oxygen index （PaO2/FiO2） reaching 200-250 mmHg （1 mmHg=0.133 kPa） under PEEP of 8 cmH2O （1 cmH2O =0.098 kPa）,and pressure support of 12 cmH2O,and most acute infiltrating lesions having resolved on chest imaging,received noninvasive ventilation （NIV） immediately after extubation,and patients in control group continued to have invasive mechanical ventilation via intubation or tracheostomy with an endotracheal tube.The baseline data in both groups and the number of re-intubation in the sequential group were recorded.The duration of invasive mechanical ventilation and total duration of mechanical ventilation,ICU length of stay,the incidence of ventilator-associated pneumonia （VAP）,and mortality rate were compared between the two groups.Results 53 consecutive adult patients were enrolled,including 26 in sequential group and 27 cases in control group.The period of endotracheal intubation was 7.0 （6.8,9.5） days,and 7.7% （2/26） patients underwent re-intubation in sequential group.There were significant difference in respiratory and circulatory indicators before extubation spontaneous breathing trial （SBT） ≤10 minutes in sequential group,indicating that the patients were still in the early stage of extubation sequential NIV.There was no significant difference in indices reflecting respiratory function and circulation between the two groups,except that respiratory rate at 1 hour was slightly increased in sequential group as compared with that of control group,indicating that sequential NIV could maintain invasive ventilation function.There was significant difference in duration of invasive mechanical ventilation [days：7.0 （6.8,9.5） vs.21.0 （17.0,25.0）,Z=-6.048,P=0.000],duration of total mechanical ventilation （days：18.0 ± 4.1 vs.22.0 ± 7.3,t=-2.805,P=0.008）,and length of ICU stay （days：21.0 ± 4.1 vs.28.0 ± 8.1,t=-4.012,P=0.000） between sequential group and control group,but there was no significant differences in the incidence of VAP [15.4% （4/26） vs.29.6 （8/27）,Х^2=1.535,P=0.215] and mortality rate [7.7% （2/26） vs.18.5% （5/27）,P=0.420].Conclusion When PaO2/FiO2 reached 200-250 mmHg under the condition of low ventilation,sequential NIV facilitates the early discontinuation of mechanical ventilation in ARDS patients with surgical diseases,with shortening of duration of invasive mechanical ventilation,total mechanical ventilation,and the length of ICU stay.