影响甲型H1N1流感病毒性肺炎所致ARDS患者肺复张效果的因素探讨

Clinical factors influencing the efficacy of lung recruitment maneuver with high-level PEEP in patients with 2009 influenza A （ HIN1 ） -associated acute respiratory distress syndrome

目的 分析24例接受机械通气的甲型H1N1流感病毒性肺炎致ARDS患者的临床资料,探讨压力控制通气（PCV）联合间断高PEEP法肺复张的疗效及其影响因素.方法 以2009年10月至2010年2月中国医科大学附属第一医院急诊监护室（EICU）救治的24例接受机械通气的甲型H1N1流感病毒性肺炎所致ARDS患者为研究对象,均经口气管插管按照肺保护性通气策略应用PCV模式进行机械通气,当脉搏血氧饱和度（SpO2）持续低于88％超过30 min时,在原通气模式下增加PEEP至30 cmH2O（1 cmH2O =0.098 kPa）持续60 s进行肺复张,记录操作前、操作时、操作后30min内的呼吸机监测参数和患者平均动脉压、心率、SpO2等的变化,观察操作后SpO2最高值（SpO2max）、最低值（SpO2max）及其出现时间.复张操作后15 min内SpO2升高≥3％为复张有效.分析比较肺复张前后患者血流动力学和呼吸力学等指标.结果 24例患者中存活16例,死亡8例,在EICU接受机械通气时间3.5～12 d,中位数5.5d,期间肺复张操作158例次,有效76例次（48.1％）,存活组复张有效的比例与死亡组比较差异有统计学意义（66.2％ vs.33.3％,x2=16.91,P＜0.01）.与复张前比较,复张操作后患者心率增加（92.6±11.8）次/min vs.（73.O±12.6）次/min,t=2.12,P=0.038; MAP降低（66.1±9.3）mmHg vs.（73.9 ±11.4） mmHg（1 mmHg =0.133kPa）,t=1.98,P=0.049.85.9％的患者（134例次）复张操作后SpO2较操作前下降,SpO2min出现时间在复张操作后（2.1±0.6）min,有效组复张操作后SpO2 max较操作前增加（6.9±1.6）％,SpO2max出现时间在操作后（12.7±2.6）min.有效组肺复张操作后30 min SpO2较操作前增加（90.4±4.4）％vs.（86.7±7.6）％,t=2.01,P=0.047.有效组复张操作前平均PEEP水平低于无效组（8.6±3.4） cmH2Ovs.（11.3±4.2） cmH2O,t=2.24,P=0.028;平均机械通气时间短于无效组（4.1±3.1）d vs.（5.8±2.5）d,t=2.58,P=0.011;胸廓动态顺应性较高（30.8±6.2）mL/cmH2Ovs.（26.1±5.1）mL/cmH2O,t=2.12,P=0.038.结论 30 cmH2O的PEEP持续60 s肺复张方法可引起甲型H1N1流感病毒性肺炎所致ARDS患者短暂血流动力学改变,其效果可能与复张前PEEP水平、机械通气时间和胸廓动态顺应性有关.

Objective To investigate the clinical factors dominant in the efficacy of lung recruitment maneuver （RM） with high-level positive end-expiratory pressure （PEEP） under pressure control ventilation in patients with 2009 influenza A （H1N1）-associated acute respiratory distress syndrome （ARDS） by analyzing the clinical data of 24 patients treated with mechanical ventilation.Methods A retrospective study was carried out in a 16-bed capacity emergency intensive care unit （EICU） of the First Affiliated Hospital of China Medical University from October 2009 to January 2010.Twenty-four patients with influenza-associated ARDS were included.During pressure control ventilation,when SpO2 persisted lower than 88% for more than 30 min,RM with high-level PEEP was initiated to normalize lung volume at 30 cmH2O for 60 s.The RM was responded as SpO2 increased more than 3% within 15 min; otherwise,the increase below 3% in SpO2 would be considered non-responded.Variations in respiratory mechanics,oxygen metabolism and hemodynamic parameters were measured before and after RM.Results Of 24 patients with influenza-associated ARDS,16 survived and 8 deceased.The median duration of mechanical ventilation （DMV） in EICU was 5.5 days （range from 3.5 to 12.0 days）.During the entire study period,a total of 158 RMs with high-level PEEP were done,including 76 （48.1%） responded RMs （the responded group） and 82 （51.9%） non-responded RMs （the non-responded group）.In survivor group,the ratio of effective RM was higher than in nonsurvivors group （66.2% vs.33.3%,P 〈 0.01）.Compared with the data before RM,HR was increased （92.6 ± 11.8） vs.（73.0 ± 12.6）,P =0.038 and MAP was decreased （66.1 ±9.3） mmHg vs.（73.9 ± 11.4） mmHg,P=0.049 during RM,and these difference were not statistically significant at 3 min after RM.The decrease in SpO2 after 134 procedures of RMs in 85.9% patients,and the minimum value of SpO2 occurred at （2.1 ±0.6） min after RM.In the responded group,the maximum SpO2 were higher than that before RM by （6.9 ± 1.6） % occurred at （12.7 ±2.6） min after RM.Compared with the data before RM,SpO2 were increased （90.4 ± 4.4） % vs.（86.7 ± 7.6） %,P =0.047） in responded group at 30 min after RM.The initial PEEP level in the responded group was lower than that of the non-responded group （8.6 ± 3.4） cmH2O vs.（11.3 ±4.2） cmH2O,P=0.028.The initial mean DMV in the responded group was also shorter than that in the non-responded group （4.1 ± 3.1） d vs.（5.8 ± 2.5） d,P =0.011.Furthermore,the initial dynamic lung-thorax compliance （Cdyn） was obviously higher in the responded group than that in the non-responded group （30.8 ±6.2） mL/cmH2O vs.（26.1 ±5.1） mL/cmH2O,P=0.038.Conclusion The lung RM with high-level PEEP may cause temporary hemodynamic changes and the initial PEEP level,DMV,and Cdyn may be potential factors influencing the efficacy of lung RM.