高呼气末正压加肺复张治疗急性呼吸窘迫综合征

目的 评价高呼气末正压(PEEP)加肺复张(RM)治疗急性呼吸窘迫综合征(ARDS)的临床疗效和安全性.方法 选择2008年6月至2010年5月贵阳医学院附属医院内科重症监护病房(MICU)收治的ARDS患者38例,按信封法随机分为RM组和非RM组,每组19例.两组均采用压力支持通气(PSV)模式行机械通气,尽可能在吸入氧浓度(FiO2)＜0.60时达到目标氧合的最小PEEP水平,限制平台压≤30 cm H2O(1 cm H2O=0.098 kPa).RM时FiO2调至1.00,压力支持水平调至0,将PEEP升至40 cm H2O,持续30 s后再降低,8 h 1次,连续5 d.记录基础状态和5 d内的机械通气参数、血气分析结果及生命体征,比较两组氧合改善和肺损伤指标变化,观察RM的不良反应和气压伤发生率.结果 ①两组患者基础状态及机械通气参数均无明显差异.②两组动脉血氧分压(PaO2)和氧合指数(PaO2/FiO2)均明显改善,且RM组明显优于非RM组[PaO2(mm Hg,1 mm Hg=0.133 kPa)2 d:85.8±21.3比73.5±18.7,3 d:88.6±22.8比74.3±19.8,4 d:98.8±30.7比79.3±19.3,5 d:105.5±29.4比84.4±13.8;PaO2/FiO2(mm Hg)4 d:221.8±103.5比160.3±51.4,5 d:239.6±69.0比176.8±45.5,均P＜0.05].③两组呼出气冷凝液(EBC)中过氧化氢(H2O2)和白细胞介素-6(IL-6)水平均呈下降趋势,RM组下降幅度更明显[5 d时H2O2(μmol/L):0.04±0.02比0.10±0.03;IL-6(ng/L):4.12±2.09比9.26±3.47,均P＜0.05].④两组均无气压伤发生,心率无明显变化,无心律失常发生,中心静脉压和平均动脉压无明显变化.结论 高PEEP加RM可增加气体交换,改善氧合,减少呼吸机相关性肺损伤(VALI).应用RM比较安全,耐受性好,临床观察未见低氧血症、气压伤和血流动力学异常.

Abstract：

Objective To investigate the clinical effects and safety degree of high positive endexpiratory pressure (PEEP) combined with lung recruitment maneuver (RM) in patients with acute respiratory distress syndrome (ARDS). Methods Thirty-eight patients in medical intensive care unit (MICU) of Affiliated Hospital of Guiyang Medical College suffering from ARDS admitted from June 2008 to May 2010 were enrolled in the study. With the envelope method they were randomized into RM group and non-RM group, with n= 19 in each group. All patients received protective ventilation: pressure support ventilation (PSV) with plateau pressure limited at 30 cm H2O (1 cm H2O=0. 098 kPa) or lower. PEEP was set at the minimum level with fraction of inspired oxygen (FiO2) ＜0. 60 and partial pressure of arterial oxygen (PaO2) kept between 60 and 80 mm Hg (1 mm Hg=0. 133 kPa). RM was conducted by regulating FiO2 to 1.00, support pressure to 0, PEEP increased to 40 cm H2O and maintained for 30 seconds before lowering, and this maneuver was repeated every 8 hours for a total of 5 days. Base status, ventilation parameters, blood gas analysis and vital signs were obtained at baseline and for the next 5 days. Oxygenation status and lung injury indexes were compared between RM group and non-RM group, the adverse effects of (PaO2/FiO2) were both increased in RM group and non-RM group, but the values were higher in RM group [PaO2 (mm Hg) 2 days: 85.8± 21.3 vs. 73. 5± 18. 7, 3 days : 88. 6± 22. 8 vs. 74. 3 ±19. 8, 4 days : 98. 8 ±30. 7 vs. 79. 3±19. 3, 5 days: 105.5±29.4 vs. 84. 4±13. 8; PaO2/FiO2(mm Hg) 4 days: 221.8±103. 5 vs.interleukin-6 (IL-6) concentration in exhaled breath condensate (EBC) decreased in both groups but lower in RM group with significant difference [5 days H2O(μmol/L): 0. 04 ± 0. 02 vs. 0.10 ± 0.03 ; IL-6 (ng/L):No significant changes in heart rate were found during RM. Central venous pressure and mean arterial pressure remained unchanged after RM. Conclusion High level PEEP combined with RM can improve gas exchange and oxygenation, decrease ventilator associated lung injury (VALI). RM was safe and had good tolerance, no hypoxemia, barotrauma and hemodynamic instability were observed.

Effects of high positive end-expiratory pressure combined with recruitment maneuvers in patients with acute respiratory distress syndrome

Objective To investigate the clinical effects and safety degree of high positive endexpiratory pressure (PEEP) combined with lung recruitment maneuver (RM) in patients with acute respiratory distress syndrome (ARDS). Methods Thirty-eight patients in medical intensive care unit (MICU) of Affiliated Hospital of Guiyang Medical College suffering from ARDS admitted from June 2008 to May 2010 were enrolled in the study. With the envelope method they were randomized into RM group and non-RM group, with n= 19 in each group. All patients received protective ventilation: pressure support ventilation (PSV) with plateau pressure limited at 30 cm H2O (1 cm H2O=0. 098 kPa) or lower. PEEP was set at the minimum level with fraction of inspired oxygen (FiO2) ＜0. 60 and partial pressure of arterial oxygen (PaO2) kept between 60 and 80 mm Hg (1 mm Hg=0. 133 kPa). RM was conducted by regulating FiO2 to 1.00, support pressure to 0, PEEP increased to 40 cm H2O and maintained for 30 seconds before lowering, and this maneuver was repeated every 8 hours for a total of 5 days. Base status, ventilation parameters, blood gas analysis and vital signs were obtained at baseline and for the next 5 days. Oxygenation status and lung injury indexes were compared between RM group and non-RM group, the adverse effects of (PaO2/FiO2) were both increased in RM group and non-RM group, but the values were higher in RM group [PaO2 (mm Hg) 2 days: 85.8± 21.3 vs. 73. 5± 18. 7, 3 days : 88. 6± 22. 8 vs. 74. 3 ±19. 8, 4 days : 98. 8 ±30. 7 vs. 79. 3±19. 3, 5 days: 105.5±29.4 vs. 84. 4±13. 8; PaO2/FiO2(mm Hg) 4 days: 221.8±103. 5 vs.interleukin-6 (IL-6) concentration in exhaled breath condensate (EBC) decreased in both groups but lower in RM group with significant difference [5 days H2O(μmol/L): 0. 04 ± 0. 02 vs. 0.10 ± 0.03 ; IL-6 (ng/L):No significant changes in heart rate were found during RM. Central venous pressure and mean arterial pressure remained unchanged after RM. Conclusion High level PEEP combined with RM can improve gas exchange and oxygenation, decrease ventilator associated lung injury (VALI). RM was safe and had good tolerance, no hypoxemia, barotrauma and hemodynamic instability were observed.