双相正压通气与持续正压通气对急性呼吸窘迫综合征患者肺复张效果的比较

目的 比较双相正压通气(BIPAP)与持续正压通气(CPAP)对急性呼吸窘迫综合征(ARDS)患者肺复张的效果.方法 选择ARDS患者44例,ASA Ⅲ或Ⅳ级,性别不限,年龄35～63岁,体重52～74 kg,肺复张前基础通气模式为同步间歇指令通气联合压力支持通气,随机分为2组(n=22):CPAP组和BIPAP组.CPAP组10 s内逐渐上升呼气末正压(PEEP)至30 cm H2O,持续30 s,然后在5～10 8内恢复肺复张前通气模式.BIPAP组高水平和低水平压力分别为40、20 cm H2O,持续90 s,然后在5～10 s内恢复肺复张前通气模式.记录肺复张通气前即刻(T1),肺复张通气结束后即刻(T2)、2 min(T3)、5 min(T4)、15 min(T5)、30 min(T6)时HR、MAP、CVP、SpO2和肺动态顺应性(Cdyn).分别于T1、T5、肺复张通气结束后1 h(T7)、2 h(T8)、4 h(T9)时采集桡动脉血样,测定pH值、PaO2和PaCO2,计算PaO2/FiO2比值.结果 与CPAP组比较,BIPAP组SpO2、Cdyn、PaO2和PaO2/FiO2升高,CVP降低(P<0.05),HR和MAP比较差异无统计学意义(P>0.05).与T1时比较,CPAP组T3时MAP升高,T2时CVP升高,Cdyn降低,T3～6时SpO2和Cdyn升高,T7,8时PaO2升高,T5,7,8时PaO2/FiO2升高,BIPAP组T2～6时SpO2升高,T3～6时Cdyn升高,T5,7,8时PaO2和PaO2/FiO2升高(P<0.05).结论 与CPAP比较,BIPAP对ARDS患者行肺复张通气时血液动力学影响小,可进一步提高氧合和肺顺应性,是一种安全有效的肺复张方法 .

Comparison of recruitment maneuver efficacy of biphasic positive airway pressure and continuous positive airway pressure in patients with acute respiratory distress syndrome

Objective To compare the recruitment maneuver (RM) efficacy of biphasic positive airway pressure (BIPAP) and continuous positive airway pressure (CPAP) in patients with acute respiratory distress syndrome (ARDS).Methods Forty-four ASA Ⅲ or Ⅳ ARDS patients of both sexes aged 35-63 yr weighing 52-74 kg were randomly divided into 2 groups (n = 22 each): group CPAP and group BIPAP.The mode of synchronized intermittent mandatory ventilation and pressure support ventilation was applied before RMs.In group CPAP,positive end-expiratory pressure (PEEP) was gradually increased to 30 cm H2O in 10 s and maintained for 30 s,and the mode used before the RM was then recovered in 5-10 s.In BIPAP group,the high and low levels of PEEP were adjusted to 40 and 20 cm H2O respectively and maintained for 90 s,and then the mode used before the RM was recovered in 5-10 s.Pulmonary mechanics and bemadynamics were continuously observed.HR,MAP,CVP,SpO2and dynamic lung compliance (Cdyn) were recorded before the RM ventilation (T1),and at 0 min (T2),2 min (T3),5 min (T4),15 min (T5) and 30 min (T6) after the RM ventilation.Arterial blood samples were taken to determine pH value,PaO2and PaCO2at T1 ,T5 ,and at 1 h (T7),2 h (T8) and 4 h (T9) after the RM ventilation.PaO2/FiO2was calculated.Results Compared with group CPAP,SpO2,Cdyn,PaO2,and PaO2/FiO2were significantly increased,whereas CVP was significantly decreased in group BIPAP (P < 0.05),and no significant differences in HR and MAP were detected between group BIPAP and group CPAP ( P > 0.05).MAP at T3,CVP at T2,SpO2and Cdyn at T3-6,PaO2at T7,8 and PaO2/FiO2at T5,7,8 were significantly increased,whereas Cdyn at T2was significantly decreased in group CPAP,and SpO2at T2-6,Cdyn at T3-6,and PaO2and PaO2/FiO2at T5,7,8 were increased in group BIPAP as compared with the baseline at T1.Conclusion Application of BIPAP can further improve oxygenation and lung compliance with a stable hemedynamics,and it is a safe and effective recruitment maneuver and much better than CPAP in patients with ARDS.