Expiratory flow limitation(EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety...Expiratory flow limitation(EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety of intensive care unit conditions. Recent evidence suggests that the presence of EFL is associated with an increase in mortality, at least in acute respiratory distress syndrome(ARDS) patients, and in pulmonary complications in patients undergoing surgery. EFL is a major cause of intrinsic positive end-expiratory pressure(PEEPi), which in ARDS patients is heterogeneously distributed, with a consequent increase of ventilation/perfusion mismatch and reduction of arterial oxygenation. Airway collapse is frequently concomitant to the presence of EFL.When airways close and reopen during tidal ventilation, abnormally high stresses are generated that can damage the bronchiolar epithelium and uncouple small airways from the alveolar septa, possibly generating the small airways abnormalities detected at autopsy in ARDS. Finally, the high stresses and airway distortion generated downstream the choke points may contribute to parenchymal injury, but this possibility is still unproven. PEEP application can abolish EFL, decrease PEEPi heterogeneity, and limit recruitment/derecruitment.Whether increasing PEEP up to EFL disappearance is a useful criterion for PEEP titration can only be determined by future studies.展开更多
目的 探讨肺复张治疗急性A型主动脉夹层(acute type A aortic dissection,ATAAD)术后低氧血症的疗效及安全性。方法 选取2019年11月至2022年5月广西医科大学第一附属医院ATAAD术后低氧血症患者56例,将其随机分为肺复张组(n=36)及常规治...目的 探讨肺复张治疗急性A型主动脉夹层(acute type A aortic dissection,ATAAD)术后低氧血症的疗效及安全性。方法 选取2019年11月至2022年5月广西医科大学第一附属医院ATAAD术后低氧血症患者56例,将其随机分为肺复张组(n=36)及常规治疗组(n=20)。常规治疗组患者在肺保护性通气基础上行常规机械通气,肺复张组患者采用呼气末正压通气(positive end expiratory pressure,PEEP)递增法进行肺复张。比较两组患者治疗前后的动脉血气分析、呼吸力学指标、血流动力学指标和血清白细胞介素(interleukin,IL)-6及IL-10水平。结果 治疗后12h、24h,两组患者的动脉血氧分压(arterial partial pressure of oxygen,PaO_(2))、氧合指数(oxygenation index,OI)、肺静态顺应性(C_(stat))及肺动态顺应性(C_(dyn))均显著高于本组治疗前,肺泡动脉氧分压差[PO_(2)(A-a)]、呼吸指数(respiratory index,RI)、气道峰压(P_(peak))及气道平台压(P_(plat))均显著低于本组治疗前(P<0.05);肺复张组患者的PaO_(2)、OI、C_(stat)及C_(dyn)均显著高于常规治疗组,PO_(2)(A-a)、RI、P_(peak)及P_(plat)均显著低于常规治疗组(P<0.05)。肺复张组患者肺复张过程中收缩压及平均动脉压有所下降(P<0.05),中心静脉压有所升高(P<0.05),肺复张结束后均恢复至基线水平。治疗后12h,两组患者的血清IL-6和IL-10水平均显著低于本组治疗前(P<0.05)。结论 PEEP递增法肺复张可改善ATAAD术后低氧血症患者的氧合及肺顺应性,但对血流动力学存在一过性影响,治疗时应进行严密监测。展开更多
文摘Expiratory flow limitation(EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety of intensive care unit conditions. Recent evidence suggests that the presence of EFL is associated with an increase in mortality, at least in acute respiratory distress syndrome(ARDS) patients, and in pulmonary complications in patients undergoing surgery. EFL is a major cause of intrinsic positive end-expiratory pressure(PEEPi), which in ARDS patients is heterogeneously distributed, with a consequent increase of ventilation/perfusion mismatch and reduction of arterial oxygenation. Airway collapse is frequently concomitant to the presence of EFL.When airways close and reopen during tidal ventilation, abnormally high stresses are generated that can damage the bronchiolar epithelium and uncouple small airways from the alveolar septa, possibly generating the small airways abnormalities detected at autopsy in ARDS. Finally, the high stresses and airway distortion generated downstream the choke points may contribute to parenchymal injury, but this possibility is still unproven. PEEP application can abolish EFL, decrease PEEPi heterogeneity, and limit recruitment/derecruitment.Whether increasing PEEP up to EFL disappearance is a useful criterion for PEEP titration can only be determined by future studies.
文摘目的 探讨肺复张治疗急性A型主动脉夹层(acute type A aortic dissection,ATAAD)术后低氧血症的疗效及安全性。方法 选取2019年11月至2022年5月广西医科大学第一附属医院ATAAD术后低氧血症患者56例,将其随机分为肺复张组(n=36)及常规治疗组(n=20)。常规治疗组患者在肺保护性通气基础上行常规机械通气,肺复张组患者采用呼气末正压通气(positive end expiratory pressure,PEEP)递增法进行肺复张。比较两组患者治疗前后的动脉血气分析、呼吸力学指标、血流动力学指标和血清白细胞介素(interleukin,IL)-6及IL-10水平。结果 治疗后12h、24h,两组患者的动脉血氧分压(arterial partial pressure of oxygen,PaO_(2))、氧合指数(oxygenation index,OI)、肺静态顺应性(C_(stat))及肺动态顺应性(C_(dyn))均显著高于本组治疗前,肺泡动脉氧分压差[PO_(2)(A-a)]、呼吸指数(respiratory index,RI)、气道峰压(P_(peak))及气道平台压(P_(plat))均显著低于本组治疗前(P<0.05);肺复张组患者的PaO_(2)、OI、C_(stat)及C_(dyn)均显著高于常规治疗组,PO_(2)(A-a)、RI、P_(peak)及P_(plat)均显著低于常规治疗组(P<0.05)。肺复张组患者肺复张过程中收缩压及平均动脉压有所下降(P<0.05),中心静脉压有所升高(P<0.05),肺复张结束后均恢复至基线水平。治疗后12h,两组患者的血清IL-6和IL-10水平均显著低于本组治疗前(P<0.05)。结论 PEEP递增法肺复张可改善ATAAD术后低氧血症患者的氧合及肺顺应性,但对血流动力学存在一过性影响,治疗时应进行严密监测。
