Pathophysiologic basis of acute respiratory distress in patients who fail a trial of weaning from mechanical ventilation
Pathophysiologic basis of acute respiratory distress in patients who fail a trial of weaning from mechanical ventilation
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DOI：
10.1164/ajrccm.155.3.9117025
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发表时间：
1997-03-01
影响因子：
24.7
通讯作者：
Tobin, MJ
中科院分区：
文献类型：
--
作者：
Jubran, A;Tobin, MJ
为了确定慢性阻塞性肺疾病（COPD）患者急性呼吸窘迫和呼吸衰竭的机制，我们研究了17例呼吸机支持的自主呼吸试验失败的患者和14例耐受该试验并成功拔管的患者。在脱机试验前，两组之间的最大吸气压无统计学差异（p = 0.48）。在停止呼吸机时，失败组立即出现浅快呼吸，动态肺弹性（Edyn（L））（p < 0.01）和内源性呼气末正压（PEEP（i），p < 0.03）值高于成功组。在试验开始和结束之间，失败组Edyn（L）（p < 0.0001）和PEEP（i）（p < 0.0001）进一步增加，吸气阻力（p < 0.009）和吸气压力-时间乘积（PTP）（p < 0.0001）增加。试验结束时PTP的划分显示PEEP（i）组分增加了111%，非PEEP（i）弹性组分增加了33%，阻力组分增加了42%（所有p < 0.0001）。尽管PTP增加，但13例失败患者的Pa-CO2增加。在试验结束时，失败组的PTP和Pa-CO2的乘积（一种二氧化碳清除效率低下的指标）是成功组的两倍多（p < 0.0005）。因此，在脱机尝试失败期间发生急性呼吸窘迫是由于肺力学恶化，与快速浅呼吸一起导致CO2清除效率低下。
To determine the mechanisms of acute respiratory distress and failure in patients with chronic obstructive pulmonary disease (COPD), we studied 17 ventilator-supported patients who failed a trial of spontaneous breathing and 14 patients who tolerated such a trial and were successfully extubated. Immediately before the weaning trials, maximal inspiratory pressure was not statistically different between the two groups (p = 0.48). On discontinuation of the ventilator, the failure group immediately developed rapid shallow breathing, and higher values of dynamic lung elastance (Edyn(L)) (p < 0.01) and intrinsic positive end-expiratory pressure (PEEP(i), p < 0.03) than did the success group. Between the onset and end of the trial, the failure group developed further increases in Edyn(L) (p < 0.0001) and PEEP(i) (p < 0.0001), and increases in inspiratory resistance (p < 0.009) and inspiratory pressure-time product (PTP) (p < 0.0001). Partitioning of PTP at the end of the trial revealed a 111% increase in the PEEP(i) component, a 33% increase in the non-PEEP(i) elastic component, and a 42% increase in the resistive component (all p < 0.0001). Despite the increase in PTP, 13 of the failure patients developed an increase in Pa-CO2. The product of PTP and Pa-CO2, an index of inefficient CO2 clearance, was more than twice as high in the failure group than in the success group at the end of the trial (p < 0.0005). Thus, development of acute respiratory distress during a failed weaning attempt was due to worsening of pulmonary mechanics, which in conjunction with rapid shallow breathing led to inefficient clearance of CO2.