更高水平的自主呼吸可诱导肺复张，并减少实验性肺损伤中的整体压力/应变。

Higher levels of spontaneous breathing induce lung recruitment and reduce global stress/strain in experimental lung injury.

机构信息

From the Pulmonary Engineering Group, Department of Anesthesiology and Intensive Care Medicine, University Hospital Dresden, Technische Universität Dresden, Dresden, Germany (A.G., A.B., N.C., A.B., S.Z., C.U., P.M.S., T.K., and M.G.d.A.); Department of Electric Engineering, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil (A.B.); Institute of Informatics and Biometry, Dresden, Germany (B.W.); Institute of Nuclear Medicine, University Hospital Dresden, Dresden, Germany (G.W., M.A., and J.K.); and IRCCS San Martino Hospital, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy (P.P.).

出版信息

Anesthesiology. 2014 Mar;120(3):673-82. doi: 10.1097/ALN.0000000000000124.

DOI:10.1097/ALN.0000000000000124

PMID:24406799

Abstract

BACKGROUND

Spontaneous breathing (SB) in the early phase of the acute respiratory distress syndrome is controversial. Biphasic positive airway pressure/airway pressure release ventilation (BIPAP/APRV) is commonly used, but the level of SB necessary to maximize potential beneficial effects is unknown.

METHODS

Experimental acute respiratory distress syndrome was induced by saline lung lavage in anesthetized and mechanically ventilated pigs (n = 12). By using a Latin square and crossover design, animals were ventilated with BIPAP/APRV at four different levels of SB in total minute ventilation (60 min each): (1) 0% (BIPAP/APRV0%); (2) greater than 0 to 30% (BIPAP/APRV>0-30%); (3) greater than 30 to 60% (BIPAP/APRV>30-60%); and (4) greater than 60% (BIPAP/APRV>60%). Gas exchange, hemodynamics, and respiratory variables were measured. Lung aeration was assessed by high-resolution computed tomography. The distribution of perfusion was marked with Ga-labeled microspheres and evaluated by positron emission tomography.

RESULTS

The authors found that higher levels of SB during BIPAP/APRV (1) improved oxygenation; (2) decreased mean transpulmonary pressure (stress) despite increased inspiratory effort; (3) reduced nonaerated lung tissue, with minimal changes in the distribution of perfusion, resulting in decreased low aeration/perfusion zones; and (4) decreased global strain (mean ± SD) (BIPAP/APRV0%: 1.39 ± 0.08; BIPAP/APRV0-30%: 1.33 ± 0.03; BIPAP/APRV30-60%: 1.27 ± 0.06; BIPAP/APRV>60%: 1.25 ± 0.04, P < 0.05 all vs. BIPAP/APRV0%, and BIPAP/APRV>60% vs. BIPAP/APRV0-30%).

CONCLUSIONS

In a saline lung lavage model of experimental acute respiratory distress syndrome in pigs, levels of SB during BIPAP/APRV higher than currently recommended for clinical practice, that is, 10 to 30%, improve oxygenation by increasing aeration in dependent lung zones without relevant redistribution of perfusion. In presence of lung recruitment, higher levels of SB reduce global stress and strain despite an increase in inspiratory effort.

摘要

背景

急性呼吸窘迫综合征早期自主呼吸存在争议。双相气道正压通气/气道压力释放通气（BIPAP/APRV）被广泛应用，但最大化潜在有益效果所需的自主呼吸水平尚不清楚。

方法

在麻醉和机械通气的猪中通过生理盐水肺灌洗诱导实验性急性呼吸窘迫综合征（n=12）。采用拉丁方和交叉设计，动物在总分钟通气量的 4 种不同自主呼吸水平下接受 BIPAP/APRV 通气（各 60 分钟）：（1）0%（BIPAP/APRV0%）；（2）0%至 30%（BIPAP/APRV>0-30%）；（3）30%至 60%（BIPAP/APRV>30-60%）；（4）大于 60%（BIPAP/APRV>60%）。测量气体交换、血流动力学和呼吸变量。通过高分辨率计算机断层扫描评估肺充气情况。用 Ga 标记的微球标记灌注分布，并用正电子发射断层扫描进行评估。

结果

作者发现，BIPAP/APRV 期间更高水平的自主呼吸（1）改善了氧合；（2）尽管吸气努力增加，但降低了平均跨肺压（压力）；（3）减少了非充气肺组织，灌注分布变化最小，导致低充气/灌注区减少；（4）降低了整体应变（平均值±标准差）（BIPAP/APRV0%：1.39±0.08；BIPAP/APRV0-30%：1.33±0.03；BIPAP/APRV30-60%：1.27±0.06；BIPAP/APRV>60%：1.25±0.04，均 P<0.05 与 BIPAP/APRV0%相比，BIPAP/APRV>60%与 BIPAP/APRV0-30%相比）。