Evaluation of lung recruitment maneuvers in acute respiratory distress syndrome using computer simulation.
Evaluation of lung recruitment maneuvers in acute respiratory distress syndrome using computer simulation.
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DOI：
10.1186/s13054-014-0723-6
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发表时间：
2015-01-12
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影响因子：
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通讯作者：
Hardman JG
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文献类型：
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作者：
Das A;Cole O;Chikhani M;Wang W;Ali T;Haque M;Bates DG;Hardman JG
由于患者群体和疾病状态的异质性以及各种实际问题，通过临床试验直接比较不同招募策略（RMs）对急性呼吸窘迫综合征（ARDS）患者的相对疗效是困难的。对于使用RMs确保维持有效肺复吸所需的呼气末正压（PEEP）的最小值，也存在很大的不确定性。我们使用患者特异性计算模拟来分析三种不同的RMs如何改善生理反应，并研究不同水平的PEEP如何有助于维持有效的肺补充。我们使用计算模拟器对5名“虚拟”ARDS患者进行了实验，该模拟器再现了单个ARDS患者对一系列呼吸机输入的反应的多变量临床数据集的静态和动态特征。在一系列不同的压力设置下，实施并评估了三种招募策略（持续膨胀（SI）、最大招募策略（MRS）和延长招募策略（PRM））。所有的操作都显示了气体交换的改善，但改善的程度和持续时间差异很大，正如观察到的操作机制一样。在所有的动作中，维持足够的术后PEEP水平对于避免肺泡单位的悬崖边缘型再塌陷至关重要。对于所有5例患者，MRS表现出最持久的氧合改善，我们发现35 cm H2O的PEEP设置和固定的驱动压力为15 cm H2O（高于PEEP）足以达到95%的恢复。随后，我们发现滴定到16 cm H2O的PEEP能够在所有5例患者中保持95%的招募。降低最初在MRS中规定的PEEP峰值水平似乎有很大的余地，从而避免将肺部暴露在不必要的高压下。更广泛地说，我们的研究强调了计算机模拟的巨大潜力，可以帮助评估不同招募策略的有效性，了解其操作模式，优化个体患者的rm，并支持临床医生合理设计改进的治疗策略。本文的在线版本（doi:10.1186/s13054-014-0723-6）包含补充资料，仅供授权用户使用。
Direct comparison of the relative efficacy of different recruitment maneuvers (RMs) for patients with acute respiratory distress syndrome (ARDS) via clinical trials is difficult, due to the heterogeneity of patient populations and disease states, as well as a variety of practical issues. There is also significant uncertainty regarding the minimum values of positive end-expiratory pressure (PEEP) required to ensure maintenance of effective lung recruitment using RMs. We used patient-specific computational simulation to analyze how three different RMs act to improve physiological responses, and investigate how different levels of PEEP contribute to maintaining effective lung recruitment. We conducted experiments on five ‘virtual’ ARDS patients using a computational simulator that reproduces static and dynamic features of a multivariable clinical dataset on the responses of individual ARDS patients to a range of ventilator inputs. Three recruitment maneuvers (sustained inflation (SI), maximal recruitment strategy (MRS) followed by a titrated PEEP, and prolonged recruitment maneuver (PRM)) were implemented and evaluated for a range of different pressure settings. All maneuvers demonstrated improvements in gas exchange, but the extent and duration of improvement varied significantly, as did the observed mechanism of operation. Maintaining adequate post-RM levels of PEEP was seen to be crucial in avoiding cliff-edge type re-collapse of alveolar units for all maneuvers. For all five patients, the MRS exhibited the most prolonged improvement in oxygenation, and we found that a PEEP setting of 35 cm H2O with a fixed driving pressure of 15 cm H2O (above PEEP) was sufficient to achieve 95% recruitment. Subsequently, we found that PEEP titrated to a value of 16 cm H2O was able to maintain 95% recruitment in all five patients. There appears to be significant scope for reducing the peak levels of PEEP originally specified in the MRS and hence to avoid exposing the lung to unnecessarily high pressures. More generally, our study highlights the huge potential of computer simulation to assist in evaluating the efficacy of different recruitment maneuvers, in understanding their modes of operation, in optimizing RMs for individual patients, and in supporting clinicians in the rational design of improved treatment strategies. The online version of this article (doi:10.1186/s13054-014-0723-6) contains supplementary material, which is available to authorized users.