Background

Significant challenges exist in measuring ventilation quality during out-of-hospital cardiopulmonary arrest (OHCA) outcomes. Since ventilation is associated with outcomes in cardiac arrest, tools that objectively describe ventilation dynamics are needed. We sought to characterize thoracic impedance (TI) oscillations associated with ventilation waveforms in the Pragmatic Airway Resuscitation Trial (PART).

Methods

We analyzed CPR process files collected from adult OHCA enrolled in PART. We limited the analysis to cases with simultaneous capnography ventilation recordings at the Dallas-Fort Worth site. We identified ventilation waveforms in the thoracic impedance signal by applying automated signal processing with adaptive filtering techniques to remove overlying artifacts from chest compressions. We correlated detected ventilations with the end-tidal capnography signals. We determined the amplitudes (Ai, Ae) and durations (Di, De) of both insufflation and exhalation phases. We compared differences between laryngeal tube (LT) and endotracheal intubation (ETI) airway management during mechanical or manual chest compressions using Mann-Whitney U-test.

Results

We included 303 CPR process cases in the analysis; 209 manual (77 ETI, 132 LT), 94 mechanical (41 ETI, 53 LT). Ventilation Ai and Ae were higher for ETI than LT in both manual (ETI: Ai 0.71 Ω, Ae 0.70 Ω vs LT: Ai 0.46 Ω, Ae 0.45 Ω; p < 0.01 respectively) and mechanical chest compressions (ETI: Ai 1.22 Ω, Ae 1.14 Ω VS LT: Ai 0.74 Ω, Ae 0.68 Ω; p < 0.01 respectively). Ventilations per minute, duration of TI amplitude insufflation and exhalation did not differ among groups.

Conclusion

Compared with LT, ETI thoracic impedance ventilation insufflation and exhalation amplitude were higher while duration did not differ. TI may provide a novel approach to characterizing ventilation during OHCA.

中文翻译：

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实用气道复苏试验中胸阻抗在心肺复苏期间通气特性中的新应用

背景

在院外心肺骤停 (OHCA) 结果期间测量通气质量存在重大挑战。由于通气与心脏骤停的结果相关，因此需要客观描述通气动态的工具。我们试图在实用气道复苏试验 (PART) 中描述与通气波形相关的胸阻抗 (TI) 振荡。

方法

我们分析了从参加 PART 的成人 OHCA 收集的 CPR 过程文件。我们将分析限制在达拉斯-沃思堡站点同时进行二氧化碳图通气记录的病例。我们通过应用自动信号处理和自适应滤波技术来识别胸部阻抗信号中的通气波形，以消除胸部按压中的叠加伪影。我们将检测到的通气与呼气末二氧化碳图信号相关联。我们确定了吸气和呼气阶段的振幅 (Ai, Ae) 和持续时间 (Di, De)。我们使用 Mann-Whitney U 检验比较了机械或手动胸外按压期间喉管 (LT) 和气管插管 (ETI) 气道管理的差异。

结果

我们在分析中纳入了 303 个 CPR 过程案例；209 手动（77 ETI，132 LT），94 机械（41 ETI，53 LT）。ETI 的通气 Ai 和 Ae 在手动（ETI：Ai 0.71 Ω，Ae 0.70 Ω 与 LT：Ai 0.46 Ω，Ae 0.45 Ω；分别为 p < 0.01）和机械胸外按压（ETI：Ai 1.22 Ω， Ae 1.14 Ω VS LT：Ai 0.74 Ω、Ae 0.68 Ω；分别为 p < 0.01）。每分钟通气量、TI 幅度吹气和呼气的持续时间在各组之间没有差异。

结论

与LT相比，ETI胸阻抗通气的吸气和呼气幅度更高，而持续时间没有差异。TI 可能提供一种新的方法来表征 OHCA 期间的通气。