Background

This study aimed to evaluate the accuracy of expiratory time constant (RC_exp) to continuously calculate the airway resistance (R_aw).

Material and methods

A Respironics V60 ventilator was connected to a lung simulator for modeling different profiles of respiratory mechanics.

Results

During assisted ventilation, the respiratory system compliance (C_rs) calculation was always overestimated in most lung models. The R_aw estimation using the expiratory resistance (R_exp) method was close to the calculated value with the occlusion method during volume-controlled ventilation (VCV). In expiratory flow limitation (EFL) lung models, similar results were obtained in the estimation of inspiratory resistance (R_insp), but different variations were observed in the calculation of the R_exp. The results estimated with RC_exp and with dynamic signal analysis had significant variation and accuracy (p < 0.001).

Conclusion

The RC_exp method is a robust approach to provide real-time assessments of R_insp and R_exp in spontaneously breathing patients during noninvasive ventilation. An underestimation of R_exp was observed in EFL lung models.

中文翻译：

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无创通气中气道阻力的连续估计

背景

本研究旨在评估呼气时间常数 (RC _exp ) 以连续计算气道阻力 (R _aw ) 的准确性。

材料与方法

Respironics V60 呼吸机连接到肺模拟器，用于模拟不同的呼吸力学曲线。

结果

在辅助通气期间，呼吸系统顺应性 (C _rs ) 计算在大多数肺模型中总是被高估。在容量控制通气 (VCV) 期间，使用呼气阻力 (R _exp ) 方法的 R _aw估计值接近使用阻塞方法的计算值。_{在呼气流量限制 (EFL) 肺模型中，在吸气阻力 (R insp} )的估计中获得了类似的结果，但在 R _exp的计算中观察到了不同的变化。_{使用 RC exp}和动态信号分析估计的结果具有显着的变化和准确性 ( p < 0.001)。

结论

RC _exp方法是一种稳健的方法，可在无创通气期间对自主呼吸患者的 R _insp和 R _exp进行实时评估。在 EFL 肺模型中观察到了对 R _exp的低估。