经喉罩气道行呼吸力学强迫振荡评估在兔中的可行性。

Feasibility of forced oscillatory assessment of respiratory mechanics across a laryngeal mask airway in rabbits.

机构信息

Unit for Anaesthesiological Investigations, Department of Acute Medicine, University of Geneva, Geneva,Switzerland.

出版信息

Physiol Meas. 2019 Jul 1;40(6):065001. doi: 10.1088/1361-6579/ab1f13.

DOI:10.1088/1361-6579/ab1f13

PMID:31051489

Abstract

OBJECTIVES

The forced oscillation technique (FOT) is the method of choice for assessment of respiratory tissue mechanics. A laryngeal mask airway (LMA) is increasingly used to secure the airways in subjects under sedation or general anesthesia. While FOT is routinely performed using an endotracheal tube (ETT), the accuracy of information about airway and tissue mechanics obtained with FOT using a LMA has not been characterized. Therefore, we compared the mechanical parameters obtained with FOT using LMA and ETT in rabbits.

APPROACH

FOT was performed through a LMA at normal and reduced oscillatory amplitudes in anesthetized and mechanically ventilated rabbits (n = 9) at positive end-expiratory pressures (PEEP) of 3 and 6 cmHO. These measurements were repeated at normal amplitude for the same animal using an ETT. Airway resistance, inertance, respiratory tissue damping (G) and elastance (H) were measured under each condition by FOT. The potential bias of the distensible upper airways when FOT was applied using LMA was assessed with a simulation study.

MAIN RESULTS

Values of parameters reflecting airway mechanics were significantly higher when measured using LMA at both PEEPs and oscillatory amplitudes than with ETT. Conversely, regardless of the condition, there was a correlation (r = 0.89 both at normal and reduced amplitudes; p < 0.0001) with good agreement (mean bias of 8.8 cmHO/l and 11.3 cmHO/l) in H, whereas G was systematically lower when obtained with LMA than with ETT at PEEP 3 (21.1% ± 7.2% and 9.6% ± 6.9% at normal and reduced oscillatory amplitudes, respectively) and 6 cmHO (15.1% ± 8.2%, 1.6% ± 9.4%, p < 0.05 for all).

SIGNIFICANCE

Mechanical properties of the airways and the respiratory tissues, particularly for respiratory tissue stiffness, can be reliably assessed using LMA. However, the involvement of a longer laryngo-tracheo-bronchial pathway when using LMA should be considered for airway resistance and inertance, whereas upper airway shunting may affect the assessment of respiratory tissue damping.

摘要

目的

呼吸组织力学的首选评估方法是强迫振荡技术（FOT）。喉罩气道（LMA）越来越多地用于在镇静或全身麻醉下的受试者中保持气道通畅。虽然 FOT 通常使用气管内导管（ETT）进行，但使用 LMA 进行 FOT 获得的气道和组织力学信息的准确性尚未得到描述。因此，我们比较了在兔体内使用 LMA 和 ETT 进行 FOT 时获得的机械参数。

方法

在正压通气并处于麻醉状态的兔中，在呼气末正压（PEEP）为 3 和 6 cmH2O 时，通过 LMA 在正常和降低的振荡幅度下进行 FOT（n=9）。对于同一动物，在相同条件下使用 ETT 重复进行正常幅度的 FOT。通过 FOT 在每种条件下测量气道阻力、惯性、呼吸组织阻尼（G）和弹性（H）。使用模拟研究评估当使用 LMA 进行 FOT 时可扩张上气道的潜在偏差。

主要结果

在两种 PEEP 和两种振荡幅度下，使用 LMA 测量的反映气道力学的参数值均显著高于使用 ETT 时的参数值。相反，无论条件如何，H 值都存在相关性（正常和降低幅度的 r 值分别为 0.89；p<0.0001），且一致性良好（均值偏差分别为 8.8 cmH2O/l 和 11.3 cmH2O/l），而在 PEEP 为 3 和 6 cmH2O 时，与 ETT 相比，LMA 获得的 G 值始终较低（正常和降低幅度的分别为 21.1%±7.2%和 9.6%±6.9%；分别为 15.1%±8.2%、1.6%±9.4%，p<0.05）。