Objective

To measure changes in end-expiratory lung impedance (EELI) as a marker of functional residual capacity (FRC) during the entire extubation procedure of very preterm infants.

Methods

Prospective observational study in preterm infants born at 26–32 weeks gestation being extubated to non-invasive respiratory support. Changes in EELI and cardiorespiratory parameters (heart rate, oxygen saturation) were recorded at pre-specified events during the extubation procedure compared to baseline (before first handling of the infant).

Results

Overall, 2912 breaths were analysed in 12 infants. There was a global change in EELI during the extubation procedure (p = 0.029). EELI was lowest at the time of extubation [median (IQR) difference to baseline: −0.30 AU/kg (−0.46; −0.14), corresponding to an FRC loss of 10.2 ml/kg (4.8; 15.9), p_adj = 0.004]. The biggest EELI loss occurred during adhesive tape removal [median change (IQR): −0.18 AU/kg (−0.22; −0.07), p_adj = 0.004]. EELI changes were highly correlated with changes in the SpO₂/FiO₂ ratio (r = 0.48, p < 0.001). Forty per cent of FRC was re-recruited at the tenth breath after the initiation of non-invasive ventilation (p < 0.001).

Conclusions

The extubation procedure is associated with significant changes in FRC. This study provides novel information for determining the optimal way of extubating a preterm infant.

Impact

• This study is the first to examine the development of lung volumes during the entire extubation procedure including the impact of associated events.

• The extubation procedure significantly affects functional residual capacity with a loss of approximately 10 ml/kg at the time of extubation.

• Removal of adhesive tape is the major contributing factor to FRC loss during the extubation procedure.

• Functional residual capacity is regained within the first breaths after initiation of non-invasive ventilation and is further increased after turning the infant into the prone position.

中文翻译：

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DELUX 研究：早产儿拔管过程中肺容量的发展

客观的

测量极早产儿整个拔管过程中呼气末肺阻抗 (EELI) 的变化，作为功能残气量 (FRC) 的标志物。

方法

对妊娠 26-32 周出生的早产儿进行前瞻性观察研究，以进行无创呼吸支持。与基线（第一次处理婴儿之前）相比，在拔管过程中预先指定的事件中记录了 EELI 和心肺参数（心率、氧饱和度）的变化。

结果

总体而言，对 12 名婴儿的 2912 次呼吸进行了分析。在拔管过程中，EELI 发生了整体变化（p  = 0.029）。拔管时 EELI 最低 [中位数 (IQR) 与基线的差异：-0.30 AU/kg (-0.46; -0.14)，对应于 FRC 损失 10.2 ml/kg (4.8; 15.9)，p _adj  = 0.004 ]。最大的 EELI 损失发生在胶带去除期间 [中位变化 (IQR)：-0.18 AU/kg (-0.22; -0.07)，p _adj  = 0.004]。EELI 变化与 SpO ₂ /FiO ₂比率的变化高度相关（r  = 0.48，p  < 0.001）。在开始无创通气后的第十次呼吸时，40% 的 FRC 被重新招募（p  < 0.001)。

结论

拔管过程与 FRC 的显着变化有关。这项研究为确定早产儿拔管的最佳方式提供了新的信息。

影响

• 这项研究首次检查了整个拔管过程中肺容量的发展，包括相关事件的影响。

• 拔管过程显着影响功能残余容量，拔管时损失约 10 ml/kg。

• 在拔管过程中，去除胶带是导致 FRC 损失的主要因素。

• 功能性残余容量在开始无创通气后的第一次呼吸内恢复，并在婴儿转入俯卧位后进一步增加。