Neonatal Research, Murdoch Childrens Research Institute, Parkville, Vic, Australia. nicholas.kiraly @ mcri.edu.au
Neonatology. 2011;99(1):78-82. doi: 10.1159/000316854. Epub 2010 Aug 24.
Closed endotracheal suction interferes with mechanical ventilation received by infants, but the change to ventilation may be different when ventilator modes that target expired tidal volume (VT(e)) are used.
To measure airway pressure and tidal volume distal to the endotracheal tube (ETT) during and after closed suction in a volume-targeted ventilation mode with the Dräger Babylog 8000+, and to determine the time until VT(e) returns to the baseline level.
In this benchtop study, closed suction was performed on 2.5- to 4.0-mm ETTs connected to a test lung. 5-8 French suction catheters were used at suction pressures of 80-200 mm Hg during tidal-volume-targeted ventilation.
During catheter insertion and suction, circuit inflating pressure increased and tidal volume was maintained, except when a large catheter relative to the ETT was used, in which case tidal volume decreased. End-expiratory pressure distal to the ETT was reduced during suction by up to 75 cm H(2)O while circuit end-expiratory pressure was unchanged. Reduction in end-expiratory pressure distal to the ETT was greatest with large catheters and high suction pressures. Following suction, circuit and tracheal inflating pressures increased and tidal volume increased before returning to baseline in 8-12 s.
Closed endotracheal suction interferes with ventilator function in volume-targeted mode, with substantially negative intratracheal pressure during suction, and the potential for high airway pressures and tidal volumes following the procedure. These effects should be considered and pressure limits set appropriately whenever using volume-targeted ventilation.
密闭式吸痰会干扰婴儿接受的机械通气，但当使用以潮气末容积（VT(e)）为目标的通气模式时，通气的变化可能会有所不同。
在容积目标通气模式下，使用 Dräger Babylog 8000+ 测量气管内导管（ETT）远端在密闭式吸痰期间和之后的气道压力和潮气量，并确定 VT(e) 恢复到基线水平所需的时间。
在这项台式研究中，将密闭式吸痰应用于连接到测试肺的 2.5-4.0 毫米 ETT。在潮气量目标通气时，使用 5-8 法国吸引导管，吸引压力为 80-200 毫米汞柱。
在导管插入和吸引过程中，回路充气压力增加，潮气量得到维持，但当导管相对于 ETT 较大时，潮气量会减少。在吸痰过程中，ETT 远端的呼气末压力降低最多可达 75 厘米水柱，而回路呼气末压力保持不变。在吸引过程中，ETT 远端的呼气末压力降低最大，与大口径导管和高吸引压力有关。在吸痰后，回路和气管充气压力增加，潮气量增加，然后在 8-12 秒内恢复到基线。
密闭式吸痰会干扰容积目标通气模式下的呼吸机功能，在吸痰过程中会产生明显的负性气道压力，且在操作后存在高气道压力和潮气量的潜在风险。在使用容积目标通气时，应考虑这些影响并适当设置压力限制。
