Neonatal Intensive Care Unit, The Rosie Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
St. Edmund's College, University of Cambridge, Cambridge, UK.
Pediatr Pulmonol. 2020 May;55(5):1131-1138. doi: 10.1002/ppul.24724. Epub 2020 Mar 9.
Pressure rise time (PRT), also known as slope time to the peak inflating pressure can be set on some modern neonatal ventilators. On other ventilators, PRT is determined by the set circuit flow. Changing slope time can affect mean airway pressure (MAP), oxygenation, and carbon dioxide elimination. Our aim was to investigate the effect of PRT on ventilator parameters and gas exchange during volume-guaranteed ventilation.
In a crossover study, 12 infants weighing greater than 2 kg were ventilated using a Dräger Babylog VN500 ventilator with synchronized intermittent positive pressure ventilation with volume guarantee (SIPPV-VG) and pressure support ventilation with volume guarantee (PSV-VG). During both modes PRTs between 0.08 and 0.40 seconds were used in 15-minute epochs. Data from the ventilator and patient monitors were downloaded with 1- and 100-Hz sampling rate and analyzed using the Python computer language.
During PSV-VG, longer PRTs were associated with longer inspiratory time (P < .0001) and with lower peak inflating pressure (PIP; P = .003), but the MAP was similar. During SIPPV-VG the PIP was not significantly different; however, MAP was lower with longer PRT (P = .001). With a short PRT (0.08 seconds), the PIP was higher during PSV-VG than during SIPPV-VG (19.8 vs 16.5 mbar; P = .042). There were no significant differences in tidal volume delivery, respiratory rate, minute volume, oxygen saturations, or end-tidal CO with different PRTs in either mode.
During SIPPV-VG or PSV-VG, using short or long PRTs affects some ventilation parameters but does not significantly change oxygenation or carbon dioxide elimination.
压力上升时间（PRT），也称为到达峰压的斜率时间，可在一些现代新生儿呼吸机上设置。在其他呼吸机上，PRT 由设定的回路流量决定。改变斜率时间会影响平均气道压（MAP）、氧合和二氧化碳清除。我们的目的是研究 PRT 在容量保证通气期间对呼吸机参数和气体交换的影响。
在一项交叉研究中，12 名体重超过 2kg 的婴儿使用 Dräger Babylog VN500 呼吸机进行通气，采用同步间歇正压通气（SIPPV-VG）和压力支持通气（PSV-VG）与容量保证。在这两种模式下，使用 0.08 至 0.40 秒的 PRT 进行 15 分钟的时间段。使用 1Hz 和 100Hz 的采样率从呼吸机和患者监护仪下载数据，并使用 Python 计算机语言进行分析。
在 PSV-VG 期间，较长的 PRT 与较长的吸气时间相关（P<.0001），与较低的峰压（PIP；P=.003）相关，但 MAP 相似。在 SIPPV-VG 期间，PIP 没有显着差异；然而，较长的 PRT 会导致 MAP 降低（P=.001）。在 PRT 较短（0.08 秒）时，PSV-VG 期间的 PIP 高于 SIPPV-VG（19.8 与 16.5mbar；P=.042）。在两种模式下，使用不同的 PRT 时，潮气量输送、呼吸频率、分钟通气量、氧饱和度或呼气末二氧化碳均无显着差异。
在 SIPPV-VG 或 PSV-VG 期间，使用短或长 PRT 会影响一些通气参数，但不会显着改变氧合或二氧化碳清除。
