Balajthy Andras, Balazs Gergely, Kovacs Tamas, Belteki Gusztav
Department of Pediatrics, Division of Neonatology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Neonatal Intensive Care Unit, The Rosie Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
Pediatr Pulmonol. 2023 Jun;58(6):1703-1710. doi: 10.1002/ppul.26384. Epub 2023 Mar 17.
To analyse the relationship between peak inflating pressure, expired tidal volume, respiratory rate, and inspiratory time of volume-guaranteed ventilator inflations and pressure-supported spontaneous breaths during synchronized intermittent positive pressure mode with volume guarantee and pressure support (SIMV-VG-PS) in neonates.
Ventilator parameters were downloaded every second from 16 babies ventilated with SIMV-VG-PS mode using Dräger Babylog VN500 ventilators over 137 days. Transcutaneous carbon dioxide (tcCO ) data were also collected. Data were computationally analysed using Python. The average of each ventilator parameter was determined during each minute separately for ventilator inflations and for spontaneous breaths. These values were compared and their effect on tcCO levels was also analysed.
The relationship between the peak inflating pressure of the volume guaranteed inflations (PIP ) and pressure-supported spontaneous breaths (PIP ) was highly variable. The PIP /PIP ratio differed significantly from the value (0.66) targeted by clinicians (group median: 0.80, range: 0.50-1.00). PIP frequently exceeded PIP . When PIP /PIP was >0.66, the expired tidal volume and the rate of the pressure-supported spontaneous breaths were also significantly (p < 0.0001) higher, but there was no difference in tcCO levels. The flow-cycled spontaneous breaths had significantly shorter inspiratory times than ventilator inflations.
During SIMV-VG-PS it is difficult to ensure a pressure support level proportionate to the inflating pressure of ventilator inflations and to achieve the stability of tidal volumes.
分析在新生儿同步间歇正压通气模式下，容量保证通气时的峰值充气压力、呼出潮气量、呼吸频率和吸气时间，以及压力支持自主呼吸时这些参数之间的关系。
使用德尔格Babylog VN500呼吸机，在137天内对16例采用同步间歇正压通气模式-容量保证-压力支持（SIMV-VG-PS）通气的婴儿，每秒下载一次呼吸机参数。同时收集经皮二氧化碳（tcCO₂）数据。使用Python对数据进行计算分析。分别确定每分钟内呼吸机充气和自主呼吸时每个呼吸机参数的平均值。比较这些值，并分析它们对tcCO₂水平的影响。
容量保证通气的峰值充气压力（PIP₁）与压力支持自主呼吸的峰值充气压力（PIP₂）之间的关系高度可变。PIP₁/PIP₂比值与临床医生设定的值（0.66）有显著差异（组中位数：0.80，范围：0.50 - 1.00）。PIP₁经常超过PIP₂。当PIP₁/PIP₂>0.66时，呼出潮气量和压力支持自主呼吸的频率也显著更高（p < 0.0001），但tcCO₂水平无差异。流量切换的自主呼吸的吸气时间明显短于呼吸机充气时间。
在SIMV-VG-PS期间，难以确保与呼吸机充气压力成比例的压力支持水平并实现潮气量的稳定。
