Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy.
Division of Pediatrics and Neonatal Critical Care and Transportation, Medical Center "A. Béclère", Paris Saclay University Hospitals, Assistance Publique-Hôpitaux de Paris, Paris, France.
Pediatr Pulmonol. 2020 Aug;55(8):1955-1962. doi: 10.1002/ppul.24852. Epub 2020 May 27.
Despite technical specifications of neonatal mechanical ventilators (MVs) guarantee clinically irrelevant discrepancies between the set and the delivered values of ventilation parameters, previous studies reported large deviations. Most studies characterized performances of a given model/brand by studying a single device, disregarding possible intramodel differences, and leaving the accuracy of the ventilation parameters effectively delivered in clinical settings unknown. The aim of this study was to evaluate the real-life accuracy of pressure and volume parameters delivered by neonatal ventilators ready to be used on patients in neonatal intensive care units (NICUs).
In vitro study.
Neonatal ventilators (n = 33 of 8 different models) available in four European NICUs.
The MVs were connected to a test lung (resistance = 50 cmH O*s/L, compliance = 0.35 mL/cmH O) provided with pressure and flow sensors. MVs were tested over two different ventilation modes randomly: (a) pressure controlled (PC) with a peak inspiratory pressure (PIP) of 22 cmH O, and (b) PC with volume targeted ventilation (VTV) with a tidal volume (V ) of 6 mL. In all tests, positive end-expiratory pressure (PEEP) was set to 6 cmH O, respiratory rate to 45 breaths/min, inspiratory time to 0.33 seconds, and oxygen fraction to 0.3.
During PC the median (min-max) values delivered were: PEEP = 5.84(4.95-6.48) cmH O, PIP = 21.63(20.04-22.62) cmH O. During VTV, V was 5.94(4.63-8.01) mL. V was considerably variable, ranging from -22% to +33% of the set and displayed values. Differences in accuracy among devices of the same model were comparable to those found among different models.
Our findings suggest that loss of accuracy in ventilation variables is likely related to daily use of the devices rather than weakness in the design or manufacturing process, urging the improvement of maintenance and quality control procedures to preserve the performances of neonatal MVs during their entire lifespan.
尽管新生儿机械呼吸机（MV）的技术规格保证了通气参数的设定值与实际输送值之间存在临床无相关性的差异，但先前的研究报告显示存在较大偏差。大多数研究通过研究单一设备来描述特定型号/品牌的性能，而忽略了可能存在的模型内差异，从而使临床实际输送的通气参数的准确性仍未可知。本研究旨在评估准备在新生儿重症监护病房（NICU）使用的新生儿呼吸机输送压力和容量参数的实际准确性。
体外研究。
来自欧洲 4 家 NICU 的 8 种不同型号的 33 台新生儿呼吸机。
将 MV 连接到一个带有压力和流量传感器的测试肺（阻力=50cmH2O*s/L，顺应性=0.35mL/cmH2O）。MV 以两种不同的通气模式随机进行测试：（a）以 22cmH2O 的峰值吸气压力（PIP）进行压力控制（PC）；（b）以 6mL 的目标容量通气（VTV）进行 PC。在所有测试中，均将呼气末正压（PEEP）设置为 6cmH2O，呼吸频率为 45 次/分，吸气时间为 0.33 秒，氧分数为 0.3。
在 PC 期间，输送的中位数（最小值-最大值）值为：PEEP=5.84（4.95-6.48）cmH2O，PIP=21.63（20.04-22.62）cmH2O。在 VTV 期间，V 为 5.94（4.63-8.01）mL。V 变化较大，范围在设定值的-22%到+33%之间。同一型号设备之间的准确性差异与不同型号设备之间的差异相当。
我们的研究结果表明，通气变量的准确性损失可能与设备的日常使用有关，而不是与设计或制造过程的缺陷有关，这促使我们改进维护和质量控制程序，以在新生儿 MV 的整个使用寿命内保持其性能。
