Smallwood Craig D, Kheir John N, Walsh Brian K, Mehta Nilesh M
Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine
Harvard Medical School, Boston, Massachusetts.
Respir Care. 2017 Apr;62(4):475-480. doi: 10.4187/respcare.05115. Epub 2017 Jan 17.
Although accurate quantification of oxygen consumption (V̇ ) and carbon dioxide elimination (V̇ ) provides important insights into a patient's nutritional and hemodynamic status, few devices exist to accurately measure these parameters in children. Therefore, we assessed the accuracy and agreement of 2 devices currently on the market using a pediatric in vitro model of gas exchange.
We utilized a Huszczuk simulation model, which simulates oxygen consumption and carbon dioxide production using gas dilution, to examine the accuracy of two FDA-cleared respiratory modules (E-COVX and E-sCAiOVX-00). V̇ and V̇ were set at 20, 40, 60, and 100 mL/min, ranges typical for infant and pediatric patients. Bland-Altman analysis was used to calculate the bias and limits of agreement of each device relative to simulated values for V̇ and V̇ .
The E-COVX mean percentage bias (limits of agreement) was -26.3% (-36.1 to -16.6%) and -39.3% (-47.5 to -31.1%) for V̇ and V̇ , respectively. The mean bias (limits of agreement) for the E-aCAiOVX-00 was -0.5% (-13.3 to 12.3%) and -6.0% (-13.8 to 1.7%) for V̇ and V̇ , respectively.
The E-COVX demonstrated bias and limits of agreement that were not clinically acceptable; therefore, application of this module to pediatric patients would not be recommended. The new module, E-sCAiOVX, demonstrated acceptable bias and limits of agreement for the V̇ and V̇ in the range 40-100 mL/min (which corresponds to patients in the range of ∼5-16 kg).
尽管准确量化耗氧量（V̇ ）和二氧化碳排出量（V̇ ）能为了解患者的营养和血流动力学状态提供重要信息，但目前几乎没有设备能够准确测量儿童的这些参数。因此，我们使用气体交换的儿科体外模型评估了市场上现有的两种设备的准确性和一致性。
我们利用Huszczuk模拟模型，该模型通过气体稀释模拟耗氧量和二氧化碳产生量，以检验两个获得美国食品药品监督管理局（FDA）批准的呼吸模块（E-COVX和E-sCAiOVX-00）的准确性。V̇ 和V̇ 设定为20、40、60和100 mL/分钟，这是婴儿和儿科患者的典型范围。采用Bland-Altman分析来计算每个设备相对于V̇ 和V̇ 模拟值的偏差和一致性界限。
E-COVX的平均百分比偏差（一致性界限）对于V̇ 和V̇ 分别为-26.3%（-36.1至-16.6%）和-39.3%（-47.5至-31.1%）。E-sCAiOVX-00的平均偏差（一致性界限）对于V̇ 和V̇ 分别为-0.5%（-13.3至12.3%）和-6.0%（-13.8至1.7%）。
E-COVX表现出的偏差和一致性界限在临床上不可接受；因此，不建议将该模块应用于儿科患者。新模块E-sCAiOVX在40 - 100 mL/分钟范围内（对应于约5 - 16 kg的患者）对于V̇ 和V̇ 表现出可接受的偏差和一致性界限。
