Gomez-Morad Andrea D, Cravero Joseph P, Harvey Brian C, Bernier Rachel, Halpin Erin, Walsh Brian, Nasr Viviane G
From the Department of Anesthesiology Perioperative and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
Respiratory Motion, Inc, Waltham, Massachusetts.
Anesth Analg. 2017 Dec;125(6):1913-1919. doi: 10.1213/ANE.0000000000002029.
Pediatric patients following surgery are at risk for respiratory compromise such as hypoventilation and hypoxemia depending on their age, comorbidities, and type of surgery. Quantitative measurement of ventilation in nonintubated infants/children is a difficult and inexact undertaking. Current respiratory assessment in nonintubated patients relies on oximetry data, respiratory rate (RR) monitors, and subjective clinical assessment, but there is no objective measure of respiratory parameters that could be utilized to predict early respiratory compromise. New advances in technology and digital signal processing have led to the development of an impedance-based respiratory volume monitor (RVM, ExSpiron, Respiratory Motion, Inc, Waltham, MA). The RVM has been shown to provide accurate real-time, continuous, noninvasive measurements of tidal volume (TV), minute ventilation (MV), and RR in adult patients.In this prospective observational study, our primary aim was to determine whether the RVM accurately measures TV, RR, and MV in pediatric patients.
A total of 72 pediatric patients (27 females, 45 males), ASA I to III, undergoing general anesthesia with endotracheal intubation were enrolled. After endotracheal intubation, continuous data of MV, TV, and RR were recorded from the RVM and an in-line monitoring spirometer (NM3 monitor, Phillips Healthcare). RVM and NM3 measurements of MV, TV, and RR were compared during a 10-minute period prior to the incision ("Presurgery") and a 10-minute period after the end of surgery ("Postsurgery"). Relative errors were calculated over 1-minute segment within each 10-minute period. Bias, precision, and accuracy were calculated using Bland-Altman analyses and paired-difference equivalence tests were performed.
Combined across the Presurgery and Postsurgery periods, the RVM's mean measurement bias (RVM - NM3 measurement) for MV was -3.8% (95% limits of agreement) (±1.96 SD): (-19.9% to 12.2%), for TV it was -4.9 (-21.0% to 11.3%), and for RR it was 1.1% (-4.1% to 6.2%). The mean measurement accuracies for MV, TV, and RR were 11.9%, 12.0%, and 4.2% (0.6 breaths/min), respectively. Note that lower accuracy numbers correspond to more accurate RVM measurements. The equivalence tests rejected the null hypothesis that the RVM and NM3 have different mean values and conclude with 90% power that the measurements of MV, TV, and RR from the RVM and NM3 are equivalent within ±10%.
Our data indicate acceptable agreement between RVM and NM3 measurements in pediatric mechanically-ventilated patients. Future studies assessing the capability of the RVM to detect respiratory compromise in other clinical settings are needed.
接受手术的儿科患者存在呼吸功能受损的风险，如通气不足和低氧血症，这取决于他们的年龄、合并症和手术类型。对未插管婴儿/儿童的通气进行定量测量是一项困难且不准确的工作。目前对未插管患者的呼吸评估依赖于血氧饱和度数据、呼吸频率（RR）监测器和主观临床评估，但没有可用于预测早期呼吸功能受损的呼吸参数客观测量方法。技术和数字信号处理的新进展促使了基于阻抗的呼吸容积监测器（RVM，ExSpiron，Respiratory Motion公司，马萨诸塞州沃尔瑟姆）的开发。RVM已被证明能在成年患者中提供准确的实时、连续、无创的潮气量（TV）、分钟通气量（MV）和RR测量值。在这项前瞻性观察研究中，我们的主要目的是确定RVM是否能准确测量儿科患者的TV、RR和MV。
共纳入72例接受气管插管全身麻醉的儿科患者（27例女性，45例男性），ASA分级为I至III级。气管插管后，从RVM和在线监测肺活量计（NM3监测器，飞利浦医疗保健公司）记录MV、TV和RR的连续数据。在切口前10分钟（“术前”）和手术结束后10分钟（“术后”）期间比较RVM和NM3对MV、TV和RR的测量值。在每个10分钟时间段内的1分钟片段上计算相对误差。使用Bland-Altman分析计算偏差、精密度和准确性，并进行配对差异等效性检验。
在术前和术后期间综合来看，RVM对MV的平均测量偏差（RVM - NM3测量值）为-3.8%（95%一致性界限）（±1.96 SD）：（-19.9%至12.2%），对TV为-4.9（-21.0%至11.3%），对RR为1.1%（-4.1%至6.2%）。MV、TV和RR的平均测量准确性分别为11.9%、12.0%和4.2%（0.6次呼吸/分钟）。请注意，较低的准确性数值对应于RVM更准确的测量。等效性检验拒绝了RVM和NM3具有不同平均值的零假设，并以90%的把握得出结论，即RVM和NM3对MV、TV和RR的测量在±10%范围内是等效的。
我们的数据表明，在儿科机械通气患者中，RVM和NM3的测量值之间具有可接受的一致性。未来需要进行研究，评估RVM在其他临床环境中检测呼吸功能受损的能力。
