Neonatology Association Limited, Obstetrix Medical Group of Phoenix, Mednax, Phoenix, Arizona.
Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Los Angeles County+USC Medical Center, Keck School of Medicine, University of Southern California, Los Angeles.
JAMA Netw Open. 2019 Mar 1;2(3):e191179. doi: 10.1001/jamanetworkopen.2019.1179.
Oxygenation index (OI), an invasive measurement, is routinely used as a marker of severity of hypoxemic respiratory failure in neonates. Oxygen saturation index (OSI) is a noninvasive measurement and has been shown to be a reliable surrogate marker of OI in children and adults with respiratory failure.
To evaluate the correlation of OI with OSI and to derive and validate predictive OI from noninvasive OSI measurements for clinically relevant OI values.
DESIGN, SETTING, AND PARTICIPANTS: For this retrospective cohort study, 220 neonates requiring invasive mechanical ventilation for hypoxic respiratory failure during the first 3 days of admission were recruited from a level III neonatal intensive care unit during a 6-year period, from January 1, 2012, to December 31, 2017. Data were analyzed from January 2017 to December 2017.
The primary outcome was correlation of OI with OSI, analyzed using Pearson correlation coefficient. The secondary outcome was derivation and validation of OI from OSI. The data were split into derivative samples, from which a predictive equation for OI was derived using generalized linear model, and a validation sample was used to assess the predictive ability of the derived OI. Bland-Altman plot was used to assess agreement between derived OI and measured OI.
A total of 1442 paired OI and OSI measurements from 220 infants (190 preterm and 30 term; median [interquartile range] gestational age, 29 [26-33] weeks; mean [SD] birth weight, 1602 [1092] g) were recorded during the study. The median (interquartile range) number of samples was 5 (3-9) per patient. Overall, OI and OSI showed strong correlation (r = 0.89). The correlation was stronger in preterm infants (<28 weeks, r = 0.93; 28-33 weeks, r = 0.93) and within an oxygen saturation range of 85% to 95% (r = 0.94). The predictive derivative equation showed a strong linear association and good agreement in both derivation and validation data sets, with strong accuracy measures of derived OI for OI cutoffs of 5, 10, 15, 20, and 25.
A strong correlation of OI with OSI was found. Derived OI from OSI was in good agreement and strongly predictive of clinically relevant OI cutoffs from 5 to 25. Oxygenation index derived from noninvasive sources may be useful to reliably assess severity of respiratory failure and response to therapy on a continuous basis.
氧合指数（OI）是一种有创测量指标，常用于评估新生儿低氧性呼吸衰竭的严重程度。氧饱和度指数（OSI）是非侵入性测量指标，已被证明是儿童和成人呼吸衰竭时 OI 的可靠替代标志物。
评估 OI 与 OSI 的相关性，并从非侵入性 OSI 测量值中推导出和验证用于临床相关 OI 值的预测 OI。
设计、设置和参与者：这是一项回顾性队列研究，在 6 年期间（2012 年 1 月 1 日至 2017 年 12 月 31 日），从一个三级新生儿重症监护病房招募了 220 名因缺氧性呼吸衰竭而在入院后前 3 天需要进行有创机械通气的新生儿。数据分析于 2017 年 1 月至 2017 年 12 月进行。
主要结局是使用 Pearson 相关系数分析 OI 与 OSI 的相关性。次要结局是从 OSI 中推导出 OI。数据被分为衍生样本，使用广义线性模型从衍生样本中推导出预测 OI 的方程，并使用验证样本评估推导出的 OI 的预测能力。Bland-Altman 图用于评估推导出的 OI 与测量的 OI 之间的一致性。
在研究期间共记录了来自 220 名婴儿（190 名早产儿和 30 名足月儿；中位[四分位数范围]胎龄，29[26-33]周；平均[标准差]出生体重，1602[1092]g）的 1442 对 OI 和 OSI 测量值。每名患者的中位数（四分位数范围）样本数为 5（3-9）。总体而言，OI 和 OSI 显示出很强的相关性（r=0.89）。在早产儿（<28 周，r=0.93；28-33 周，r=0.93）和氧饱和度范围为 85%至 95%（r=0.94）时，相关性更强。预测衍生方程在推导和验证数据集均显示出很强的线性关联和良好的一致性，对于 OI 截断值为 5、10、15、20 和 25 的衍生 OI 具有很强的准确性测量。
发现 OI 与 OSI 之间存在很强的相关性。从 OSI 中推导的 OI 与临床相关 OI 截断值具有良好的一致性，且具有很强的预测性，范围从 5 到 25。非侵入性来源的氧合指数衍生值可能有助于可靠地连续评估呼吸衰竭的严重程度和对治疗的反应。
