Stratton Michael, Overmann Kevin, Zhang Yin, Ruddy Richard
Division of Emergency Medicine Cincinnati Children's Hospital Medical Center Cincinnati Ohio USA.
Department of Pediatrics University of Cincinnati College of Medicine Cincinnati Ohio USA.
J Am Coll Emerg Physicians Open. 2024 Apr 25;5(3):e13170. doi: 10.1002/emp2.13170. eCollection 2024 Jun.
The bias of capnometry (ETCO) and venous carbon dioxide (vpCO) among pediatric emergency department (PED) patients triaged to critical care areas is unknown. We aimed to explore correlations and bias between ETCO and vpCO¸and identify predictors of bias.
This was an observational, video-based, retrospective study comparing ETCO and vpCO. Pediatric patients with simultaneous ETCO and vpCO data were included. Our primary aim utilized linear regressions to determine correlations and Bland-Altman analysis to assess bias. Our secondary aim utilized multiple regression to identify clinical covariates contributing to bias. Covariates included age, respiratory rate, heart rate, mean arterial blood pressure, capnometry interface, PED diagnosis, and PED disposition.
A total of 200 PED patients with ETCO and vpCO data were included. The median (interquartile range [IQR]) ETCO, vpCO, and ΔCO in mmHg were 38 (32, 46), 49 (41, 61), and 11 (4, 20), respectively. ETCO ( = 0.76) and ΔCO ( = 0.71) were highly correlated with vpCO. The mean bias between ETCO and vpCO was -14.1 mmHg (95% confidence interval [CI], -41.9 -13.7). The bias between ETCO and vpCO increased at higher values of each measure. ETCO sampling interface was the only independent predictor of vpCO in our multivariate analysis. Patients requiring bag-valve mask (BVM) ventilation had the highest median bias between ETCO and vpCO (29 mmHg, IQR 15, 37).
ETCO and vpCO were highly correlated. However, bias increased at higher levels of both ETCO and vpCO. Among PED patients, ETCO's ability to approximate vpCO diminishes with worsening hypercarbic respiratory failure.
在分诊至重症监护区域的儿科急诊科（PED）患者中，呼气末二氧化碳监测（ETCO）和静脉血二氧化碳（vpCO）之间的偏差尚不清楚。我们旨在探讨ETCO和vpCO之间的相关性及偏差，并确定偏差的预测因素。
这是一项基于视频的观察性回顾性研究，比较ETCO和vpCO。纳入同时有ETCO和vpCO数据的儿科患者。我们的主要目的是利用线性回归确定相关性，并采用Bland-Altman分析评估偏差。次要目的是利用多元回归确定导致偏差的临床协变量。协变量包括年龄、呼吸频率、心率、平均动脉血压、呼气末二氧化碳监测接口、PED诊断和PED处置情况。
共纳入200例有ETCO和vpCO数据的PED患者。ETCO、vpCO和ΔCO（以mmHg为单位）的中位数（四分位间距[IQR]）分别为38（32，46）、49（41，61）和11（4，20）。ETCO（r = 0.76）和ΔCO（r = 0.71）与vpCO高度相关。ETCO和vpCO之间的平均偏差为-14.1 mmHg（95%置信区间[CI]，-41.9 -13.7）。在各测量值较高时，ETCO和vpCO之间的偏差增加。在我们的多变量分析中，ETCO采样接口是vpCO的唯一独立预测因素。需要球囊面罩（BVM）通气的患者，ETCO和vpCO之间的中位数偏差最高（29 mmHg，IQR 15，37）。
ETCO和vpCO高度相关。然而，在ETCO和vpCO水平较高时，偏差增加。在PED患者中，随着高碳酸血症性呼吸衰竭的加重，ETCO接近vpCO的能力下降。
