From the Department of Anesthesiology (M.D.C.), Sanatorio Finochietto, Buenos Aires, Argentina; Simulation Center of Buenos Aires Association of Anesthesia (A.B.), Analgesia y Reanimation, Buenos Aires, Argentina; Department of Anesthesiology (L.H.P.), Children Hospital Dr. Orlando Alassia, Santa Fe, Argentina; Instituto Tecnológico Buenos Aires (ITBA) (M.M.), Buenos Aires, Argentina; Department of Anesthesiology and Intensive Care Medicine (S.H.B.), Rostock University Medical Center, Rostock, Germany; and Department of Anesthesia (G.T.), Hospital Privado de Comunidad, Mar del Plata, Argentina.
Simul Healthc. 2024 Aug 1;19(4):254-262. doi: 10.1097/SIH.0000000000000717.
Volumetric capnography depicts volumetric capnograms [ie, the plot of expired carbon dioxide (CO 2 ) over the tidal volume]. This bench study aimed to determine the reliability, accuracy, and precision of a novel infant simulator for volumetric capnography. This simulator would be clinically valuable for teaching purposes because it reflects the entire cardiopulmonary physiology within 1 breath.
An infant lung simulator was fed with CO 2 supplied by a mass flow controller (VCO 2-IN ) and ventilated using standard settings. A volumetric capnograph was placed between the endotracheal tube and the ventilatory circuit. We simulated ventilated babies of different body weights (2, 2.5, 3, and 5 kg) with a VCO 2 ranging from 12 to 30 mL/min. The correlation coefficient ( r2 ), bias, coefficient of variation (CV = SD/ x × 100), and precision (2 × CV) between the VCO 2-IN and the elimination of CO 2 recorded by the capnograph (VCO 2-OUT ) were calculated. The quality of the capnogram's waveforms was compared with real ones belonging to anesthetized infants using an 8-point scoring system, where 6 points or greater meant that the simulated capnogram showed good, 5 to 3 points acceptable, and less than 3 points an unacceptable shape.
The correlation between VCO 2-IN and VCO 2-OUT was r2 = 0.9953 ( P < 0.001), with a bias of 0.16 (95% confidence intervals from 0.12 to 0.20) mL/min. The CV was 5% or less and the precision was 10% or less. All simulated capnograms showed similar shapes compared with real babies, scoring 6 points for 3 kg and 6.5 points for 2-, 2.5-, and 5-kg babies.
The simulator of volumetric capnograms was reliable, accurate, and precise for simulating the CO 2 kinetics of ventilated infants.
容积描记法描绘容积二氧化碳描记图（即呼出二氧化碳（CO2）随潮气量的变化图）。本基础研究旨在确定一种新型婴儿容积描记法模拟器的可靠性、准确性和精密度。该模拟器对于教学目的具有重要的临床价值，因为它在 1 次呼吸内反映了整个心肺生理学。
婴儿肺模拟器通过质量流量控制器（VCO2-IN）提供 CO2，并采用标准设置进行通气。将容积描记器放置在气管内导管和通气回路之间。我们模拟了不同体重（2、2.5、3 和 5 公斤）的通气婴儿，VCO2 范围为 12 至 30 毫升/分钟。计算 VCO2-IN 与容积描记器记录的 CO2 消除量（VCO2-OUT）之间的相关系数（r2）、偏差、变异系数（CV=SD/x×100）和精密度（2×CV）。使用 8 分制评分系统将波形的质量与麻醉婴儿的实际波形进行比较，其中 6 分或更高表示模拟的二氧化碳描记图显示良好，5 至 3 分表示可接受，小于 3 分表示形状不可接受。
VCO2-IN 与 VCO2-OUT 之间的相关性为 r2=0.9953（P<0.001），偏差为 0.16（95%置信区间为 0.12 至 0.20）毫升/分钟。变异系数为 5%或更低，精密度为 10%或更低。与真实婴儿相比，所有模拟的二氧化碳描记图显示出相似的形状，体重为 3 公斤的模拟图得 6 分，体重为 2、2.5 和 5 公斤的模拟图得 6.5 分。
容积二氧化碳描记法模拟器在模拟通气婴儿 CO2 动力学方面具有可靠性、准确性和精密度。
