From the Department of Physiology and Pharmacology (FYFA), C3, Eriksson I Lars, PA Lönnqvist Group, Section of Anesthesiology and Intensive Care, Karolinska Institute, Stockholm, Sweden.
Department of Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden.
Anesth Analg. 2024 Oct 1;139(4):781-788. doi: 10.1213/ANE.0000000000007083. Epub 2024 Aug 2.
Mixed venous oxygen saturation (SvO 2 ) is a critical variable in the assessment of oxygen supply and demand but is rarely used in children due to the invasive nature of pulmonary artery catheters. The aim of this prospective, observational study was to investigate the accuracy of noninvasively measured SvO 2 acquired by the novel capnodynamic method, based on differential Fick equation (Capno-SvO 2 ), against gold standard CO-oximetry.
Capno-SvO 2 was compared to SvO 2 measured by pulmonary artery blood gas CO-oximetry in children undergoing cardiac catheter interventions and subjected to moderate hemodynamic challenges. Bland-Altman analysis was used to describe the agreement of absolute values between CO-oximetry and Capno-SvO 2 , and a concordance rate was calculated to evaluate the ability of Capno-SvO 2 to track change.
Twenty-five procedures were included in the study. Capno-SvO 2 showed a bias toward CO-oximetry of +3 percentage points; upper and lower limits of agreement were +11 percentage points (95% confidence interval [CI], 9-14) and -5 percentage points (95% CI, -8 to -3), respectively. The concordance rate was 92% (95% CI, 89-96).
In conclusion, this first clinical application of a novel concept for noninvasive SvO 2 monitoring without the need for a pulmonary artery catheter indicates that Capno-SvO 2 generates absolute values and trending capacity in close agreement with the gold standard reference method.
混合静脉血氧饱和度（SvO 2 ）是评估氧供和氧需的关键变量，但由于肺动脉导管的侵袭性，在儿童中很少使用。本前瞻性观察研究的目的是评估基于差分式 Fick 方程（Capno-SvO 2 ）的新型无创性 SvO 2 测量方法的准确性，该方法基于二氧化碳动态测量法，与金标准 CO-血氧仪进行比较。
在接受心脏导管介入治疗并接受中度血流动力学挑战的儿童中，将基于二氧化碳动态测量法的 Capno-SvO 2 与肺动脉血气 CO-血氧仪测量的 SvO 2 进行比较。Bland-Altman 分析用于描述 CO-血氧仪和 Capno-SvO 2 之间绝对值的一致性，并计算符合率以评估 Capno-SvO 2 跟踪变化的能力。
本研究共纳入 25 例操作。Capno-SvO 2 与 CO-血氧仪相比存在 3 个百分点的偏倚；一致性界限为上、下限分别为+11 个百分点（95%置信区间，9-14）和-5 个百分点（95%置信区间，-8 至-3）。符合率为 92%（95%置信区间，89-96）。
总之，这项新型非侵入性 SvO 2 监测技术的首次临床应用，无需肺动脉导管，表明 Capno-SvO 2 可生成与金标准参考方法高度一致的绝对值和趋势能力。
