Zanusso Francesca, Bellini Luca
Department of Animal Medicine, Production and Health, University of Padova, Legnaro, Italy.
PLoS One. 2025 Mar 31;20(3):e0319823. doi: 10.1371/journal.pone.0319823. eCollection 2025.
Multi-wave CO-oximetry, utilizing the oxygen reserve index (ORi), estimates arterial partial pressure of oxygen (PaO2) in mild hyperoxemia, between 100 and 200 mmHg, and concurrently quantifies local perfusion at the measurement site using the perfusion index (PI). This study explores how variations in PI influence the accuracy of ORi in estimating PaO2 in anesthetized dogs. Data from 37 mechanically ventilated dogs were retrospectively reanalyzed using a different approach. ORi and PI values were collected using a CO-oximeter. The data were categorized into four groups based on PI quartiles. In each group, the relationship between ORi and PaO2 was assessed using linear regression analysis, and the area under the receiver operating characteristic curve (AUROC) investigated the diagnostic performance of ORi in detecting PaO2 > 150 mmHg. Strong relationships between ORi and PaO2 were observed in groups with PI values < 2 (r2 ≥ 0.63). The AUROC of ORi for identifying PaO2 > 150 mmHg decreased with PI > 2 compared to lower values (0.76 vs > 0.88). In this study, PI values > 2 negatively impacted ORi's ability to estimate PaO2, likely due to fluctuations in blood flow perfusing the measurement site. The results of this study suggests that consideration of the PI value is essential when titrating oxygen therapy using ORi in anesthetized dogs.
多波长一氧化碳血氧测定法利用氧储备指数（ORi），可估算轻度高氧血症（动脉血氧分压[PaO2]在100至200 mmHg之间）时的动脉血氧分压，并同时使用灌注指数（PI）对测量部位的局部灌注进行量化。本研究探讨PI的变化如何影响ORi在麻醉犬中估算PaO2的准确性。采用不同方法对37只机械通气犬的数据进行回顾性重新分析。使用一氧化碳血氧仪收集ORi和PI值。根据PI四分位数将数据分为四组。在每组中，采用线性回归分析评估ORi与PaO2之间的关系，并通过受试者工作特征曲线下面积（AUROC）研究ORi检测PaO2>150 mmHg的诊断性能。在PI值<2的组中观察到ORi与PaO2之间存在强相关性（r2≥0.63）。与较低值相比，PI>2时，ORi识别PaO2>150 mmHg的AUROC降低（0.76对>0.88）。在本研究中，PI值>2对ORi估算PaO2的能力产生负面影响，这可能是由于测量部位血流波动所致。本研究结果表明，在麻醉犬中使用ORi滴定氧疗时，考虑PI值至关重要。
