Karlsson Victoria, Sporre Bengt, Hellström-Westas Lena, Ågren Johan
Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
Unit for Pediatric Anesthesia, University Hospital, Uppsala, Sweden.
Paediatr Anaesth. 2017 Dec;27(12):1235-1240. doi: 10.1111/pan.13266. Epub 2017 Oct 26.
Endtidal (ET) measurement of carbon dioxide is well established for intraoperative respiratory monitoring of adults and children, but the method's accuracy for intraoperative use in small newborn infants has been less extensively investigated.
The aim of this study was to compare carbon dioxide from ET measurements with arterialized capillary blood samples in newborn infants during general anesthesia and surgery.
Endtidal carbon dioxide was continuously measured during anesthesia and surgery and compared with simultaneous blood gas analyses obtained from capillary blood samples. Fifty-nine sample sets of ET to blood gas carbon dioxide were obtained from 23 prospectively enrolled infants with a gestational age of 23-41 weeks and a birth weight of 670-4110 g.
Endtidal levels of carbon dioxide were considerably lower in all sample sets and only 4/23 individual ET-blood gas sample pairs differed <7.5 mm Hg (1 kPa). Bland-Altman analysis indicated a poor agreement with a bias of -13 ± 7 mm Hg and a precision of ±14 mm Hg. The performance of ET measurements was particularly poor in infants weighing below 2.5 kg, in infants in need of respiratory support prior to anesthesia, and when the true (blood gas) carbon dioxide level was high, above 45 mm Hg.
Main-stream capnography during anesthesia and surgery correlated poorly to blood gas values in small and/or respiratory compromised infants. We conclude that caution should be exercised when relying solely on ET measurements to guide mechanical ventilation in the OR.
呼气末二氧化碳（ET）测量在成人和儿童术中呼吸监测中已得到广泛应用，但该方法在小新生儿术中使用的准确性研究较少。
本研究旨在比较全身麻醉和手术期间新生儿呼气末二氧化碳测量值与动脉化毛细血管血样中的二氧化碳值。
在麻醉和手术期间持续测量呼气末二氧化碳，并与同时从毛细血管血样中获得的血气分析结果进行比较。从23例孕周为23 - 41周、出生体重为670 - 4110 g的前瞻性纳入婴儿中获取了59组呼气末二氧化碳与血气二氧化碳样本。
所有样本组中呼气末二氧化碳水平均显著较低，仅4/23个个体呼气末二氧化碳 - 血气样本对的差异<7.5 mmHg（1 kPa）。Bland - Altman分析表明一致性较差，偏差为 - 13 ± 7 mmHg，精密度为±14 mmHg。在体重低于2.5 kg的婴儿、麻醉前需要呼吸支持的婴儿以及真实（血气）二氧化碳水平高于45 mmHg时，呼气末二氧化碳测量的表现尤其差。
麻醉和手术期间的主流二氧化碳监测图与小婴儿和/或呼吸功能受损婴儿的血气值相关性较差。我们得出结论，在手术室仅依靠呼气末二氧化碳测量来指导机械通气时应谨慎。
