Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
Neonatology Division, University Children's Hospital, Uppsala, Sweden.
Paediatr Anaesth. 2022 Sep;32(9):1062-1069. doi: 10.1111/pan.14519. Epub 2022 Jul 13.
To reduce risk for intermittent hypoxia a high fraction of inspired oxygen is routinely used during anesthesia induction. This differs from the cautious dosing of oxygen during neonatal resuscitation and intensive care and may result in significant hyperoxia.
In a randomized controlled trial, we evaluated oxygenation during general anesthesia with a low (23%) vs a high (80% during induction and recovery, and 40% during maintenance) fraction of inspired oxygen, in newborn infants undergoing surgery.
Thirty-five newborn infants with postconceptional age of 35-44 weeks were included (17 infants in low and 18 in high oxygen group). Oxygenation was monitored by transcutaneous partial pressure of oxygen, pulse oximetry, and cerebral oxygenation. Predefined SpO2 safety targets dictated when to increase inspired oxygen.
At start of anesthesia, oxygenation was similar in both groups. Throughout anesthesia, the high oxygen group displayed significant hyperoxia with higher (difference-20.3 kPa, 95% confidence interval (CI)-28.4 to 12.2, p < .001) transcutaneous partial pressure of oxygen values than the low oxygen group. While SpO2 in the low oxygen group was lower (difference - 5.8%, 95% CI -9.3 to -2.4, p < .001) during anesthesia, none of the infants spent enough time below SpO safety targets to mandate supplemental oxygen, and cerebral oxygenation was within the normal range and not statistically different between the groups. Analysis of the oxidative stress biomarker urinary F -Isoprostane revealed no differences between the low and high oxygen group.
We conclude that in healthy newborn infants, use of low oxygen during general anesthesia was feasible, while the prevailing practice of using high levels of inspired oxygen resulted in significant hyperoxia. The trade-off between careful dosing of oxygen and risks of hypo- and hyperoxia in neonatal anesthesia should be further examined.
为了降低间歇性低氧的风险，在麻醉诱导期间通常会使用高浓度的吸入氧气。这与新生儿复苏和重症监护期间谨慎给氧不同，可能导致明显的高氧血症。
在一项随机对照试验中，我们评估了在接受手术的新生儿中，使用低（诱导和恢复期间为 23%，维持期间为 40%）和高（诱导期间为 80%，恢复期间为 40%）吸入氧分数的全身麻醉期间的氧合情况。
纳入了 35 名孕龄为 35-44 周的新生儿（低氧组 17 例，高氧组 18 例）。通过经皮氧分压、脉搏血氧饱和度和脑氧合监测氧合。预设的 SpO2 安全目标指导何时增加吸入氧。
麻醉开始时，两组的氧合情况相似。在整个麻醉过程中，高氧组显示出明显的高氧血症，经皮氧分压值明显高于低氧组（差值为 20.3 kPa，95%置信区间（CI）为 28.4 至 12.2，p < 0.001）。虽然低氧组的 SpO2 在麻醉期间较低（差值为 -5.8%，95% CI 为 -9.3 至 -2.4，p < 0.001），但没有一个婴儿在 SpO 安全目标以下的时间足够长，需要补充氧气，并且脑氧合处于正常范围内，两组之间无统计学差异。对氧化应激生物标志物尿 F-异前列烷的分析显示，低氧组和高氧组之间没有差异。
我们的结论是，在健康的新生儿中，全身麻醉时使用低氧是可行的，而目前使用高浓度吸入氧的做法导致了明显的高氧血症。在新生儿麻醉中，应进一步研究谨慎给氧与低氧和高氧风险之间的权衡。
