Riva T, Préel N, Theiler L, Greif R, Bütikofer L, Ulmer F, Seiler S, Nabecker S
Department of Anaesthesiology and Pain Medicine, Bern University Hospital, University of Bern, Bern, Switzerland.
Department of Anaesthesia, Kantonsspital Aarau, Aarau, Switzerland.
Anaesthesia. 2021 Jul;76(7):924-932. doi: 10.1111/anae.15335. Epub 2020 Dec 22.
Transnasal humidified rapid insufflation ventilatory exchange prolongs safe apnoeic oxygenation time in children. In adults, transnasal humidified rapid insufflation ventilatory exchange is reported to have a ventilatory effect with PaCO levels increasing less rapidly than without it. This ventilatory effect has yet to be reproduced in children. In this non-inferiority study, we tested the hypothesis that children weighing 10-15 kg exhibit no difference in carbon dioxide clearance when comparing two different high-flow nasal therapy flow rates during a 10-min apnoea period. Following standardised induction of anaesthesia including neuromuscular blockade, patients were randomly allocated to high-flow nasal therapy of 100% oxygen at 2 or 4 l.kg .min . Airway patency was ensured by continuous jaw thrust. The study intervention was terminated for safety reasons when SpO values dropped < 95%, or transcutaneous carbon dioxide levels rose > 9.3 kPa, or near-infrared spectroscopy values dropped > 20% from their baseline values, or after an apnoeic period of 10 min. Fifteen patients were included in each group. In the 2 l.kg .min group, mean (SD) transcutaneous carbon dioxide increase was 0.46 (0.11) kPa.min , while in the 4 l.kg .min group it was 0.46 (0.12) kPa.min . The upper limit of a one-sided 95%CI for the difference between groups was 0.07 kPa.min , lower than the predefined non-inferiority margin of 0.147 kPa.min (p = 0.001). The lower flow rate of 2 l.kg .min was non-inferior to 4 l.kg .min relative to the transcutaneous carbon dioxide increase. In conclusion, an additional ventilatory effect of either 2 or 4 l.kg .min high-flow nasal therapy in apnoeic children weighing 10-15 kg appears to be absent.
经鼻湿化快速吹气通气交换可延长儿童安全无呼吸氧合时间。在成人中，据报道经鼻湿化快速吹气通气交换具有通气作用，与未使用时相比，动脉血二氧化碳分压（PaCO）水平升高速度较慢。这种通气作用在儿童中尚未得到重现。在这项非劣效性研究中，我们检验了这样一个假设：在10分钟的无呼吸期内，比较两种不同的高流量鼻腔治疗流速时，体重10至15千克的儿童在二氧化碳清除方面没有差异。在包括神经肌肉阻滞的标准化麻醉诱导后，患者被随机分配接受2或4升·千克⁻¹·分钟⁻¹的100%氧气高流量鼻腔治疗。通过持续的下颌前推确保气道通畅。当血氧饱和度（SpO）值降至<95%，或经皮二氧化碳水平升至>9.3千帕，或近红外光谱值较基线值下降>20%，或在10分钟的无呼吸期后，出于安全原因终止研究干预。每组纳入15名患者。在2升·千克⁻¹·分钟⁻¹组中，经皮二氧化碳平均（标准差）增加为0.46（0.11）千帕·分钟⁻¹，而在4升·千克⁻¹·分钟⁻¹组中为0.46（0.12）千帕·分钟⁻¹。两组之间差异的单侧95%置信区间上限为0.07千帕·分钟⁻¹，低于预先定义的非劣效性界值0.147千帕·分钟⁻¹（p = 0.001）。相对于经皮二氧化碳增加，2升·千克⁻¹·分钟⁻¹的较低流速不劣于4升·千克⁻¹·分钟⁻¹。总之，对于体重10至15千克的无呼吸儿童，2或4升·千克⁻¹·分钟⁻¹的高流量鼻腔治疗似乎没有额外的通气作用。
