为了预氧合和呼吸暂停氧合的目的,可以在麻醉诱导时给予高流量鼻氧。据称这种干预措施可以在呼吸暂停期间增强二氧化碳的消除,但是这种情况发生的程度仍然难以量化。气体交换的最佳鼻氧流速也是未知的。在这项研究中,114例患者在50升接受了高流量鼻氧的预氧合。min-1.在呼吸暂停发作时,患者被随机分配接受三种鼻氧气流量中的一种:0l。分钟-1;70升。min-1;或120升。min-1.呼吸暂停4分钟后,所有氧气输送都停止了,进行了气管插管,当SpO2为92%时,氧气输送重新开始。呼吸暂停第一分钟的平均(SD)PaCO2升高为1.39(0.39)kPa,1.41(0.29)kPa,和1.26(0.38)kPa在0升。min-1,70升min-1和120l.min-1组,分别为p=0.16。在第二次期间,第三和第四分钟的呼吸暂停,PaCO2的平均上升率(SD)为0.34(0.08)kPa。min-1,0.36(0.06)kPa。min-1和0.37(0.07)kPa。min-1在0l中。min-1,70升min-1和120l.min-1组,分别为p=0.17。呼吸暂停4分钟后,中值(IQR[范围])动脉氧分压在0升。min-1,70升min-1和120l.min-1组为24.5(18.6-31.4[12.3-48.3])kPa;36.6(28.1-43.8[9.8-56.9])kPa;和37.6(26.5-45.4[11.0-56.6])kPa,分别为;p<0.001。在0升呼吸暂停发作后去饱和至92%的中位数(IQR[范围])时间。min-1,70升min-1和120l.min-1组,分别为412(347-509[190-796])s;533(467-641[192-958])s;和531(462-681[326-1007])s,分别为;p<0.001。总之,在接受高流量鼻氧治疗的呼吸暂停患者和未接受高流量鼻氧治疗的患者之间,动脉血中的二氧化碳蓄积率没有显著差异.
High-flow nasal oxygen can be administered at induction of anaesthesia for the purposes of pre-oxygenation and apnoeic oxygenation. This intervention is claimed to enhance carbon dioxide elimination during
apnoea, but the extent to which this occurs remains poorly quantified. The optimal nasal oxygen flow rate for gas exchange is also unknown. In this
study, 114 patients received pre-oxygenation with high-flow nasal oxygen at 50 l.min-1. At the onset of
apnoea, patients were allocated randomly to receive one of three nasal oxygen flow rates: 0 l.min-1; 70 l.min-1; or 120 l.min-1. After 4 minutes of
apnoea, all oxygen delivery was ceased, tracheal intubation was performed, and oxygen delivery was recommenced when SpO2 was 92%. Mean (SD) PaCO2 rise during the first minute of
apnoea was 1.39 (0.39) kPa, 1.41 (0.29) kPa, and 1.26 (0.38) kPa in the 0 l.min-1, 70 l.min-1 and 120 l.min-1 groups, respectively; p = 0.16. During the second, third and fourth minutes of apnoea, mean (SD) rates of rise in PaCO2 were 0.34 (0.08) kPa.min-1, 0.36 (0.06) kPa.min-1 and 0.37 (0.07) kPa.min-1 in the 0 l.min-1, 70 l.min-1 and 120 l.min-1 groups, respectively; p = 0.17. After 4 minutes of apnoea, median (IQR [range]) arterial oxygen partial pressures in the 0 l.min-1, 70 l.min-1 and 120 l.min-1 groups were 24.5 (18.6-31.4 [12.3-48.3]) kPa; 36.6 (28.1-43.8 [9.8-56.9]) kPa; and 37.6 (26.5-45.4 [11.0-56.6]) kPa, respectively; p < 0.001. Median (IQR [range]) times to desaturate to 92% after the onset of apnoea in the 0 l.min-1, 70 l.min-1 and 120 l.min-1 groups, were 412 (347-509 [190-796]) s; 533 (467-641 [192-958]) s; and 531 (462-681 [326-1007]) s, respectively; p < 0.001. In conclusion, the rate of carbon dioxide accumulation in arterial blood did not differ significantly between apnoeic patients who received high-flow nasal oxygen and those who did not.