全麻诱导期间空气面罩通气与纯氧面罩通气的无通气安全时限和气管插管时长的比较

摘要

目的 探索全麻诱导期间空气面罩通气与纯氧面罩通气的无通气安全时限和气管插管时长的比较.方法 选择80例ASA分级Ⅰ~Ⅱ级,预计无困难气道并拟在气管插管全麻下行择期手术的患者,通过随机数字法将患者随机分为2组:Ⅰ组患者全麻诱导前常规用纯氧行预给氧(n=40);Ⅱ组患者全麻诱导前空气面罩通气(n=40).两组患者均由两位有经验的麻醉医师在诱导期间进行面罩通气和气管插管,由助手进行气体的调整(给纯氧或给空气)和脉搏氧饱和度(SpO2)及相关指标的观察记录.在完成气管插管前SpO2低于90%则认定为失败病例,同时给予纯氧面罩通气.在气管插管完成后均不予通气,直至SpO2降至90%.记录失败病例数,无通气安全时限(即无通气状态下SpO2≥90%的持续时间)和气管插管时长.结果 两组均无失败病例.Ⅰ组和Ⅱ组的无通气安全时限分别为469.5±143.0 s和63.6±20.0 s,气管插管时长分别为34.4±12.6 s和32.8±9.6 s.两组的无通气安全时限均显著大于气管插管时长(P<0.01).两组的气管插管时长的差异以及气管插管完成时SpO2≥90%例数的差异均无统计学意义(P>0.05).Ⅱ组无通气安全时限显著小于Ⅰ组(P<0.01),且和体质量指数显著相关(P<0.05).结论 对于有经验的麻醉医师,空气面罩通气情况下的全麻诱导可提供较充足的无通气安全时限以完成气管插管.%Objective To compare the safe duration of apnea and intubation time between face mask ventilation with air and 100% oxygen during induction of general anesthesia.Methods Eighty adult patients with ASA class I or II without predicted difficult airways were scheduled for elective surgery under general anesthesia. The patients were randomized to receive anesthesia induction with preoxygenation [Group 1, n=40, fraction of inspired oxygen (FiO2)=1] or without preoxygenation (Group2,n=40,FiO2=0.21).Two experienced anesthesiologists performed the mask ventilation and tracheal intubation during induction, and the assistants adjusted the oxygen concentration and recorded the pulse oxygen saturation (SpO2) and other variables.The cases where SpO2decreased to below 90% before accomplishment of intubation were considered unsuccessful, and mask ventilation with 100% oxygen was given.After tracheal intubation,mechanical ventilation was not initiated until the SpO2decreased to 90%.The number of unsuccessful cases,the safe duration of apnea and intubation time were recorded in the two groups.Results There was no unsuccessful case in either groups.The safe duration of apnea was 469.5±143.0 s in Group 1 and 63.6±20.0 s in Group 2,and the intubation time was 34.4±12.6 s and 32.8±9.6 s,respectively.The safe duration of apnea was significantly longer than the intubation time in both groups(P<0.01).The intubation time and the number of cases with SpO2≥90% before completion of tracheal intubation were similar between the two groups. The safe duration of apnea was significantly shorter in Group 2 than in Group 1(P<0.01)and was correlated with the body mass index of the patients(P<0.05). Conclusion Anesthesia induction without preoxygenation can provide sufficient time for experienced anesthesiologists to complete tracheal intubation.