不同的吸入氧浓度对小儿先天性心脏病围术期气体交换的影响

Influence of different types of ventilation on gas exchange in children wih congenital heart disease children during general anesthesia and postoperation

目的:纯氧常规用于麻醉前预先吸氧和麻醉诱导,但吸高浓度氧会发生肺不张,可在全麻期间损害肺气体交换,本研究以吸入氧浓度(fraction of inspiration oxygen,FiO2)为纯氧(1 L/L)通气为对照,观察气管插管后FiO2为0.5 L/L混合空气通气对气体交换的影响。方法:先天性心脏病(非紫绀型)手术患者102名,年龄1月～13岁,均以1 L/L O2在麻醉前预先吸氧3 min和(麻醉诱导时)面罩通气2 min,接下来气管插管。这些患者随机分为2组:混合通气组(51例,行FiO2为0.5 L/L O2通气),纯氧通气组(51例,行1 L/L O2通气)。分别于预先吸氧前和气管插管后30 min、入ICU、拔管后30 min以及术后前3 d做动脉血气分析,并计算动脉血氧分压(PaO2)/FiO2比值。结果:PaO2术后在入ICU(0.6 L/L FiO2)、拔管后30 min(1.5 L/min)面罩吸氧两个时间点,动脉血氧PaO2在混合通气组明显高于纯氧通气组,PaO2/FiO2值在插管后30 min、入ICU(0.6 L/L FiO2)、拔管后30 min(1.5 L/min)面罩吸氧等时间点混合通气组明显高于纯氧通气组(P<0.05),且混合通气组的ICU机械通气时间、住留时间及住院时间均明显缩短。结论:先天性心脏病(非紫绀型)手术患儿全麻时,混合通气较纯氧通气能够显著的改善肺的气体交换功能和预后。

To evaluate the effect of ventilation with 0.5 L/L FiO2 in air or 1 L/L 02 following intubation on gas exchange. METHODS： One hundred and two patients （aged 1 month to 13 years） undergoing surgical cardiac intervention with congenital heart disease （CHD） （non-cyanosis） were given 1 L/L 02 for preoxygenation （3 min） and ventilation by mask （ 2 min）. Following intubation, patients were randomly divided into two groups （51 patients in each group） and ventilated with either 0. 5 L/L FiO2 in air or 1 L/L O2. Arterial blood gases were obtained for analysis before preoxygenation, 30 min following intubation, on entering the ICU, 30 min after extubation and 3 days postoperation. Subsequently, PaO2/FiO2 ratios were calculated. RESULTS： PaO2 values on entering ICU and 30 min after extubation were significantly improved in the group receiving 0. 5 L/L FiO2 group than those in the group receiving 1 L/L 02. PaOE/FiO2 ratio in the 0. 5 L/L FiO2 group was significantly improved at the following time points： 30 min after intubation, upon entering the ICU and 30 min after extubation. Mechanical ventilation