重度窒息新生儿早期通气治疗失败与循环系统损害的关系

Relationship between poor response to early mechanical ventilation and circulatory involvement in neonates with severe asphyxia

目的探讨循环系统损害对重度窒息所致的呼吸衰竭新生儿早期机械通气疗效的影响。方法产时重度窒息导致呼吸衰竭的143例足月儿和105例早产儿各自分为有循环系统损害的观察组(足月儿组n=61,早产儿组n=49)和无循环系统损害的对照组(足月儿组n=82,早产儿组n=56),回顾性分析观察组与同胎龄对照组的Apgar评分差异和观察组的持续肺动脉高压、休克、心力衰竭、严重心律失常的发生情况,并对观察组最初机械通气1 h的疗效、呼吸机参数、血气分析指标与同胎龄对照组进行比较。结果足月儿观察组5 min和10 min Apgar评分≤7分的病例为46例(75.4%)和20例(32.8%),早产儿观察组为43例(87.8%)和17例(34.7%),都高于各自的对照组(P<0.05或P<0.01);足月儿观察组的持续肺动脉高压、心源性休克、失血性休克、心力衰竭和严重心律失常的发生率为52.5%、57.4%、21.3%、54.1%和11.5%;早产儿观察组的发生率为30.6%、71.4%、28.6%、59.2%和12.2%。上机通气1 h,足月儿观察组通气治疗有效者为28例(44.3%),对照组为76例(92.7%)(P<0.01);早产儿观察组通气治疗有效者为15例(30.6%),对照组为49例(87.5%)(P<0.01)。观察组的呼吸机通气参数明显高于同胎龄对照组,而且达到新生儿机械通气常规标准的较高水平,潮气量接近15 ml/kg,但pH值、PaO2均明显低于各自的对照组(P<0.01),PaCO2则高于各自的对照组(P<0.01)。对循环系统损害进行干预后,足月儿观察组93.4%、早产儿观察组91.8%的血气值达到理想水平,最终治愈率观察组与同胎龄对照组无显著差异(P>0.05)。结论循环系统损害是重度窒息新生儿呼吸衰竭早期机械通气治疗无效的重要原因,及时纠正可改善通气效果和预后。

Objective To investigate the effects of circulatory involvement on early ventilation in neonates with respiratory failure due to severe asphyxia. Methods One hundred and forty-three term neonates and one hundred and five preterm neonates with respiratory failure due to severe asphyxia at birth were divided into two observation groups with circulatory involvement （term group n = 61, preterm group n = 49） and two control groups without circulatory involvement （term group n = 82, preterm group n = 56）. The differences of Apgar scores between observation groups and control groups of the same gestational age, and the incidences of persistent pulmonary hypertension of the newborn （PPHN）, cardiogenic shock, exsanguine shock, cardiac failure and severe cardiac arrhythmia in each observation group were retrospectively studied. The effects of mechanical ventilation, mechanical ventilative parameters and results of blood gas analysis in observation groups at 1 hour post mechanical ventilation were compared with those in control groups of the same gestational age. Results The cases of Apgar scores ≤7 at 5min and 10min were 46 （75.4%） and 20 （32.8%） in term observation group and 43 （87.8%） and 17 （34.7%） in preterm observation group, which were significantly higher than those in respective control group （P 〈 0.05 or P 〈 0.01 ）. The proportion of persistent pulmonary hypertension of the newborn （PPHN）, cardiogenic shock, exsanguine shock, cardiac failure and severe cardiac arrhythrnia was 52.5%,57.4%,21.3%,54.1% and 11.5% in term observation group, and 30.6%, 71.4 % ,28.6 % ,59.2 % and 12.2 % in preterm observation group. At 1 hour post mechanical ventilation, the effective cases of mechanical ventilation were 28 （44.3 % ） in term observation group and 76 （92.7 % ） in term control group （P 〈 0.01） ; 15 （30.6%） in preterm observation group and 49 （87.5%） in preterm control group （P 〈 0.01 ）. The mechanical ventilative parameters in observation groups were higher than those in control groups of the same gestational age（P 〈 0.01 ）, and the higher levels of mechanical ventilative norm in the neonate were reached in observation groups, where the tidal volumes approached 15 ml/kg, however pH and PaO2 were lower and PaCO2 was higher in term observation group and in preterm observation group, compared with those in respective control group（ P 〈 0.01 ）. After the intervention was made for the circulatory involvement, the blood gas parameters of observation groups turned to the ideal levels in 93.4 % term neonates and in 91.8 % preterm neonates. No difference was found in recovery rate between observation groups and control groups of the same gestational age （P 〉 0.05 ）. Conclusion The circulatory involvement can lead to poor response to early mechanical ventilation of respiratory failure in the neonates with severe asphyxia, the intervention for it was shown to be beneficial to the outcome of the neonates with severe asphyxia.