Clinical Reasearch Of Heliox Combined Synchronized Intermittent Mandatory Ventilation In Treating Meconium Aspiration Syndrom

Background and objectiveMeconium aspiration syndrome(MAS)is a common respiratory disease in neonates,which is caused by chemical inflammation and alveolar mechanical obstruction resulting from inhalation of meconium stained amniotic fluid,has clinical manifestations such as respiratory distress,lung injury and persistent pulmonary hypertension(PPHN),and can lead to various organs,systems damage syndrome,and high mortality.Severe MAS infant often need mechanical ventilation and other combination therapies(including extracorporeal membrane lung,no inhalation and pulmonary surfactant and high oscillatory ventilation,etc.),But the clinical treatment of children with severe MAS is still difficult,and the mortality rate is high.The helium oxygen mixture(helium,oxygen mixture,heliox)may provide a new approach for the treatment of infant with severe MAS,and this study also explores the potential value of its application in clinical treatment.Tracheal intubation and mechanical ventilation can rapidly improve oxygenation status,and is one of the common NICU rescue measures.However,due to small bronchial cartilage and the poor foreign body removal ability of the respiratory tract,invasive ventilation for valuable treatment time for children will also cause complications such as pneumothorax,pulmonary hemorrhage,and respiratory tract infection etc.Synchronized intermittent mandatory ventilation(SIMV)is a kind of intermittent positive pressure ventilation(IPPV)in children with spontaneous breathing combined with intermittent demand ventilation mode,provides preset ventilation according to the patients' respiratory requirements,has advantages of less man-machine confrontation production,effective reduction of airway pressure,reduced weaning difficulties and preventing respiratory muscle atrophy.And it has been an important means for treating MAS.In recent years,it has been found that helium oxygen mixture(Heliox)has a unique advantage in children with respiratory diseases.The newborn immature lungs and respiratory tract stenosis,the low density of the physical characteristics of Heliox make the oxygen more easily pass through the narrowed airway lumen due to inflammation,which can effectively reduce airway resistance,increase the oxygen content,and improve the symptoms of respiratory system.This study uses synchronized intermittent mandatory ventilation support combined with inhalation of mixture of helium and oxygen for treating meconium aspiration syndrome,observes the effects of heliox on neonatal myocardial enzymes and blood inflammatory factors,and explores its clinical mechanism..MethodsNewborns with MAS were selected from NICU ward of Daping Hospital from March 1,2014 to May 30,2015,and were randomly divided into Heliox group and control group.All cases were treated with SIMV as respiratory support mode;Heliox group inhaled Heliox70(He70%,O230%)for 6h and then changed to inhale oxygen and air mixed gas(O230%);the control group inhaled air oxygen mixture.Main outcome measures included oxygenation index(OI)and extubation time.And the secondary index included mechanical ventilation complications,hospitalization time,blood gas analysis,NICU indicators of inflammation,myocardial injury markers,and the amplitude integrated electroencephalogram(aEEG)value at 28 d and 100 d after birth.ResultsThere were 33 and 31 cases in Heliox group and control group,respectively.The OI in the Heliox group was significantly higher than the control group,and the difference was statistically significant(P=0.022).The incidence of NICU and hospitalization time,extubation time,and complications of mechanical ventilation,in the Heliox group were significantly lower than the control group,and the differences were statistically significant(P = 0.037,0.013 and 0.010).There were statistical differences in the blood gas analysis index(pH,HCO3 1,BE,PaO2,Pa CO2)at 2,6,12 24,48 h after respiratory support between the two groups(P < 0.05);the inflammation makers(IL-6,IL-8,TNF-,CRP)at 6 h and myocardial injury markers(CK,CK-MB)at 24 h after respiratory support in the Heliox group were decreased when compared with before respiratory support,and the differences were statistically significant(P < 0.05).The incidence rate of aEEG at 28 d and 100 d in the Heliox group was 9.1% and 3%,respectively,which was significantly lower than that of control group(25.8%,9.6%)(P < 0.05).Conclusion1.Heliox and airox combined with synchronized intermittent mandatory ventilation in the treatment of meconium aspiration syndrome can improve hypoxemia and hypercapnia in children,also improve pulmonary ventilation and lung ventilation,and has a good clinical curative effect.2.Synchronized intermittent mandatory ventilation combined with inhalation of heliox have more advantages in treatment for infants with meconium aspiration syndrome,which can significantly shorten the extubation time and hospitalization time,and reduce lung injury in infant.3.The incidence of complications of mechanical ventilation in the Heliox group was significantly lower than that in the airox group,indicating that the use of synchronized intermittent mandatory ventilation combined with heliox inhalation could reduce its damage on lungs.4.The blood gas analysis indicates that Heliox inhalation can significantly improve the efficiency of carbon dioxide removal,and reduce the hypercapnia.5.Compared with the control group,the myocardial enzymes lower in the Heliox group,and Heliox has the effect of protecting heart in ischemia reperfusion.6.Compared with the control group,inflammatory reaction index((IL-6,IL-8,tnfalpha,CRP)lower in the Heliox group,Heliox treatment can effectively reduce inflammation of lung damage,have anti-inflammatory effect.7.The aEEG examination results show that the neurodevelopmental severity incidence was higher than that of the experimental group,and that using the mixed gas SIMV combined with helium oxygen can reduce the incidence of complications,and patients had good tolerance and stable vital signs during the application process.We believe that SIMV inhalation of Heliox in the treatment of neonatal MAS has better effect than air oxygen mixture,and it is safe and worthy of further study.