Clinical Study On High Frequency Oscillation Ventilation In The Treatment Of Neonatal Respiratory Distress Syndrome

Background and ObjectiveNeonatal respiratory distress syndrome(NRDS) is a common complications of premature infants and seriously affect the survival rate and the quality of life in premature infants. The smaller the gestational age, the higher the incidence of NRDS. NRDS is due to the lack of pulmonary surfactant(PS) shortly after birth that results in progressive respiratory distress and respiratory failure,mainly seen in preterm infants premature. PS combined CPAP greatly reduce the cases who must use mechanical ventilation, but there are still some critical cases need mechanical ventilation support. It is reasonable that we choose mechanical ventilation way can effectively improve the survival rate of NRDS. High frequency oscillatory ventilation(HFOV) as a form of mechanical ventilation is in the form of small tidal volume and high frequency ventilation. It is mainly used for the treatment of neonatal intensive respiratory failure, with its special mechanism of ventilation and good curative effect, in NRDS therapy has the potential of increasing application. But it is different from normal ventilation way, often used after a failed rescue medications. In several large multicenter, effectiveness and safetyof HFOV for the present clinical results are not consistent, so we need to do further clinical test and verify whether or not. Through comparative analysis of blood gas, ventilation parameters and clinical outcomes which are from SIMV and HFOV for the treatment of NRDS, we need to evaluate the efficacy and safety of HFOV, discuss whether there are further promotes in clinical application of this new type of ventilation mode.Methods1. Object: From January 2012 to December 2013 RDS children treated in neonatology of Anhui Provincial Chilgren’s Hospital.NRDS diagnosis standard reference of 4th Practical neonatology. Inclusion criteria:(1) birth gestational age was less than 36 + 6 weeks;(2) infants need mechanical ventilation;Exclusion criteria:(1) severe asphyxia;(2) serious malformation(severe congenital heart disease, diaphragmatic hernia, cleft palate, etc;(3) severe infection;(4) shock;(5) less than 24 h or giving up treatment. Infants were randomly divided into HFOV group or SIMV group.2 Basic line: There were total 96 infants with mechanical ventilationd uring the same period, 56 cases were randomly divided into two groups: HFOV group and SIMV group. Mechanical ventilation in HFOV group less than 24 h and give up 5 cases, finally complete 23 cases, 20 were male, 3 were female, patients with gestational age(32.8 ± 3.0) w(28.5 ~ 36.6 w), birth weight(1.83 ±0.61) kg(0.87 ~ 3.05 kg), 3 cases died; Mechanical ventilation in SIMV group less than 24 h and give up 3 cases, complete 25 cases, 22 were male, 3 were female, gestational age(32.7 ± 2.1) w(28.1 ~ 36.5 w), birth weight(1.79 ±0.48) kg(0.90 ~ 3.12 kg), 4 cases died. There was no statistically significant difference between two groups of infants with basic situation.3. The general treatment: The general treatment of two groups’ infants with the same treatment, including heat preservation, maintain a stable internal environment, nutritional support, prevention and treatment of infection, some children use dopamine activity such as cardiovascular drugs guarantee the stability of cardiovascular function. Within one day all infanta must use PS,100-200 mg/kg. It can be repeated using if the illness needs.4 Mechanical ventilation: SIMV group choose Siemens Sevrio machine. HFOV group choose Stephnie machine.Target blood gas value is Sp O2 88% ~ 95%, Pa CO2 35 ~ 50 mm Hg(1 mm Hg = 0.133 k Pa), two groups of infants according to the Sp O2 by adjusting the parameters of the machine. When the machine parameters was low enough and the clinical symptoms improved that can withdraw the machine. If necessary, CPAPcan be used after extubation.5. Monitoring indicators: We monitor these indicators such as blood pressure, heart rate, breathing, Sp O2, PS concrete application situation. Blood gas values of infants in 1,6,12,24 hour after ventilation were recorded; At the same time record Fi O2, MAP, and oxygen index(OI). The occurrence of complications, such as lung gas leakage(PAL), pulmonary hemorrhage(PNH), late record the number of cases of bronchial pulmonary dysplasia(BPD).Regular head examination, cardiac ultrasound to find out intracranial damage(IVH and PVL), premature retinopathy(ROP), continuous pulmonary hypertension(PPHN); The time of mechanical ventilation and hospital stay wew recorded in two groups.6. Statistical analysis: The data were analyzed by SPSS 13.0 software. Measurement data was described by mean ±standard( x ±s). Statistical methods include repeated measurement variance, independent samples t-test between the two groups. Applicate Bonferroni test in different point when ventilating with different groups. Count data by chi-square test or Fisher’s exact probability method. P<0.05 means the difference is statistically significant.Results1. The basic situation.It was total 96 children with NRDS using mechanical ventilation in the same period.There is 56 cases into the randomized trial. Less than 24 h and give up 5 cases in HFOV group.Finally complete 23 cases, 3 cases died; Less than 24 h and give up 3 cases in SIMV group. Finally complete 25 cases, 4 cases died.There was no statistically significant difference after statistics analysis between the two groups of children with basic situation.It was comparable.2. The influence on the PS. The average use of PS was fewer in HFOV group than in SIMV group, the differences between the two groups have statistical significance(P < 0.05), The number of repeated cases in HFOV group is less than in SIMV group, but there was no statistically significant difference(P > 0.05).3. There was no statistically significant difference in Blood gas index and respiratoryparameters comparison treatment before ues ventilation. The curative effect is distinct. Pa O2 increase significantly, FIO2, Pa CO2, OI dropped significantly in two groups.Difference of Fi O2, OI was statistically significant(P < 0.05) at 6, 24 hours after mechanical in differente groups. Differences of the MAP persist(P < 0.05);There is no statistical significance with Pa CO2 in different mechanical ventilation(P > 0.05).4. The outcomes and complications. The rate of pulmonary air leak and bronchopulmonary dysplasia in the HFOV group is the same with which in SIMV group(P>0.05). Other complications also showed no significant difference(P>0.05). Cure rate in the two groups was no significant difference(P>0.05).Therw are statistically significant with mechanical ventilation time and the time in haspital between the two groups(P < 0.05).ConclusionThese results show that HFOV ventilation can reduce consumption of PS, decrease Pa CO2 and fraction of inspiratory oxygen. It also can improve Pa O2 effectively and significantly.It is quickly to relieved the symptoms of hypoxia and aerobic concentration.HFOV has a better pulmonary oxygenation than that of SIMV in improving oxygenation function.It is an effective and safe ventilation mode.It does not increase the incidence of intracranial hemorrhage,pulmonary hemorrhage or other complications.It has the more value in clinical application.