Respiratory Support Technology In The Treatment Of Late Preterm Clinical Observation Of Respiratory Failure

Objective To evaluate clinical characteristics, efficacy and complications of late preterm infants with respiratory support because of hypoxic respiratory failure.Methods Late preterm infants with hypoxic respiratory failure were selective used continuous positive airway pressure (CPAP), conventional mechanical ventilation (CMV) or high-frequency mechanical ventilation (HFV) and implemented lung protective ventilation strategy. Before respiratory support and after6h,12h,24h,48h,72h of the treatment performed blood gas analysis, recorded modes and parameters (PIP, MAP, FiO2, PEEP) of ventilation, hospital stay of the infants surviving, complications and mortality in72hours. Performed cranial ultrasonography and echocardiography on4-7days after birth, observation of intracranial hemorrhage, periventricular leukomalacia, the incidence of BPD.Results There were84late preterm infants with respiratory support,43cases (48.7%) were neonatal respiratory distress syndrome (NRDS),23cases of whom were used PS, accounting for27.3%. On gestational age34weeks,35weeks and36weeks, the duration of ventilation were (87.80±46.34)h,(79.75±33.02)h and (60.75±23.25)h, respectively. The difference was statistically significant (F=4.951, P=0.010). By further pairwise comparison, there were statistically significant (P=0.018,0.010and0.002, respectively). FiO2>0.6were (13.70±18.99)h,(7.76±13.94)h and (2.10±4.61)h, respectively. The difference was statistically significance (F=2.957, P=0.048). By pairwise comparison, differences were statistically significant (P=0.013,0.018,0.031).54patients (61.6%) were used CPAP therapy, of whom17cases (31.4%) turned to CMV. Conventional mechanical ventilation were51cases,9cases of which turn to HFV. High-frequency mechanical ventilation (HFV) were12cases. The duration of ventilation were (50.58±16.78)h,(88.57±39.01)h and (103.10±35.14)h. The application time of CPAP was shorter than CMV or HFV. After6h of treatment, FiO2, PaO2, PaO2/FiO2, PaCO2, A-aDO2and a/A values were significantly improved,0.41±0.12,(85.14±25.45)mmHg,231.21±87.22,(41.95±10.456)mmHg,(119.49±75.67)mmHg and0.39±0.14. respectively. After12h,24h,48h,72h, the results were further improved and maintained relatively stable. Compared with pre-treatment, the differences we statistically significant. Mortality was12cases, accounted for13.6%。 The incidences of pneumonia, abnormal ultrasonography and PDA in CMV and HFV group had not statistically significant (P>0.05). There was no pneumothorax in HFV, but4cases in CMV group.Conclusion The smaller the gestational age, the longer the time of needing high concentrations of oxygen and assisted ventilation. Different ventilation modes can significantly improve respiratory failure, and remained relatively stable. There was no difference in the incidence of complications. The mortality rate of late preterm infants with respiratory support remains high. Objective To explore death risk factors and prognosis of late preterm infants with mechanical ventilation who died of respiratory failure, and provide the basis for early predicting the prognosis of late preterm infants.Methods Collected88late preterm infants with hypoxic respiratory failure, who admitted to NICU betweem January2010and September2011and required mechanical ventilation. Inclusion criteria:gestational age≥34week but≤37week, severe respiratory failure requiring mechanical ventilation and the expected duration of mechanical ventilation≥24hours; exclusion criteria:congenital pulmonary malformations, the existence of one or more consider life-threatening congenital anomalies. Before mechanical ventilation and after6h,12h,24h of the treatment, preforned arterial blood gas and recorded the changes of ventilator parameters and prognosis. Divided into the death group and survival group.Results12cases (13.6%) died. The median birth weight of death group was1975g, and the survival group was2500g. The difference had statistically significant. Median gestational age of the death group was34weeks, prenatal hormone (completely) and application of PS were2patients (16.7%) respectively. But the differences had not statistically significant (χ2=0.379, P=0.773). The median duration of FiO2>60%of death group was30h, the median of minimum PaO2, minimum a/ADO2and minimum PaO2/FiO2were39.5mmHg,0.12and83.03mmHg, respectively. The median maximum FiO2was80%. The median maximum A-aDO2was320mmHg. Compared with the survival group, The differences were statistically significant. Further logistic regression analysis, independent risk factors were birth weight and maximum A-aDO2. The regression coefficients were-0.004and-0.013. OR values were0.996and1.013, respectively. ROC analysis of the ability of A-aDO2predicting prognosis showed the area under curve (AUC) was0.787. The difference was statistically significant (P=0.002) compared with0.5, the index of the cut-off point A-aDO2=350mmHg corresponded to the maximum(0.532) prediction effect.Conclusions Independent risk factors of died from respiratory failure were birth weight and maximum A-aD02. A-aDO2=350mmHg was the best prediction accuracy.