[Nasal continuous positive airway pressure ventilation in children with community-acquired pneumonia under five years of age: a prospective, multi-center clinical study]

Objective: To analyze the clinical characteristics of community-acquired pneumonia (CAP) in children under five years of age and analyze the safety and efficiency of nasal continuous positive airway pressure (NCPAP) ventilation for CAP in this population. Method: This was a prospective multicenter study. Children who were admitted to these six centers with CAP and met the NCPAP ventilation indications, aged from 29 d to 5 years, were continuously included during November 2013 to October 2015. The baseline data were collected and NCPAP ventilation were then followed up by operation standards, and the vital signs and arterial blood gas change at special time points were observed and recorded. Any side effect associated with NCPAP were recorded. For categorical variables, comparisons were performed using Fisher test. Rank-sum test and t test were performed respectively for abnormal and normal distribution continuous variables. The variables pre-NCPAP and post-NCPAP were analyzed by repeated measures ANOVA analysis. Result: Totally 145 children were included, and 13 children were excluded due to incomplete data. One hundred and two children(77.3%)were ≤12 months; 91 children (68.9%) were from rural area. NCPAP ventilation was effective in 123 children, with a response rate of 93.2%, were all discharged with a better condition; it was ineffective in 9 children(6.8%), and they were all intubated and went on mechanical ventilation, 5 were discharged with a better condition, and 4 died after gaving up treatment. The gender, age, body weight, residence, main symptoms, main signs, imaging diagnosis, medications, partial pressure of oxygen(PaO(2)), breath and heart rate before NCPAP treatment of two groups had no significant differences(allP>0.05). The rates of combining underlying diseases, trouble with feeding and cyanosis, and the partial pressure of carbon dioxide(PaCO(2) ) before NCPAP ventilation were higher in NCPAP ineffective group ((59±11 )vs.( 49±11) mmHg, 1 mmHg=0.133 kPa, t=-2.597, P=0.028); while the PaO(2)/fraction of inspiration O(2) (FiO(2) ) before NCPAP was lower((150±37) vs. (207±63) mmHg, t=2.697, P=0.008). The breathing, heart rate and PaCO(2) of NCPAP effective group decreased significantly, while the PaO(2) and PaO(2)/FiO(2) increased significantly after 2, 8, 24 h of NCPAP ventilation(all P=0.000). PaCO(2) in children with hypercapnia before NCPAP ventilation in NCPAP effective group decreased significantly ((48±9), (47±12), (45±11)vs.(58±7)mmHg, all P=0.000). All children tolerated well to NCPAP ventilation, and there were no severe side effects or complications associated with NCPAP ventilation. Conclusion: NCPAP ventilation is safe and effectively improved the oxygenation and hypercapnia in infants with CAP. But it may not work well in children with underlying diseases, manifest as difficulty in feeding/cyanosis and extremely high PaCO(2) or low PaO(2)/FiO(2), and they may need early intubation.