To observe the clinical efficacy and safety of different doses of poractant alfa injection combined with mechanical ventilation in the treatment of children with very low body mass and neonatal respiratory distress syndrome (NRDS).

According to cohort method, children with very low body mass and NRDS were divided into control group and treatment group. On basis of mechanical ventilation, control group were treated with 100 mg·kg^-1 poractant alfa injection; treatment group were treated with 200 mg·kg^-1 poractant alfa injection. The clinical curative effect, recovery related indexes, ventilation function, blood gas indexes [partial pressure of carbon dioxide (PaCO₂), pH, partial pressure of oxygen (PaO₂)], inflammatory factors [interleukin (IL)-6, C-reactive protein (CRP)] and complications in the two groups were compared, and the safety was evaluated.

There were 43 cases in control group and 43 cases in treatment group. After treatment, there was significant difference in total response rate between treatment group and control group [93.02% (40 cases/43 cases) vs 76.74% (33 cases/43 cases), P<0.05]. After treatment, injection frequencies in treatment group and control group were (1.02±0.15) and (1.47±0.50) times, oxygen inhalation time was (90.45±7.31) and (116.72±10.24) h, mechanical ventilation time were (81.27±6.81) and (99.69±9.05) h, hospitalization time was (12.15±2.07) and (16.29±2.53) d, fraction of inspired oxygen were (36.39±4.07)% and (40.54±5.13)%, positive end-expiratory pressure were (3.64±0.53) and (4.05±0.69) cmH₂O, peak inspiratory pressure were (20.12±1.45) and (22.69±1.62) cmH₂O, PaCO₂ were (31.45±4.21) and (37.72±5.06) mmHg, pH were 7.36±0.30 and 7.21±0.27, PaO₂ were (83.46±6.45) and (78.58±5.93) mmHg, levels of serum IL-6 were (36.21±4.03) and (54.83±5.69) ng·L^-1, CRP levels were (8.03±2.11) and (11.28±3.06) mg·L^-1, and the differences were statistically significant (all P<0.05). There was significant difference in incidence of complications between treatment group and control group [9.31% (4 cases/43 cases) vs 25.57% (11 cases/43 cases), P<0.05]. The adverse drug reactions were mainly on rash, gastrointestinal dysfunction and irritability in treatment group, while which in control group were rash and gastrointestinal dysfunction. There was no significant difference in total incidence of adverse drug reactions between treatment group and control group [9.30% (4 cases/43 cases) vs 6.98% (3 cases/43 cases), P>0.05].

200 mg·kg^-1 poractant alfa injection combined with mechanical ventilation can promote the recovery of children with very low body mass and NRDS, improve ventilation function and blood gas indexes, alleviate inflammatory response and reduce complications, and the safety is good.