[Protective and curative effects of prophylactic administration of pulmonary surfactant on neonatal respiratory distress syndrome].

OBJECTIVE

To evaluate the protective and curative effects of prophylactic administration of pulmonary surfactant (PS) on neonatal respiratory distress syndrome (NRDS).

METHODS

One hundred neonates aged 0.5 h after birth, with the gestational age < 32 w, birth weight < 1500 g, and number of gastric, stable microbubble < or = 7/mm(2) by gastric stable microbubble test (SMT), but without clinical or radiological manifestations of RDS at the admission, were randomly divided into 2 equal groups: prophylactic group (PG), receiving curosurf, a product of PS, immediately after admission; and non-prophylactic group (N-PG), receiving curosurf only after development of RDS.

RESULTS

One hour after the administration of PS, the PaO(2), a/APO(2), pH, and PaO(2) of the PG group were 86.2 mm Hg +/- 8.1 mm Hg, 0.30 +/- 0.04, 7.38 +/- 0.06, and 178 +/- 37, all significantly higher than those of the non-PG group (all P < 0.01), and the PaCO(2) of the PG group was 37.3 mm Hg +/- 9.8 mm Hg, significantly lower than that of the non-PG group (53.6 mm Hg +/- 11.1 mm Hg, P < 0.01). In comparison with the level before the administration of PS (0.75 +/- 0.06), the level of FiO(2) of the 47 pediatric patients receiving mechanical ventilation decreased after the administration of curosurf time-dependently, e.g., was 0.50 +/- 0.09, 0.34 +/- 0.06, and 0.25 +/- 0.07 8, 48, and 96 hours after the administration. In comparison with the level before the administration of curosurf 9.0 +/- 1.0 cm H2O, the level of mean airway pressure (MAP) decreased time-dependently after the administration, e.g., were 7.5 +/- 0.8 and 6.0 +/- 0.3 48 and 96 hours after the administration (all P < 0.01). Compared with that before the administration of curosurf (3.02 +/- 0.2), the X-ray chest score decreased time-dependently after the administration of curosurf, e.g., were 1.89 +/- 0.34, 1.82 +/- 0.33, and 1.17 +/- 0.42 6, 12, and 72 hours after the administration (all P < 0.01). The RDS rate of the PG group was 30%, significantly lower than that of the non-PG group (P < 0.01). The severe case rate of the PG group was 20%, significantly lower than that of the N-PG group (53%, P = 0.01). The mortally of the PG group was 0, significantly lower than that of the non-PG group (P < 0.05). The total times of supplemental oxygen administration, assisted ventilation and hospitalization of the 47 patients with RDS in the PG group were significantly shortened compared with the RDS patients in the N-PG group [(3.6 +/- 1.7) d vs. (5.9 +/- 3.6) d, P < 0.05; (8.6 +/- 5.5 d vs. (14.1 +/- 6.2) d, P < 0.01; and (20.5 +/- 10.0) d vs. (32.8 +/- 17.8) d, P < 0.05).

CONCLUSION

Prophylactic administration of PS to the preterm neonates with high risk of RDS effectively decreases the incidence of RDS, development of severe cases and mortality, shorten the disease course, the duration of supplemental oxygen administration and assisted ventilation, thus decreasing the potential morbidity associated with long-term oxygen supplement and assisted ventilation.