Neontal respiratory distress syndrome (RDS) remains a major cause of death in VLBW infants. In the pathophysiologic point of view, intra-tracheal administration of exogenous pulmonary surfactant into the baby's lung is a reasonable approach to
replenish
the missing surfactant. Although exogenous surfactant replacement therapy has already been in use in Korea, there were a few studies of those including efficacy, toxicity, safety, dosage or preparation. We assessed the efficacy and safety of
exogenous
pulmonary surfactant by a randomized controlled trial.
Study population was made up of newborn infants who were diagnosed as severe RDS and admitted to our NICU from June 1990 till Dec. 1992. They were weighing 500 to 1,500 gm and receiving assisted ventilation with 70 percent or more oxygen and with
7cmH O
or more of mean airway pressure. Single postventilatory dose of exogenous surfactant (120mg of phospholipid per kilogram of body weight [4ml per kilogram] of Surfacten(r) or 100mg of phosphlipid per kilogram of body weight ([4 ml per kilogram] of
Survanta(r)) was administered into the trachea in 5 split dose with position change within 8 hours of birth in 18 babies (13 Surfacten(r)/5 Survanta(r)). The same number of preterm babies with severe RDS, who received intermittent mandatory
ventilation
only, were randomly assigned to the control group.
Mean birth weight (1,073 gm) and mean gestatioal age (28.1 wk) of the treated group were not different statistically from those of the control group; And we could not find statistic differences in other pretreatment characteristics between the
group
such as sex, multiple gestation, Apgar score, and perinatal complications. Onset of surfactant administration was mean 4.2 hours (2.0~7.5 hour) postnatally. Treatment with Surfacten(r) resulted in a significant improvement of oxygenation
(reduction
in
fractional inspiratory oxygen concentration, increased in ratio of arterial to alveolar oxygen tension) and reduction of ventilator requirement (decreased in mean airway pressure and ventilatory index). But these significant effects were
short-term
and
transient. In cases of Survanta(r) -treated group, these responses were less prominent, but we couldn't perform statistic analysis because of small sample size. Initial significant improvement with a lasting response was shown in 6 babies,
initial
transient effect following worsening to eventual death was found in 4, and no response was found in 3. Periventicular-intraventricular hemorrhage (12 vs 9) and patent ducts arteriosus (10 vs 6) were more frequent among the infants treated with
surfactant than in the control group, and penumothorax (1 vs 4) and pulmonary interstitial emphysema (3 vs 6) were less frequent, but they were not statistically significant. Interestingly, the incidence of sepsis was significantly higher in the
surfactant-treated group than in the control group (9 vs 5; p-value=0.05). There were no significant differences between the group with respect to the frequencies of bronchopulmonary dysplasia (5 vs 3) and retinopathy of prematurity (3 vs 4).
There
were
7 neonatal deaths (54%) in the surfactant-treated group and 6(46%) in the control group, that was not statistically significant. No statistical differences were noted in the duration of ventilator care (34 vs 40 days; p-value=0.02), oxygen
therapy
(38
vs 47 days; p-value=0.92) and hospital days (105 vs 79 days; p-value=0.17).
We concluded that exogenous surfactant replacement therapy reduces the severity of RDS during early period of treatment, but not reduces long-term complications or neonatal mortality.
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