Use of surfactant for prophylaxis versus rescue treatment of respiratory distress syndrome: experience from an Italian-Bulgarian trial.
To show if surfactant applied in different social-sanitary realities as prophylaxis of respiratory distress syndrome (RDS) is equally useful and able to reduce mortality and incidence of 3-4 radiological grade RDS.
                Two neonatal intensive care units (NICU) in Italy, one NICU in Bulgaria and one NICU in Romania were involved in a randomized controlled clinical trial of prophylaxis vs rescue treatment of RDS. Babies with gestational age 26-30 wks were randomized before birth to prophylaxis in the delivery-room with 200 mg/kg of porcine surfactant (prophylaxis) or to routine assistance (control). Subsequently the babies developing RDS requiring mechanical ventilation and fraction of inspired oxygen (FiO2) > or = 0.4 to maintain PaO2 about 50 mmHg were allowed to be treated rescue with 200 mg/kg of the same surfactant. To reach end-points of reducing mortality by 40% and incidence of radiological grade 3-4 RDS a total number of 174 patients were required.
                Due to logistic, practical and social-political problems the study was interrupted after enrollment of 93 babies (61 in Italy and 32 in Bulgaria). The Romanian centre did not start the study because it was impossible in the scheduled times to equip it for mechanical ventilation of the newborn infants. Analysis done on an intention to treat basis did not show significant reductions of mortality and 3-4 radiological grade RDS, even if there was a trend towards a reduction in the babies given prophylaxis. A significantly lower number of babies given prophylaxis required a subsequent rescue treatment compared to controls (p < 0.001). There was no difference in other complications such as intraventricular haemorrhage, air-leak syndromes and infections between prophylaxis and control infants. As regards pulmonary gas exchange, the PaO2/FiO2 ratio was significantly improved in the babies given prophylaxis for the first 12 hours of life vs the controls.
                Even if the study was terminated before term, the analysis of the data shows that prophylaxis with surfactant is equally effective in different social-clinical conditions to improve pulmonary gas-exchange, especially in the first critical hours of life of premature babies.
There is insufficient information on the use of rescue HFOV to make recommendations for practice. The small amount of data that exists suggest that harm might outweigh any benefit. Any future use of HFOV as rescue therapy for preterm infants with severe RDS should be within randomised controlled trials and address important outcomes such as longer term pulmonary and neurological function.