Comparison of Surfacten Versus Newfacten for the Treatment of Respiratory Distress Syndrome

PURPOSE: This study was undertaken to determine the comparative efficacy between Surfacten and Newfacten in the early course of respiratory distress syndrome, ventilatory parameters, mortality and complications of RDS. METHODS: For the period of March 1998 to August 1999, total 60 neonates with RDS were treated with Surfacten (n=30) or Newfacten (n=30) at 2 different hospitals. Patients were enrolled for the trial if the following criteria were met; (1) age less than 24 hours; (2) birth weight between 800 gm and 2,500 gm; (3) clinical and radiographic findings consistent with RDS; (4) respiratory distress severe enough to require endotracheal intubation and mechanical ventilation; (5) a written informed consent by a parent. Infants were not eligible if they had a congenital anomaly or proven chromosomal anomaly. Two groups were treated with the equal doses of Surfacten and Newfacten via identical method and the various ventilator parameters, mortality and complications of RDS were compared. RESULTS: Surfacten was administered at 5.8 5.5 hour after birth and Newfacten was administered at 5.9 5.4 hour after birth. There were no differences in birth weight, gestational age in between 2 study groups. Ventilator parameters such as FiO2, MAP, VI, a/APO2 were measured in both groups and the differences were not statistically significant. There were no differences in the incidence of BPD, PDA, IVH, NEC, pneumothorax, pulmonary hemorrhage and ROP between two groups. There were no differences in mortality, the duration of ventilator care, and oxygen therapy between two groups. CONCLUSION: The effectiveness of Newfacten was comparable to that of Surfacten in terms of its efficacy in the treatment of RDS, complications, and mortality.

Clinical Trial of Domestically Developed Bovine Lung Surfactant YY-38 in Neonatal Respiratory Distress Syndrome

PURPOSE: We previously reported modified bovine lung surfactant YY-38(Newfactan ) had a low surface tension, good hysteresis, and exhibited good pressure-volume curve in animal experiment(J Korean Pediatr Asso 1997;40:771-85). We performed multicenter clinical trial of Newfactan in neonatal RDS. METHODS: Seventy-seven infants with RDS(GA 31.8+/-2.9 wks and BW 1,809+/-592 gm) in 4 NICU were enrolled. After administration of Newfactan , we analyzed ventilator parameters and outcomes in 71 infants excluding mortality cases(n=6), and also compared risk factors between response(n=53) and redosing group(n=18). RESULTS: Newfactan was administered at 6.8+/-7.2 hr after birth. Ventilator parameters such as FiO2, alveolar-arterial oxygen difference(a-A PO2) and oxygenation index(OI) except mean airway pressure(MAP) were significantly improved from six hours after administration. All parameters were improved at 24 hours after administration and persisted for 5 days. Outcomes were as follows; PDA(n=24), BPD(n=16), IVH(n=13), sepsis(n=9), ROP(n=7), pneumothorax(n=4) NEC(n=3), PIE(n=2), and pulmonary hemorrhage(n=1). All patients survived 30 days after birth. Redosing rate was 25%. The incidence of PDA was greater in redosing(56%) than in response group(26 %)(P=0.025). CONCLUSION: In prospective multicenter clinical trial, Newfactan was effective in the treatmentof RDS.

Physical and Biological Activity of Domestic Product of Modified Bovine Lung Surfactant

PURPOSE: Neonatal respiratory distress syndrome is caused by the deficiency of lung surfactant in premature babies. For the treatment of RDS at present surfactants such as Surfacten (Tokyo-Tanabe Co., Japan) and Exosurf (Wellcome Co., USA) are used. As awarded the grant from the Ministry of Science and Technology for a model research project of Medium-Technology program, we have modified (supplemented) the bovine lung extracts to get YY-38, for which we have performed physical and biological activities. METHODS: For physical properties, we performed stable microbubble test (SMR) and measured surface tension lowering activity using a pulsating bubble surfactometer. Minimum and maximum surface tensions measured at 1 and 5 minutes gave surface tension-surface area diagrams, from which compressibility at surface tension 10mN/m was also calculated. As to the biological activity, we used premature rabbit fetuses as a model for the study of pressure-lung volume relationship. The lung pathology was examined on the lung tissues subsequently obtained, and aerated area ratios were calculated based on the area measured by an image analyzer. RESULTS: The minimum surface tensions of YY-38 at 1 and 5 minutes for all different concentrations were low at 10mN/m, while the maximum surface tensions ranged from 33.01mN/m to 41.07mN/m. The surface tension-surface area curve showed a definite hysteresis at 1 and 5 minutes for all concentrations, and the surface tension fell below 10mN/m with 20% surface area compression. The compressibilities at surface tension 10mN/m at 5minutes for all concentrations were all below 0.02. In animal experiments, the mean lung volume of premature rabbit fetuses was inflated to 80.9ml/kg at maximum 30cmH2O, while the lung volume was maintained at 38.3mg/kg when the lung was deflated to 5cmH2O. The overall aerated area ratio was 45.4%. CONCLUSIONS: YY-38 formed sufficient amount of stable microbubbles and had a surface tension low enough to maintain alveolar stability and to exhibit a good hysteresis curve. In animal experiments it helped the expansion of premature lungs during inspiratory phase and was effective in the prevention of collapse during expiratory phase.