Comparison of Clinical Efficacy of Newfactan(R) versus Surfacten(R) for the Treatment of Respiratory Distress Syndrome in the Newborn Infants

Newfactan(R) is a domestically developed, bovine lung-derived, semi-synthetic surfactant. The aim of this study was to compare the clinical efficacy of Newfactan(R) with that of Surfacten(R) in the treatment of respiratory distress syndrome (RDS). Newfactan(R) or Surfacten(R) was randomly allocated to 492 newborn infants who were diagnosed as RDS and required surfactant instillation in four participating hospitals. The comparisons were made individually in two subsets of infants by birth weight (or=1,500 g group [n=239]). Short-term responses to surfactant and acute complications, such as the total doses of surfactant instilled, response type, extubation rate, ventilator settings, changes in respiratory parameters, air leak, patent ductus arteriosus, pulmonary hemorrhage, and intraventricular hemorrhage, and mortality during the 96 hr after surfactant instillation were measured. Long-term outcome and complications, such as total duration of intubation, bronchopulmonary dysplasia and periventricular leukomalacia, and ultimate mortality were measured. There were no significant differences in demographic and perinatal variables, shortterm responses to surfactant and acute complications, and long-term outcome and complications between Newfactan(R) and Surfacten(R) in both birth weight groups. We concluded that Newfactan(R) was comparable to Surfacten(R) in the clinical efficacy in the treatment of RDS in both birth weight groups.

Bilirubin Cytotoxicity in Primary Mouse Cerebral Cortical Cell Culture

PURPOSE: We sought to quantitate the cytotoxicity of bilirubin for neuronal cells at various concentrations of bilirubin and at various [bilirubin]/[albumin] ratio. METHODS: Mouse cerebral cortical cells were obtained from 15 day-old mouse fetal cerebral cortex primary culture. Cerebral cortical cells were exposed to medium containing various concentrations of bilirubin and [bilirubin]/[albumin] ratios for 4 hours. Then, the bilirubin cytotoxicity for cerebral cortical cells was quantitated by the activity of lactate dehydrogenase (LDH) released from cerebral cortical cells into the culture media and the viability of cerebral cortical cells was quantitated by MTT (3-[4, 5 dimethylthiazol-y-yl]-2, 5-diphenyl tetrazolium bromide) activity measured 4 hours after the addition of MTT labeling reagent to the cell compartment. RESULTS: At a constant [bilirubin]/[albumin] ratio of 3: 1, the increasing concentration of bilirubin (50microM, 75microM, 100microM, 150microM) resulted in proportionally increased cytotoxicity (18+/-2%, 33+/-1%, 44+/-2%, 66+/-4%, respectively). At a constant bilirubin concentration of 86microM, the increasing [bilirubin]/[albumin] ratio (1: 3, 3: 1) also resulted in proportionally increased cytotoxicity (10+/-1%, 58+/-1%, respectively) and proportionally decreased viability (83+/-1%, 65+/-2%, respectively). CONCLUSION: Not only the concentration of bilirubin, but also the [bilirubin]/[albumin] ratio may be important for the cerebral cortial cell injury by bilirubin.

Effect of Hyperbilirubinemia on the Brainstem Auditory Evoked Response in Newborn Piglets

PURPOSE: We sought to know the effect of hyperbilirubinemia on brainstem auditory evoked response in newborn piglets. METHODS: To achieve the concentration of bilirubin above 20 mg/dL, we injected a bolus of 50 mg/kg of bilirubin intravenously over 30 minutes, followed by 30-40 mg/kg/ hr of bilirubin continuous intravenous infusion to 10 newborn piglets. Brainstem auditory evoked responses were obtained from these piglets at baseline, 1 hour, 2 hours, 3 hours and 4 hours after the exposure to hyperbilirubinemia. RESULTS: The mean amplitude of wave V was 0.33+/-0.03 microV at baseline, 0.32+/-0.04 microV at 1 hour, 0.33+/-0.05 microV at 2 hours, 0.23+/-0.04 microV at 3 hours and 0.26+/-0.05 microV at 4 hours of experiment and began to decrease after 3 hours of the exposure to hyperbilirubinemia. The latency of wave III was 4.06+/-0.08 ms at baseline, 3.95+/-0.09 ms at 1 hour, 4.05+/-0.10 ms at 2 hours, 4.05+/-0.09 ms at 3 hours, 4.12+/-0.11 ms at 4 hours of experiment and began to increase after 1 hour of the exposure to hyperbilirubinemia. CONCLUSION: Hyperbilirubinemia decreased the amplitude of wave V and increased the latency of wave III of brainstem auditory evoked responses in newborn piglets.

Effects of Perfluorocarbon Associated High Frequency Oscillatory Ventilation on Hemodynamics and Gas Exchange in the Newborn Piglets with Respiratory Distress

We sought to know whether there is a further improvement in gas exchange when partial liquid ventilation (PLV) is added to high-frequency oscillatory ventilation (HFOV) in a piglet model of saline lavage-induced acute lung injury. Seven 7-9 day-old newborn piglets of mixed strain were treated with repeated saline lavage to achieve a uniform degree of acute lung injury. Then, HFOV were applied to the subject. Four animals received two consecutive doses (15 mL/kg) of perfluorodecalin at 30-min interval (PFC+HFOV group). The other three animals remained on HFOV alone (HFOV-only group). Repetitive lung lavage led to a significant acute aggravation in both gas exchange and hemodynamic parameters. Subsequent application of HFOV produced a significant rapid recovery in both gas exchange and hemodynamic parameters to near baseline levels. During and after perfluorodecalin dosing, there were no significant changes in gas exchange or hemodynamic parameters over time in both groups, and no significant differences in gas exchange or hemodynamic parameters between groups. We concluded that the addition of 30 mL/kg of perfluorodecalin to HFOV showed no detrimental effect on hemodynamics, but did not produce a significant improvement in gas exchange over a three-hour period.