Aerosolized Calfactant for Newborns With Respiratory Distress: A Randomized Trial.

BACKGROUND: Exogenous surfactants to treat respiratory distress syndrome (RDS) are approved for tracheal instillation only; this requires intubation, often followed by positive pressure ventilation to promote distribution. Aerosol delivery offers a safer alternative, but clinical studies have had mixed results. We hypothesized that efficient aerosolization of a surfactant with low viscosity, early in the course of RDS, could reduce the need for intubation and instillation of liquid surfactant. METHODS: A prospective, multicenter, randomized, unblinded comparison trial of aerosolized calfactant (Infasurf) in newborns with signs of RDS that required noninvasive respiratory support. Calfactant was aerosolized by using a Solarys nebulizer modified with a pacifier adapter; 6 mL/kg (210 mg phospholipid/kg body weight) were delivered directly into the mouth. Infants in the aerosol group received up to 3 treatments, at least 4 hours apart. Infants in the control group received usual care, determined by providers. Infants were intubated and given instilled surfactant for persistent or worsening respiratory distress, at their providers' discretion. RESULTS: Among 22 NICUs, 457 infants were enrolled; gestation 23 to 41 (median 33) weeks and birth weight 595 to 4802 (median 1960) grams. In total, 230 infants were randomly assigned to aerosol; 225 received 334 treatments, starting at a median of 5 hours. The rates of intubation for surfactant instillation were 26% in the aerosol group and 50% in the usual care group (P < .0001). Respiratory outcomes up to 28 days of age were no different. CONCLUSIONS: In newborns with early, mild to moderate respiratory distress, aerosolized calfactant at a dose of 210 mg phospholipid/kg body weight reduced intubation and surfactant instillation by nearly one-half.

Antiinflammatory Effects of Budesonide in Human Fetal Lung.

Lung inflammation in premature infants contributes to the development of bronchopulmonary dysplasia (BPD), a chronic lung disease with long-term sequelae. Pilot studies administering budesonide suspended in surfactant have found reduced BPD without the apparent adverse effects that occur with systemic dexamethasone therapy. Our objective was to determine budesonide potency, stability, and antiinflammatory effects in human fetal lung. We cultured explants of second-trimester fetal lung with budesonide or dexamethasone and used microscopy, immunoassays, RNA sequencing, liquid chromatography/tandem mass spectrometry, and pulsating bubble surfactometry. Budesonide suppressed secreted chemokines IL-8 and CCL2 (MCP-1) within 4 hours, reaching a 90% decrease at 12 hours, which was fully reversed 72 hours after removal of the steroid. Half-maximal effects occurred at 0.04-0.05 nM, representing a fivefold greater potency than for dexamethasone. Budesonide significantly induced 3.6% and repressed 2.8% of 14,500 sequenced mRNAs by 1.6- to 95-fold, including 119 genes that contribute to the glucocorticoid inflammatory transcriptome; some are known targets of nuclear factor-κB. By global proteomics, 22 secreted inflammatory proteins were hormonally regulated. Two glucocorticoid-regulated genes of interest because of their association with lung disease are CHI3L1 and IL1RL1. Budesonide retained activity in the presence of surfactant and did not alter its surface properties. There was some formation of palmitate-budesonide in lung tissue but no detectable metabolism to inactive 16α-hydroxy prednisolone. We concluded that budesonide is a potent and stable antiinflammatory glucocorticoid in human fetal lung in vitro, supporting a beneficial antiinflammatory response to lung-targeted budesonide:surfactant treatment of infants for the prevention of BPD.

Pharmacokinetics of Budesonide Administered with Surfactant in Premature Lambs: Implications for Neonatal Clinical Trials.

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of premature human infants, which may persist through adulthood. Airway inflammation has been firmly established in the pathogenesis of BPD. Previous studies to reduce airway inflammation with high-dose dexamethasone demonstrated adverse neurological outcomes, despite lower incidences of BPD. Instillation of budesonide and surfactant can facilitate early extubation and reduce the incidence of BPD and death among very low birth weight infants. However, the pharmacokinetics of budesonide and its distribution into the lung and brain are unknown. Therefore, 5 premature lambs were administered 0.25 mg/kg budesonide, with surfactant as the vehicle. Plasma and tissue samples were taken from the lambs for measurement of budesonide, 16α- hydroxy prednisolone, and budesonide palmitate using LC/MS/MS. Peak plasma budesonide concentrations were inversely correlated with the oxygenation index (correlation coefficient of -0.75). plasma budesonide concentrations were extremely low (~10% of expected) for two lambs that had high oxygenation indices and were excluded from further analyses. For the remaining 5 premature lambs, a non-compartmental analysis demonstrated an AUCinf of 148.77 ± 28.16 h*µg/L, half-life of 4.76 ± 1.79 h, and Cmax of 46.17 ± 17.71 µg/L. Using population pharmacokinetic methods, a onecompartment model with exponential residual error and first-order absorption adequately described the data. The apparent clearance and apparent volume of distribution of budesonide were estimated at 6.29 L/h (1.99 L/h/kg) and 29.1 L (9.2 L/kg), respectively. Budesonide and budesonide palmitate, but not 16α-hydroxy prednisolone, were detected in lung tissue. In this study, budesonide and its metabolites were not detected in the brain, which suggests that intratracheal instillation suggests that after local pulmonary deposition, there is no evidence of budesonide accumulation in the central nervous system. Overall, these results show that peak plasma budesonide concentrations are inversely correlated with the oxygenation index and that lung-specific delivery of budesonide avoids accumulation of budesonide in the brain.

The Adult Calfactant in Acute Respiratory Distress Syndrome Trial.

BACKGROUND: Surfactant has been shown to be dysfunctional in ARDS, and exogenous surfactant has proven effective in many forms of neonatal and pediatric acute lung injury (ALI). In view of the positive results of our studies in children along with evidence that surfactant-associated protein B containing pharmaceutical surfactants might be more effective, we designed a multiinstitutional, randomized, controlled, and masked trial of calfactant, a calf lung surfactant, in adults and children with ALI/ARDS due to direct lung injury. METHODS: Adult subjects within 48 h of initiation of mechanical ventilation for direct ARDS were randomized to receive up to three interventions with instilled calfactant vs air placebo. The primary outcome was 90-day all-cause mortality. RESULTS: Three hundred seventeen subjects were enrolled, 308 of whom could be evaluated. There were no significant baseline differences between groups. Calfactant administration was not associated with improved survival, lengths of stay, or oxygenation. Calfactant instillation was frequently associated with transient hypoxia and hypotension. The study was stopped at the first interim analysis at the sponsor's request. CONCLUSIONS: Administration of calfactant was not associated with improved oxygenation or longer-term benefits relative to placebo in this randomized, controlled, and masked trial. At present, exogenous surfactant cannot be recommended for routine clinical use in ARDS. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00682500; URL: www.clinicaltrials.gov.

The relationship of fluid administration to outcome in the pediatric calfactant in acute respiratory distress syndrome trial.

OBJECTIVES: Adult studies have demonstrated the relationship between fluid overload and poor outcomes in acute lung injury/acute respiratory distress syndrome. The approach of pediatric intensivists to fluid management in acute lung injury/acute respiratory distress syndrome and its effect on outcomes is less clear. In a post hoc analysis of our Calfactant in Acute Respiratory Distress Syndrome trial, we examined the relationship of fluid balance to in-hospital outcomes in subjects with acute lung injury/acute respiratory distress syndrome. DESIGN: Calfactant in Acute Respiratory Distress Syndrome was a masked randomized controlled trial of calfactant surfactant versus placebo in pediatric patients with acute lung injury/acute respiratory distress syndrome due to direct lung injury. Caregivers were encouraged to follow a conservative fluid management guideline based on the adult Fluid and Catheter Treatment Trial. Daily fluid balance was collected for the first 7 days after trial enrollment and correlated with clinical outcomes. PATIENTS AND SETTING: Children admitted to PICUs with acute lung injury/acute respiratory distress syndrome from 24 children's hospitals in six different countries. INTERVENTION: Post hoc analysis of daily fluid balance in subjects from the Pediatric Calfactant in Acute Respiratory Distress Syndrome trial. MEASUREMENTS AND MAIN RESULTS: Despite the conservative fluid guideline, fluid management was more consistent with a "liberal" approach. On average, study subjects accumulated 1.96 ± 4.2 L/m over the first 7 days of the trial. Subjects who died accumulated on average 8.7 ± 9.5 L/m versus 1.2 ± 2.4 L/m in survivors. Increasing fluid accumulation was associated with fewer ventilator-free days and worsening oxygenation. Multivariable regression models that included age, gender, Pediatric Risk of Mortality score, initial oxygen saturation index and PaO2/FIO2 ratio, injury category, and treatment arm failed to account for the differences in fluid management. CONCLUSIONS: Pediatric intensivists generally follow a "liberal" approach to fluid management in children with acute lung injury/acute respiratory distress syndrome. Illness severity or oxygenation disturbance did not explain differences in fluid accumulation but such accumulation was associated with worsening oxygenation, a longer ventilator course, and increased mortality. A more conservative approach to fluid management may improve outcomes in children with acute lung injury/acute respiratory distress syndrome.

Pediatric calfactant in acute respiratory distress syndrome trial.

RATIONALE: Our previous studies in children with acute lung injury/acute respiratory distress syndrome demonstrated improved outcomes with exogenous surfactant (calfactant) administration. Sample sizes in those studies were small, however, and the subject populations heterogeneous, thus making recommendations tenuous. OBJECTIVE: To investigate the efficacy of surfactant administration in a larger, more homogenous population of children with lung injury/acute respiratory distress syndrome due to direct lung injury. DESIGN AND SETTING: Masked, randomized, placebo-controlled trial in 24 children's hospitals in six different countries. PATIENTS AND METHODS: Children 37 weeks postconception to 18 years old with lung injury/acute respiratory distress syndrome due to direct lung injury were randomized to receive up to three doses of 30 mg/cm height of surfactant (calfactant) versus placebo (air) within 48 hours of intubation and initiation of mechanical ventilation. The primary outcome was mortality at 90 days. Ventilator-free days, changes in oxygenation, and adverse events were also assessed. RESULTS: The study was stopped at the sponsor's request after the second interim analysis for presumed futility. A total of 110 subjects were enrolled, with consent withdrawn from one whose data are unavailable. There were no significant differences between groups except in hospital-free days (10.4 ± 7.8 placebo vs 6.4 ± 7.8 surfactant; p = 0.01). Overall 90-day mortality was 11% (seven surfactant, five placebo). No immediate improvement in oxygenation was associated with surfactant administration. CONCLUSIONS: Surfactant did not improve outcomes relative to placebo in this trial of children with direct lung injury/acute respiratory distress syndrome. Differences in concentration of the surfactant, failure to recruit the lung during surfactant administration, or using two rather than four position changes during administration are possible explanations for the difference from previous studies. Exogenous surfactant cannot be recommended at this time for children with direct lung injury/acute respiratory distress syndrome.