Respiratory distress syndrome in preterm infants of less than 32 weeks: What difference does giving 100 or 200 mg/kg of exogenous surfactant make?

BACKGROUND: Surfactant dosing and effective delivery could affect continuous positive airways pressure (CPAP)-failure. Nevertheless, information on exogenous surfactant dosing with current administration methods is limited. OBJECTIVE: To describe the effect of 100 or 200 mg/kg of surfactant as first-line treatment of respiratory distress syndrome in preterm infants of less than 32 weeks gestation. STUDY DESIGN: A retrospective single-center cohort study comparing two epochs, before and after switching from 100 to 200 mg/kg surfactant therapy. RESULTS: Six hundred and fifty-eight of the 1615 infants of less than 32 weeks were treated with surfactant: 282 received 100 mg/kg (S-100) and 376 received 200 mg/kg (S-200). There were no differences between S-100 and S-200 in perinatal data including prenatal corticosteroids, medication use, age at first surfactant administration and respiratory severity before surfactant. The S-200 vs. S-100 had fewer retreatments (17.0% vs. 47.2%, p < 0.001) and a shorter duration of oxygen therapy and mechanical ventilation (315 vs. 339 h, p = 0.018; 37 vs. 118 h, p = 0.000, respectively). There was no difference in postnatal corticosteroid use (S-200 10.0% vs. S-100 11.0%, p = 0.361). Bronchopulmonary dysplasia (BPD) was significantly lower in S-200 vs. S-100 when comparing either the 4 and 6-year periods before and after the dose switch (29.4% vs. 15.7%, p = 0.003, and 18.7% vs. 27.3%, p = 0.024, respectively) CONCLUSIONS: The switch from 100 to 200 mg/kg was associated with a marked reduction in the need for surfactant redosing, respiratory support, and BPD. This information could be important when designing a study in the modern era of less invasive administration as surfactant dosing and its effective delivery may affect the outcome.

Early nasal continuous positive airway pressure failure prediction in preterm infants less than 32 weeks gestational age suffering from respiratory distress syndrome.

BACKGROUND: Early continuous positive airway pressure (CPAP) and surfactant replacement are effective treatments for neonatal respiratory distress syndrome (RDS). CPAP is the first line in preterm infants needing respiratory support, with surfactant replacement in case of CPAP failure (CPAP-F). OBJECTIVES: To analyze incidence and factors associated with CPAP-F in preterm infants with RDS. DESIGN, SETTING AND PATIENTS: Single-center retrospective database analysis (2004-2017) of inborn infants, gestational age (GA) 24 + 0/7-31 + 6/7 weeks, not intubated on admission to the neonatal intensive care unit, managed with CPAP. CPAP-F was defined as intubation and surfactant administration in the first 72 h of life; CPAP success (CPAP-S) was CPAP alone without need for additional RDS treatments. Demographic, respiratory, and clinical data associated with CPAP-F were studied using logistic regression analysis. RESULTS: A total of 562 infants met the inclusion criteria: 252 (44.8%) were CPAP-F and 310 (55.2%) were CPAP-S. The CPAP-F, compared to CPAP-S group, had lower GA and birth weight, and were less likely to receive antenatal steroids or to be vaginal births. Logistic regression showed that the fraction of inspired oxygen (FiO2 ) ≥ 0.23 between 180 and 240 min of life (FiO2 180-240 min) was the strongest factor associated with CPAP-F (odds ratio: 16.01 [95% confidence interval: 10.34-24.81]). CONCLUSION: FiO2 180-240 min was highly predictive of CPAP-F in preterm infants. With this model for surfactant administration/CPAP-F, 11.2% of infants would have unnecessarily received treatment, but importantly, 27.7% would have been treated much earlier, with a potential reduction in air leaks and duration of mechanical ventilation.

Oxygen saturation to fraction of inspired oxygen ratio in preterm infants on routine parenteral nutrition with conventional or fish oil containing lipid emulsions.

INTRODUCTION: The benefits of intravenous (IV) fish oil (FO), as a source of n-3 long-chain polyunsaturated fatty acids, on lung growth in preterm infants, remain controversial. AIM: To evaluate if IV FO improves lung growth in small preterm infants on routine parenteral nutrition (PN). MATERIALS AND METHODS: We retrospectively reviewed prospectively collected data of preterm infants with a birth weight <1250 g who received routine PN from birth. We compared patients who received FO containing IV lipid emulsions with infants who received conventional emulsions (CNTR). The oxygen saturation (SpO2 ) to a fraction of inspired oxygen (FiO2 ) ratio (SFR) at 36 weeks (W) of gestation was chosen as the primary outcome variable to assess lung growth. RESULTS: Four hundred and seventy-seven infants were studied: 240 received IV FO and 237 CNTR. While exposure to antenatal glucocorticoids was higher in IV FO group than in CNTR (95 vs 90%, P = .04), there were no differences in birth data, enteral and parenteral nutrition intakes, ventilator supports and drug therapies. The incidence of the most common complications of prematurity at 36 W was not different (bronchopulmonary dysplasia was 27 vs 21% in IV FO vs CNTR infants, P = .1). Weight gain from birth to 36 W was marginally, but significantly, higher (+0.5 g/kg/d, P = .03) in IV FO group vs CNTR. SFR increased from 32 W to 36 W in all study patients (P < .001). IV FO infants had significantly lower SpO2 from 33 W to 35 W (P < .001) and lower (worse) SFR at 36 W (432 ± 57 vs 444 ± 51, P = .026) compared to CNTR. CONCLUSION: Contrary to our hypothesis, the use of FO containing IV lipid emulsions for the routine PN of the preterm infant did not improve lung growth compared to the infants who received conventional IV lipid emulsions.

Oxygen saturation/FIO2 ratio at 36 weeks' PMA in 1005 preterm infants: Effect of gestational age and early respiratory disease patterns.

OBJECTIVE: To assess oxygen diffusion at 36 weeks' post-menstrual age in preterm infants by means of the non-invasive oxygen saturation/fraction of inspired oxygen ratio (36w-SFR) and to identify factors associated with 36w-SFR - ie, gestational age (GA) and early respiratory disease patterns (ERP). METHODS: Retrospective analysis of prospectively collected data. SETTING: Neonatal Intensive Care Unit. PATIENTS: 1005 preterm infants born below 32 weeks' GA. INTERVENTIONS: 36w-SFR was the mean of SFR values over 24 h on the day infants reached 36 weeks' PMA. MAIN OUTCOME MEASURES: 36w-SFR. STATISTICS: descriptive statistics, univariate, and multivariate analysis to study associations of 36w-SFR, including GA and ERP. RESULTS: 36w-SFR was significantly different between infants with and without bronchopulmonary dysplasia (BPD) (371 vs 467, P < 0.001), and according to ERP (LowFIO2 466, pulmonary improvement-PI 460, pulmonary deterioration-PD 405, early persistent pulmonary deterioration-EPPD 344, P < 0.001). Significant differences were found either in BPD and in non-BPD patients according to ERP (P < 0.001). Patients without BPD had significant differences in 36w-SFR according to GA (P < 0.001), while infants with BPD and increasing GA at birth had a non-significant trend for increased 36w-SFR (P = 0.621). Factors associated with 36w-SFR were GA, being small for GA, sepsis, human milk feeding, and ERP. CONCLUSIONS: Preterm infants without BPD had a spectrum of oxygen diffusion impairment that was inversely associated with GA at birth. Infants with different patterns of ERP had significant differences in 36w-SFR.

Dosing of porcine surfactant: effect on kinetics and gas exchange in respiratory distress syndrome.

OBJECTIVE: The goal was to study exogenous surfactant disaturated phosphatidylcholine (DSPC) kinetics in preterm infants with respiratory distress syndrome (RDS) who were treated with 100 or 200 mg/kg porcine surfactant. METHODS: Sixty-one preterm infants with RDS undergoing mechanical ventilation received, within 24 hours after birth, 100 mg/kg (N = 40) or 200 mg/kg (N = 21) porcine surfactant mixed with [U-(13)C]dipalmitoylphosphatidylcholine. Clinical and respiratory parameters were recorded, and DSPC half-life and pool size and endogenous DSPC synthesis rate were calculated. RESULTS: Clinical characteristics and short-term outcomes did not differ between groups. In the 100 mg/kg group, 28 infants (70%) received a second dose after 25 +/- 11 hours and 9 (22.5%) a third dose after 41 +/- 11 hours; in the 200 mg/kg group, 6 infants (28.6%) received a second dose after 33 +/- 8 hours and 1 a third dose. The DSPC half-life was longer in the 200 mg/kg group (first dose: 32 +/- 19 vs 15 +/- 15 hours [P = .002]; second dose: 43 +/- 32 vs 21 +/- 13 hours [P = .025]). DSPC synthesis rates and pool sizes before the first and second doses did not differ between the groups. The 200 mg/kg group exhibited a greater reduction in the oxygenation index than did the 100 mg/kg group after the first (P = .009) and second (P = .018) doses. CONCLUSIONS: Porcine surfactant given to preterm infants with RDS at a dose of 200 mg/kg resulted in a longer DSPC half-life, fewer retreatments, and better oxygenation index values.