The Efficacy of Surfactant Replacement Therapy in the Growth-Restricted Preterm Infant: What is the Evidence?

Nasal intermittent positive pressure ventilation as a rescue therapy after nasal continuous positive airway pressure failure in infants with respiratory distress syndrome

OBJECTIVE

Evaluate whether nasal intermittent positive-pressure ventilation (NIPPV) as rescue therapy after initial nasal continuous positive airway (NCPAP) failure reduces need for invasive mechanical ventilation (IMV) in infants with respiratory distress syndrome (RDS).

DESIGN

Retrospective cohort involving 156 preterm infants who failed initial NCPAP and were then submitted to NIPPV rescue therapy and classified into NIPPV success or failure, according to need for IMV.

RESULT

Of all infants included, 85 (54.5%) were successfully rescued with NIPPV while 71 (45.5%) failed. The NIPPV success group had significantly lower rates of bronchopulmonary dysplasia, peri/intraventricular hemorrhage, patent ductus arteriosus and greater survival without morbidities (all p ≤ 0.01). Infants who failed NIPPV had earlier initial NCPAP failure (p = 0.09). In final logistic regression model, birthweight ≤1000 g and need for surfactant remained significant factors for NIPPV failure.

CONCLUSION

NIPPV rescue therapy reduced the need for IMV in infants that failed NCPAP and was associated with better outcomes.

Comparative efficacy of pulmonary surfactant in respiratory distress syndrome in preterm infants: a Bayesian network meta-analysis

Introduction

The comparative efficacy of pulmonary surfactant in the treatment of respiratory distress syndrome in preterm infants remains unclear. We aimed to evaluate the effectiveness of different pulmonary surfactant in the treatment of respiratory distress syndrome in preterm infants and to provide an evidence-based reference for clinical use.

Material and methods

MEDLINE, Embase, The Cochrane Library, and Clinical Trials databases were electronically searched from inception to January 2019. Two reviewers independently screened literature and extracted data, and then R and RevMan 5.3 software packages were used to perform network meta-analysis.

Results

The relative risk of respiratory distress syndrome in preterm infants associated with six different pulmonary surfactant was analysed, including beractant (Survanta), surfactant A (Alveofact), calfactant (Infasurf), poractant (Curosurf), lucinactant (Surfaxin), and colfosceril (Exosurf). Patients with the following drugs appeared to have significantly reduced mortality of respiratory distress syndrome compare with beractant: surfactant A (OR = 0.53, 95% CI: 0.31-0.90), calfactant (OR = 0.91, 95% CI: 0.85-0.97), poractant (OR = 0.72, 95% CI: 0.67-0.77), lucinactant (OR = 0.80, 95% CI: 0.71-0.90), and colfosceril (OR = 0.93, 95% CI: 0.87-0.99). The SUCRA (surface under the cumulative ranking) values for each of the drugs were: beractant (8.9%), surfactant A (93.8%), calfactant (40.3%), poractant (65.4%), lucinactant (59.8%), and colfosceril (31.6%).

Conclusions

Compared with beractant, other pulmonary surfactants are more effective to reduce the mortality of respiratory distress syndrome in preterm infants. Surfactant A drugs appeared to have the best efficacy in reducing mortality of respiratory distress syndrome in preterm infants.

Fetal growth restriction is associated with an altered cardiopulmonary and cerebral hemodynamic response to surfactant therapy in preterm lambs

BACKGROUND

Efficacy of surfactant therapy in fetal growth restricted (FGR) preterm neonates is unknown.

METHODS

Twin-bearing ewes underwent surgery at 105 days gestation to induce FGR in one twin by single umbilical artery ligation. At 123-127 days, catheters and flow probes were implanted in pulmonary and carotid arteries to measure flow and pressure. Lambs were delivered, intubated and mechanically ventilated. At 10 min, surfactant (100 mg kg^-1) was administered. Ventilation, oxygenation, and hemodynamic responses were recorded for 1 h before euthanasia at 120 min. Lung tissue and bronchoalveolar lavage fluid was collected for analysis of surfactant protein mRNA and phosphatidylcholines (PCs).

RESULTS

FGR preterm lambs were 26% lighter than appropriate for gestational age (AGA) lambs and had baseline differences in lung mechanics and pulmonary blood flows. Surfactant therapy reduced ventilator and oxygen requirements and improved lung mechanics in both groups, although a more rapid improvement in compliance and tidal volume was observed in AGA lambs. Surfactant administration was associated with decreased mean pulmonary and carotid blood flow in FGR but not AGA lambs. No major differences in surfactant protein mRNA or PC levels were noted.

CONCLUSIONS

Surfactant therapy was associated with an altered pulmonary and cerebral hemodynamic response in preterm FGR lambs.

The clinical significance of an estimated fetal weight below the 10th percentile: a comparison of outcomes of <5th vs 5th-9th percentile

BACKGROUND

The association between small-for-gestational-age (birthweight <10th percentile for gestational age) and neonatal morbidity is well established. Yet, there is a paucity of data on the relationship between suspected small for gestational age (sonographic-estimated fetal weight <10th percentile) at 2 thresholds and subsequent neonatal morbidity.

OBJECTIVE

The objective of this study was to determine the relationship between sonographic-estimated fetal weight <5th percentile vs 5-9th percentile and neonatal morbidity.

STUDY DESIGN

This retrospective study involved 5 centers and included nonanomalous, singletons with sonographic-estimated fetal weight <10th percentile for gestational age who delivered from 2009-2012. Composite neonatal morbidity included respiratory distress syndrome, proven sepsis, intraventricular hemorrhage grade III or IV, necrotizing enterocolitis, thrombocytopenia, seizures, or death. Odd ratios were adjusted for center, maternal age, race, body mass index at first visit, smoking status, use of alcohol, use of drugs, and neonatal gender.

RESULTS

Of 834 women with suspected small-for-gestational-age fetuses, 513 (62%) had sonographic-estimated fetal weight <5th percentile, and 321 (38%) had sonographic-estimated fetal weight of 5-9th percentile for gestational age. At delivery, 81% of women with a suspected small-for-gestational-age fetus had a confirmed small-for-gestational-age fetus. In the group with a sonographic-estimated fetal weight <5th percentile, 59% of neonates had birthweight <5th percentile; in the group with a sonographic-estimated fetal weight 5-9th percentile, 41% had birthweight <5th percentile, and 36% had birthweight at 5-9th percentile. Neonatal intensive care unit admission differed significantly for those fetuses at <5th percentile (29%) compared with those fetuses at 5-9th percentile (15%; P<.001). The composite neonatal morbidity among the sonographic-estimated fetal weight <5th percentile group was higher than the sonographic-estimated fetal weight of 5-9th percentile group (31% vs 13%; adjusted odds ratio, 2.41; 95% confidence interval, 1.53-3.80). Similar findings were noted when the analysis was limited to sonographic-estimated fetal weight within 28 days of delivery (adjusted odds ratio, 2.22; 95% confidence interval, 1.34-3.67).

CONCLUSION

Eight of 10 suspected small-for-gestational-age fetuses had birthweight <10th percentile for gestational age; the prediction of actual birthweight was more accurate in the <5th percentile group. Neonates with sonographic-estimated fetal weight of <5th percentile were more likely to be admitted to the neonatal intensive care unit and have complications than were those neonates with sonographic-estimated fetal weight of 5-9th percentile.

Neonatal outcome of small for gestational age preterm infants

Small for gestational age (SGA) preterm neonates (birth weight < -2 SDS) are considered to have increased risk of bronchopulmonary dysplasia (BPD) compared to appropriate for GA (AGA) neonates. It is unclear if SGA infants have increased risk for respiratory distress syndrome (RDS) and mortality. We analyzed data from 515 neonates born <30 weeks GA, 98(19%) were SGA. SGA were compared to AGA by univariate analysis and logistic regression analysis (LRA). Significant variables at univariate analysis were IUGR (67 vs 7%, p = 0.000), chorioamnionitis (1 vs 13%, p = 0.017), pre-eclampsia (62 vs 18%, p = 0.000), surfactant retreatment (47 vs 25%, p = 0.000), BPD (32 vs 20%, p = 0.015), death (30 vs 12%, p = 0.000), SatO2/FiO2 on day 3 (376 vs 433, p = 0.013), and SatO2/FiO2 ratio on day 28 (400 vs 448, p = 0.000). LRA found the following associations: regarding mortality, a decreased Sat/FiO2 ratio on day 3 (OR 1.99, 95% CI 1.26-3.16, p = 0.003); regarding BPD, surfactant retreatment (3.70, 2.11-6.49, p = 0.000), being SGA (2.69, 1.36-5.36, p = 0.005), decreasing GA (1.05, 1.03-1.08, p = 0.000), decreasing SatO2/FiO2 ratio on day 3 (1.25, 1.11-1.40, p = 0.000); and regarding severe RDS, pre-eclampsia (2.68, 1.58-4.55, p = 0.000) and decreasing GA (1.06, 1.04-1.08, p = 0.000).

CONCLUSIONS

In our cohort of preterm infants, being SGA was significantly associated with BPD, but not with increased risk of mortality or RDS due to multiple pathophysiologic mechanisms. What is Known: • Small for gestational age preterm neonates are considered to have increased risk of bronchopulmonary dysplasia (BPD) compared to appropriate for GA neonates. • It is still unclear if SGA infants have increased risk for respiratory distress syndrome (RDS) and mortality. What is New: • In our cohort of 515 preterm infants (19% SGA), being SGA was significantly associated with BPD, but not with increased risk of mortality or RDS. • These results may be explained by the heterogeneity of mechanisms leading to SGA condition and by multiple mechanisms involving lung growth impairment and other factors.

Drug Closure of a Patent Ductus Arteriosus in An Extremely Low Birth Weight Premature Newborn. A Case Report

Introduction

Patent ductus arteriosus involves maintaining the permeability of the vascular ductus located between the pulmonary artery and the descending aorta, due to the failure of transition from foetal to adult type circulation. This malformation is characteristic to premature newborns with extremely low birth weight. The main pathophysiological factors identified in this pathology are immaturity of the smooth muscles, presence of vasodilator mediators and persistent hypoxaemia. Ductal-dependent cardiac malformations require drug therapy for keeping the permeability of the ductus arteriosus until the time of corrective surgery.

Case presentation

We present the case of an extremely low birth weight premature newborn, derived from twin pregnancy with suspected specific pathology, respectively feto-fetal transfusion syndrome, admitted to the Regional Centre of Neonatal Intensive Care Unit Tîrgu-Mureş.Premature newborn with gestational age 31-32 weeks, extremely low birth weight, derived from twin pregnancy, with adequate prenatal follow up, was born by caesarean section for severe intrauterine growth restriction secondary to feto-fetal transfusion syndrome suspicion. The newborn developed respiratory distress syndrome by surfactant deficiency, intraventricular-haemorrhage grade I/II, and severe retinopathy. The detection of a systolic murmur in the second week of life, the diastolic theft revealed by trans-fontanellar ultrasound as well as lowered diastolic blood pressure values raised the suspicion of a patent ductus arteriosus and therefore specific treatment with ibuprofen, a cyclooxygenase inhibitor, was initiated. Progressive alteration of the newborn's condition and the evidence of a coarctation of the aorta imposed the initiation of Prostaglandin E1 therapy and subsequent surgical correction.

Conclusions

Although beneficial, prophylactic or therapeutic closure of persistent ductus arteriosus may worsen the evolution of a newborn with a "silent" cardiac malformation and associated pathology.