Surfactant Replacement Therapy Research Articles

Risk factors for refractory respiratory distress syndrome among very-low-birth-weight infants

BackgroundThe objective was to evaluate refractory respiratory distress syndrome (RDS) risk factors among very-low-birth-weight infants (VLBWIs).MethodThe data of VLBWIs born between January 2013 and December 2020 registered in the Korean Neonatal Network (KNN) were analyzed. Infants who died within 5 postnatal days or who were not given surfactant were excluded. Infants were divided into a well-responding RDS group, which received surfactant replacement therapy (SRT) only once, and a refractory RDS group, which received SRT twice or more. The associations between perinatal characteristics and refractory RDS were investigated via multivariate logistic regression analysis.ResultsMultivariate logistic regression analysis revealed that low gestational age (adjusted odds ratio [aOR] = 1.26, 95% confidence interval (CI) [1.23, 1.26], male sex (aOR = 1.17, 95% CI [1.06, 1.29]), cesarean section (aOR = 1.59, 95% CI [1.38, 1.80]), maternal hypertensive disorder (aOR = 1.54, 95% CI[1.35, 1.75]), and low 5-minute Apgar scores (aOR = 1.24, 95% CI [1.12, 1.37]) were significantly associated with refractory RDS. Antenatal corticosteroid use (aOR = 0.81, 95% CI [0.73, 0.89]) and maternal chorioamnionitis (aOR = 0.79, 95% CI [0.71, 0.88]) were significantly inversely associated with refractory RDS. Compared with well-responding RDS, refractory RDS was significantly associated with increased major neonatal morbidity and mortality risk at 5 postnatal days.ConclusionMaternal hypertensive disorder is a significant risk factor for refractory RDS. Refractory RDS was associated with unfavorable neonatal outcomes.

Less invasive surfactant administration with specially designed semirigid catheter: Experience from a tertiary level neonatal unit of a lower middle-income country.

Clinical outcomes of 74 preterm neonates, who received surfactant replacement therapy (SRT), were collected retrospectively, to compare the following modes of administration: (1) less invasive surfactant administration (LISA) via a specially designed semirigid catheter (Surfcath), (2) INtubate-SURfactant-Extubate (INSURE) and (3) through endotracheal tube (ETT), in neonates requiring mechanical ventilation. The primary composite outcome of mortality or bronchopulmonary dysplasia (BPD) at 36 weeks' post-menstrual age was 41% in LISA, 38% in INSURE and 77% in ETT groups (p < 0.01), the difference being mainly due to the high incidence of mortality in the latter. LISA, via a specially designed semirigid catheter, was safe and feasible in preterm neonates.

Maternal cigarette smoking before or during pregnancy increases the risk of severe neonatal morbidity after delivery: a nationwide population-based retrospective cohort study

BackgroundThe association of maternal cigarette smoking during pregnancy with severe neonatal morbidity (SNM) is still inconclusive. We aimed to examine the associations of the timing and the intensity of maternal...

Comparative biophysical study of clinical surfactants using constrained drop surfactometry.

Surfactant replacement therapy is crucial in managing neonatal respiratory distress syndrome (RDS). Currently licensed clinical surfactants in the United States and Europe, including Survanta, Infasurf, Curosurf, and Alveofact, are all derived from bovine or porcine sources. We conducted a comprehensive examination of the biophysical properties of these four clinical surfactant preparations under physiologically relevant conditions, using constrained drop surfactometry (CDS). The assessed biophysical properties included the adsorption rate, quasi-static and dynamic surface activity, resistance to surfactant inhibition by meconium, and the morphology of the adsorbed surfactant films. This comparative study unveiled distinct in vitro biophysical properties of these clinical surfactants and revealed correlations between their chemical composition, lateral film structure, and biophysical functionality. Notably, at 1 mg/mL, Survanta exhibited a significantly lower adsorption rate compared with the other preparations at the same surfactant concentration. At 10 mg/mL, Infasurf, Curosurf, and Survanta all demonstrated excellent dynamic surface activity, whereas Alveofact exhibited the poorest quasi-static and dynamic surface activity. The suboptimal surface activity of Alveofact is found to be correlated with its unique monolayer-predominant morphology, in contrast to other surfactants forming multilayers. Curosurf, in particular, showcased superior resistance to biophysical inhibition by meconium compared with other preparations. Understanding the diverse biophysical behaviors of clinical surfactants provides crucial insights for precision and personalized design in treating RDS and other respiratory conditions. The findings from this study contribute valuable perspectives for the development of more efficacious and fully synthetic surfactant preparations.NEW & NOTEWORTHY A thorough investigation into the biophysical properties of four animal-derived clinical surfactant preparations was conducted through constrained drop surfactometry under physiologically relevant conditions. This comparative study unveiled unique in vitro biophysical characteristics among these clinical surfactants, establishing correlations between their chemical composition, lateral film structure, and biophysical functionality. The acquired knowledge offers essential insights for the precise and personalized design of clinical surfactant for the treatment of respiratory distress syndrome and other respiratory conditions.

Impact of Surfactant Therapy on Preterm Neonates: A Meta-Analysis Evaluating Respiratory and Hemodynamic Outcomes

Introduction: Surfactant deficiency is a major contributor to neonatal respiratory distress syndrome (RDS) in preterm infants. Surfactant replacement therapy has become a cornerstone in managing RDS, but its impact on broader respiratory and hemodynamic outcomes remains an area of active investigation. This meta-analysis aimed to comprehensively evaluate the effects of surfactant therapy on preterm neonates, encompassing both respiratory and hemodynamic parameters. Methods: A systematic search of electronic databases (PubMed, Embase, Cochrane Library) was conducted to identify randomized controlled trials (RCTs) and observational studies evaluating surfactant therapy in preterm neonates. Studies reporting on respiratory outcomes (need for mechanical ventilation, duration of ventilation, oxygen requirement) and hemodynamic outcomes (patent ductus arteriosus (PDA) incidence, blood pressure, cerebral blood flow) were included. Data extraction and quality assessment were performed independently by two reviewers. Meta-analyses were conducted using random-effects models. Results: A total of 35 studies (22 RCTs, 13 observational studies) involving 4,875 preterm neonates were included. Surfactant therapy was associated with a significant reduction in the need for mechanical ventilation (RR 0.72, 95% CI 0.65-0.80, p&lt;0.001), duration of mechanical ventilation (MD -1.8 days, 95% CI -2.5 to -1.1, p&lt;0.001), and oxygen requirement (MD -5%, 95% CI -7 to -3, p&lt;0.001). A trend towards reduced incidence of PDA was observed (RR 0.85, 95% CI 0.71-1.02, p=0.08). Surfactant therapy also led to improvements in blood pressure parameters and cerebral blood flow. Conclusion: Surfactant therapy in preterm neonates confers significant benefits in respiratory outcomes, including reduced need for and duration of mechanical ventilation, and decreased oxygen requirement. A potential beneficial effect on PDA incidence warrants further investigation. These findings underscore the critical role of surfactant therapy in improving the respiratory and hemodynamic status of preterm neonates.

Recombinant fragment of human surfactant protein D to prevent neonatal chronic lung disease (RESPONSE): a protocol for a phase I safety trial in a tertiary neonatal unit

IntroductionChronic respiratory morbidity from bronchopulmonary dysplasia (BPD) remains the most common complication of preterm birth and has consequences for later respiratory, cardiovascular and neurodevelopmental outcomes. The early phases of respiratory...

Hemodynamically significant patent ductus arteriosus profile in preterm neonates (26-34 weeks' gestation) undergoing surfactant replacement therapy in India: a prospective observational study.

Surfactant administration significantly improves respiratory outcomes in preterm infants with respiratory distress syndrome (RDS). However, surfactant administration may lead to hemodynamic alterations, particularly in the heart, affecting the patent ductus arteriosus (PDA), the consequences of which are not fully understood. This prospective observational study took place in an Indian neonatal care unit from July 2019 to November 2020, enrolling preterm neonates (26-34 weeks' gestation) with RDS needing non-invasive positive pressure ventilation. They were divided into two groups: those who received surfactant while on respiratory support and those who did not. All newborns in the study had an initial echocardiogram within 24 h to detect PDA flow. Subsequent echocardiograms were conducted between 48 and 72 h or earlier based on symptoms. Of 220 infants requiring respiratory support, 84 were enrolled, with 42 in each group. While demographic variables were similar, the surfactant group had a lower median gestational age (29.0 vs. 31.0 weeks). In the surfactant group, a significantly higher percentage of neonates had hemodynamically significant PDA (hsPDA) compared to the non-surfactant group (54.76% vs. 26.19%, P-value = .008). Multiple logistic regression found no significant association between gestation, birth weight, or shock and hsPDA occurrence. Pulmonary hemorrhage occurred more often in the surfactant group. Bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) > grade 2, and necrotizing enterocolitis (NEC) ≥ grade 2 did not differ significantly between the groups. Surfactant therapy via the less invasive surfactant administration technique was associated with a higher incidence of hsPDA. While surfactant is crucial for neonatal respiratory care, its potential hemodynamic effects, including hsPDA, should be considered.

Lung ultrasound for prediction of surfactant requirement in Indian preterm neonates: a diagnostic accuracy study.

Surfactant replacement for respiratory distress syndrome (RDS) is currently guided by oxygen (FiO2) requirement in preterm neonates. Lung ultrasound (LUS) has emerged as an important predictive tool; however, there is a paucity of evidence from developing countries.The objective of this study was to determine the diagnostic accuracy of the LUS score in comparison to standard criteria based on FiO2 requirement for prediction of surfactant requirement.In this prospective study, preterm neonates of < 34 weeks' gestation with RDS were included within 2 h of life. Surfactant was administered if the FiO2 requirement exceeded 30%. Baseline characteristics, respiratory parameters, and LUS clips were recorded soon after birth and compared between the surfactant and non-surfactant groups. LUS scoring was later performed by masked assessors which was not used in the management of neonates.Among 82 neonates (mean gestation 30.6 weeks and weight 1375 g) included in the study, 33 (40.2%) received surfactant. The surfactant group had a higher Silverman score, required higher FiO2 and mean airway pressure, and needed invasive ventilation more frequently. The mean (± SD) LUS score was significantly higher in the surfactant (9.4 ± 3.2) compared to the non-surfactant group (5.1 ± 2.1). The diagnostic accuracy of LUS scoring was determined by ROC curve analysis (AUC (95% CI): 0.83 (0.74-0.92), p < 0.01). A cutoff score of ≥ 8 for LUS was considered optimal for the prediction of surfactant requirement (sensitivity and specificity (95% CI) of 70% (51-84) and 80% (66-90), respectively). Conclusion:Lung ultrasound is a valid diagnostic tool for the prediction of surfactant requirements in resource-limited settings. What is Known: • Lung ultrasound has a good diagnostic accuracy in predicting the need for surfactant administration in preterm neonates in developed countries, but its role in developing countries is unclear. What is New: • Lung ultrasound proved to be a valid diagnostic tool in predicting surfactant replacement therapy in resource-limited settings. • The diagnostic performance of lung ultrasound was better in neonates on non-invasive ventilation, compared to invasive ventilation.

Surfactant Therapy in Respiratory Distress Syndrome

Respiratory distress syndrome (RDS) is the leading cause of neonatal respiratory morbidity and mortality. Advancements in neonatal care, along with extended insurance coverage, have resulted in increased utilization of surfactant replacement therapy (SRT) for RDS. This has contributed to a decrease in neonatal mortality. The primary mode of respiratory support in infants with RDS has dramatically changed over the last decades, transitioning from invasive to noninvasive support. Therefore, less invasive surfactant therapy has emerged as a widely adopted approach for SRT, establishing itself as a standard method in preterm infants’ care. This review addresses pulmonary surfactant, from its discovery to application in newborns with RDS. It also reviews the history of guidelines of SRT and health insurance issues. Future studies should evaluate various emerging noninvasive respiratory support modalities along with SRT for the respiratory management of neonates, given the lack of sufficient evidence regarding these approaches.

The Synthetic Surfactant CHF5633 Restores Lung Function and Lung Architecture in Severe Acute Respiratory Distress Syndrome in Adult Rabbits

PurposeAcute respiratory distress syndrome (ARDS) is a major cause of hypoxemic respiratory failure in adults. In ARDS extensive inflammation and leakage of fluid into the alveoli lead to dysregulation of pulmonary surfactant metabolism and function. Altered surfactant synthesis, secretion, and breakdown contribute to the clinical features of decreased lung compliance and alveolar collapse. Lung function in ARDS could potentially be restored with surfactant replacement therapy, and synthetic surfactants with modified peptide analogues may better withstand inactivation in ARDS alveoli than natural surfactants.MethodsThis study aimed to investigate the activity in vitro and the bolus effect (200 mg phospholipids/kg) of synthetic surfactant CHF5633 with analogues of SP‐B and SP‐C, or natural surfactant Poractant alfa (Curosurf®, both preparations Chiesi Farmaceutici S.p.A.) in a severe ARDS model (the ratio of partial pressure arterial oxygen and fraction of inspired oxygen, P/F ratio ≤ 13.3 kPa) induced by hydrochloric acid instillation followed by injurious ventilation in adult New Zealand rabbits. The animals were ventilated for 4 h after surfactant treatment and the respiratory parameters, histological appearance of lung parenchyma and levels of inflammation, oxidative stress, surfactant dysfunction, and endothelial damage were evaluated.ResultsBoth surfactant preparations yielded comparable improvements in lung function parameters, reductions in lung injury score, pro-inflammatory cytokines levels, and lung edema formation compared to untreated controls.ConclusionsThis study indicates that surfactant replacement therapy with CHF5633 improves lung function and lung architecture, and attenuates inflammation in severe ARDS in adult rabbits similarly to Poractant alfa. Clinical trials have so far not yielded conclusive results, but exogenous surfactant may be a valid supportive treatment for patients with ARDS given its anti-inflammatory and lung-protective effects.

Gastric Fluid Metabolomics Predicting the Need for Surfactant Replacement Therapy in Very Preterm Infants Results of a Case-Control Study.

Respiratory distress syndrome (RDS) is a major morbidity of prematurity. In this case-control study, we prospectively evaluated whether untargeted metabolomic analysis (gas chromatography-mass spectrometry) of the gastric fluid could predict the need for surfactant in very preterm neonates. 43 infants with RDS necessitating surfactant (cases) were compared with 30 infants who were not treated with surfactant (controls). Perinatal-neonatal characteristics were recorded. Significant differences in gastric fluid metabolites (L-proline, L-glycine, L-threonine, acetyl-L-serine) were observed between groups, but none could solely predict surfactant administration with high accuracy. Univariate analysis revealed significant predictors of surfactant administration involving gastric fluid metabolites (L-glycine, acetyl-L-serine) and clinical parameters (gestational age, Apgar scores, intubation in the delivery room). Multivariable models were constructed for significant clinical variables as well as for the combination of clinical variables and gastric fluid metabolites. The AUC value of the first model was 0.69 (95% CI 0.57-0.81) and of the second, 0.76 (95% CI 0.64-0.86), in which acetyl-L-serine and intubation in the delivery room were found to be significant predictors of surfactant therapy. This investigation adds to the current knowledge of biomarkers in preterm neonates with RDS, but further research is required to assess the predictive value of gastric fluid metabolomics in this field.

Use of surfactant beyond respiratory distress syndrome, what is the evidence?

Surfactant replacement therapy is currently approved by the United States Food and Drug Administration (FDA) for premature infants with respiratory distress syndrome (RDS) caused by surfactant deficiency due to immaturity. There is strong evidence that surfactant decreases mortality and air leak syndromes in premature infants with RDS. However, surfactant is also used "off-label" for respiratory failure beyond classic RDS. This review discusses current evidence for the use of off-label surfactant therapy for (1) term infants with lung disease such as meconium aspiration syndrome (MAS), pneumonia/sepsis, and congenital diaphragmatic hernia (2) premature infants after 72 h for acute respiratory failure, and (3) the use of surfactant lavage. At last, we briefly describe the use of surfactants for drug delivery and the current evidence on evaluating infants for surfactant deficiency.

Design and fabrication of a three-dimensional asymmetric neonate lung model to study surfactant transport in airways

Neonatal respiratory distress syndrome is a potentially life-threatening condition that is often treated with the delivery of exogenous surfactants through a process called surfactant replacement therapy. This therapy includes the administration of the liquid surfactant through an endotracheal tube and mechanical ventilation. Due to the difficulty of imaging neonate lungs during this therapy, the success of surfactant delivery is often determined by observational techniques and evaluation of blood oxygen levels. The limitation of imaging creates challenges in evaluating the distribution of surfactant in airways. To address this limitation, we designed a computational, eight-generation, asymmetric neonate lung model using morphometric data to mimic the geometric structure of the human airway tree and fabricated it using an additive manufacturing technique. We used our model to study two-aliquot delivery of a clinically rated liquid surfactant under two different orientations to evaluate its distribution in airways. Our study offers a complex lung airway tree design that mimics the native geometry of the human airway tree to enable studies of therapeutics transport in airways.

Outcome of Surfactant Replacement Therapy in Premature Neonates in ICU of Ibn Sina Teaching Hospital of Sirte, Libya in Period Between May – 2019 to May – 2022

Introduction :Respiratory distress syndrome (RDS) is an acute lung disease of preterm babies caused by surfactant insufficiency . Decreased surfactant results in insufficient surface tension in the alveolus during expiration leading to alveolar collapse , atelectasis , impaired gas exchange , severe hypoxia and acidosis , leading to respiratory failure . Surfactant replacement therapy (SRT) is now accepted as the standard treatment of preterm babies with RDS . Objective : The objective of this study was to analyze the incidence and outcome of surfactant replacement therapy in preterm babies with RDS . Methodology : This is Quantitative retrospective study , conducted in Neonatal Intensive Care Units (NICU) of Ibn Sina Teaching Hospital , Sirte , Libya . Study duration was of three years period ( May – 2019 to May – 2022 ) . Preterm babies from 24 wks to 36 wks of gestation with RDS received SRT were included in this study . The surfactant was administrated intra- tracheally according to standard procedures . Results :In this study of 41 preterm babies with RDS received SRT , 30 ( 73.2% ) were male and 11 ( 26.8% ) were female . The mean gestational age was 33.12 weeks . Among 41 preterm babies with RDS receiving SRT , 21 ( 51.2% ) discharged from the hospital and 20 ( 48.8% ) expired . Maximum survival was seen in the gestational age of ≥32 wks and birth weight ≥ 1500 gms . Conclusion : The use of SRT has improved the survival outcome and decreased the associated morbidities in babies with RDS . The maximum impact of survival was seen in the oreterm babies of ≥ 32 weeks with birth weight of ≥ 1500 grams .

Diagnostic utility of lung ultrasound in predicting the need for surfactant therapy in preterm neonates with respiratory distress.

Lung ultrasound is an accurate and early predictor for surfactant replacement therapy in respiratory distress syndrome (RDS) as compared to clinical parameters and chest x-ray. However, lung pathologies for respiratory distress at birth have overlapping symptomatology and low middle-income countries have a higher incidence of congenital pneumonia, in addition to RDS, making the immediate diagnosis difficult. Thus, there is a need for assessing a cutoff for lung ultrasound scores in the given setting. The primary objective was to determine the diagnostic accuracy of the lung ultrasound score (LUS) in predicting the need for surfactant therapy in preterm neonates with respiratory distress. Secondary objectives were to correlate LUS with corresponding oxygen saturation to the fraction of inspired oxygen ratio (SpO2/FiO2), arterial/Alveolar oxygen pressure ratio (a/A), and chest x-ray (CXR) findings. A prospective observational study was carried out at a tertiary-level neonatal intensive care unit in India in 2022 enrolling 100 neonates <34 weeks gestational age with respiratory distress at birth. After initial stabilization of the neonate, LUS was performed and baseline parameters were noted. Surfactant was administered as per the 2019 European Consensus guidelines and LUS was repeated after 6 h of therapy. The mean gestation of enrolled neonates was 31.06 ± 2.12 weeks and the mean birthweight was 1,412 ± 391 g. Approximately 58% were diagnosed with RDS and 30% had congenital pneumonia. Surfactant was administered to 40% of neonates. The cutoff LUS for surfactant therapy was 7 [area under the curve (AUC) 0.977; 95% CI, 0.947-1; P < 0.001; with sensitivity 92.5%, specificity 96.67%, PPV 94.87%, and NPV 95.08%] and the cutoff LUS for the second dose of surfactant was 10 (AUC 0.964; 95% CI, 0.913-1; P < 0.001). The score decreased by 3.24 (2.44-4.05) after 6 h of the first dose and correlated significantly with SpO2/FiO2 ratio (-0.750), a/A ratio (-0.650), and CXR findings (0.801). The study predicted an optimal LUS cutoff of 7 and 10 for the need for the first dose of surfactant and re-treatment, respectively, in neonates <34 weeks gestational age with respiratory distress.

Comparison of the efficacy of two natural surfactants (BERAKSURF and BLES) in the treatment of respiratory distress syndrome among preterm neonates

BackgroundThe benefit of surfactant replacement therapy for respiratory distress syndrome (RDS) has been demonstrated. However, some surfactants are expensive and usually inaccessible. Consequently, the Iranian Survanta was produced, but its effect on complications and mortality of RDS is unknown. This study aimed to compare the therapeutic outcomes of Iranian surfactant (beraksurf) and BLES (bovine lipid extract surfactant) on RDS treatment among preterm neonates.MethodsThis triple blinded randomized controlled trial study was performed on 128 eligible neonates diagnosed with RDS in Afzalipour hospital in Kerman, Iran. Diagnosis of RDS, gestational age of 28–34 weeks and weight ≥ 1 kg were considered as inclusion criteria. Congenital anomalies such as congenital cyanotic heart diseases, digestive system anomalies and chromosome abnormalities were the exclusion criteria Neonates were randomly assigned into two equal groups: (1) those treated with BLES (n = 64) and (2) those treated with beraksurf (n = 64). Complications including patent ductus arteriosus (PDA), sepsis, intraventricular hemorrhage (IVH), pneumothorax, pulmonary hemorrhage, mortality, and also, the number of days required for invasive mechanical ventilation (using ventilator) and non-invasive continuous positive airway pressure (CPAP) were evaluated for all neonates. The risk ratio (RR) was calculated at 95% of confidence intervals (CI).ResultsCompared with BLES group, the RR estimate among neonates in beraksurf group was 0.89 (0.66–1.20) for PDA, 0.71 (0.23–2.13) for IVH, 0.44 (0.14–1.36) for sepsis, 0.35 (0.13–0.93) for pneumothorax, 0.33 (0.12–0.86) for pulmonary hemorrhage, and 0.55 (0.28–1.05) for mortality.ConclusionsDespite advances in the use of exogenous surfactants for the treatment of neonatal respiratory distress syndrome; There are still some controversial topics in this field. The results obtained in the present study showed that the two types of surfactant (BERAKSURF and BLES) have similar efficacy for the treatment and short-term outcomes in preterm infants with respiratory distress syndrome. Therefore, due to the cost-effectiveness of BRAKSURF compared to BLES, We recommend choosing BERAKSURF in terms of treatment.

Inhaled pulmonary surfactant biomimetic liposomes for reversing idiopathic pulmonary fibrosis through synergistic therapeutic strategy

Idiopathic pulmonary fibrosis (IPF) stands as a highly heterogeneous and deadly lung disease, yet the available treatment options remain limited. Combining myofibroblast inhibition with ROS modulation in damaged AECs offers a comprehensive strategy to halt IPF progression, but delivering drugs separately to these cell types is challenging. Inspired by the successful application of pulmonary surfactant (PS) replacement therapy in lung disease treatment, we have developed PS nano-biomimetic liposomes (PSBs) to utilize its natural transport pathway for targeting AECs while reducing lung tissue clearance. In this collaborative pulmonary drug delivery system, PSBs composed of DPPC/POPG/DPPG/CHO (20:9:5:4) were formulated for inhalation. These PSBs loaded with ROS-scavenger astaxanthin (AST) and anti-fibrosis drug pirfenidone (PFD) were aerosolized for precise quantification and mimicking patient inhalation. Through aerosol inhalation, the lipid membrane of PSBs gradually fused with natural PS, enabling AST delivery to AECs by hitchhiking with PS circulation. Simultaneously, PFD was released within the PS barrier, effectively penetrating lung tissue to exert therapeutic effects. In vivo results have shown that PSBs offer numerous therapeutic advantages in mice with IPF, particularly in terms of lung function recovery. This approach addresses the challenges of drug delivery to specific lung cells and offers potential benefits for IPF patients.

Lung UltrasouNd Guided surfactant therapy in preterm infants: an international multicenter randomized control trial (LUNG study)

BackgroundThe management of respiratory distress syndrome (RDS) in premature newborns is based on different types of non-invasive respiratory support and on surfactant replacement therapy (SRT) to avoid mechanical ventilation as it may eventually result in lung damage. European guidelines currently recommend SRT only when the fraction of inspired oxygen (FiO2) exceeds 0.30. The literature describes that early SRT decreases the risk of bronchopulmonary dysplasia (BPD) and mortality. Lung ultrasound score (LUS) in preterm infants affected by RDS has proven to be able to predict the need for SRT and different single-center studies have shown that LUS may increase the proportion of infants that received early SRT.Therefore, the aim of this study is to determine if the use of LUS as a decision tool for SRT in preterm infants affected by RDS allows for the reduction of the incidence of BPD or death in the study group.Methods/designIn this study, 668 spontaneously-breathing preterm infants, born at 25+0 to 29+6 weeks’ gestation, in nasal continuous positive airway pressure (nCPAP) will be randomized to receive SRT only when the FiO2 cut-off exceeds 0.3 (control group) or if the LUS score is higher than 8 or the FiO2 requirements exceed 0.3 (study group) (334 infants per arm). The primary outcome will be the difference in proportion of infants with BPD or death in the study group managed compared to the control group.DiscussionBased on previous published studies, it seems that LUS may decrease the time to administer surfactant therapy. It is known that early surfactant administration decreases BPD and mortality. Therefore, there is rationale for hypothesizing a reduction in BPD or death in the group of patients in which the decision to administer exogenous surfactant is based on lung ultrasound scores.Trial registrationClinicalTrials.gov identifier NCT05198375. Registered on 20 January 2022.

Excipient-free lyophilization of block copolymer micelles for potential lung surfactant therapy applications

Polymer lung surfactant (PLS) is a polyethylene glycol (PEG)-brushed block copolymer micelle designed for pulmonary surfactant replacement therapy. Saccharides (e.g., sucrose and (2-hydroxypropyl)-β-cyclodextrin) and water-soluble polymers (e.g., PEG), common excipients for lyophilization, were found to severely impair the surface activity of lyophilized PLS. To investigate the feasibility of excipient-free lyophilization of PLS, we studied the effects of both PLS material parameters and lyophilization operating parameters on the redispersibility and surface availability of reconstituted PLS, all without relying on excipients. We found that the redispersibility was improved by three factors; a faster cooling rate during the freezing stage reduced freezing stress; a higher PEG grafting density enhanced dissipating effects; and the absence of hydrophobic endgroups in the PEG block further prevented micelle aggregation. Consequently, the surface availability of PLS increased, enabling the micelle monolayer at the air/water interface to achieve a surface tension below 10 mN/m, which is a key pharmaceutical function of PLS. Moreover, the lyophilized micelles in powder form could be easily dispersed on water surfaces without the need for reconstitution, which opens up the possibility of inhalation delivery, a more patient-friendly administration method compared to instillation. The successful excipient-free lyophilization unlocks the potential of PLS for addressing acute respiratory distress syndrome (ARDS) and other pulmonary dysfunctions.

Comparison of mortality and short-term outcomes between classic, intubation-surfactant-extubation, and less invasive surfactant administration methods of surfactant replacement therapy.

Intubation-Surfactant-Extubation (InSurE) and less invasive surfactant administration (LISA) are alternative surfactant replacement therapy methods for reducing the complications associated with invasive mechanical ventilation. This study aimed to compare the Classic, InSurE, and LISA methods in Very-Low-Birth-Weight infants (VLBWIs) in South Korea. The Korean Neonatal Network (KNN) enrolled VLBWIs born between January 1, 2019 and December 31, 2020. They were analyzed retrospectively to compare the duration of respiratory support, length of hospitalization, mortality, and short-term outcomes of the three groups. The duration of invasive ventilator support was shorter in the following order: InSurE (3.99 ± 11.93 days), LISA (8.78 ± 29.32 days), and the Classic group (22.36 ± 29.94 days) (p = 0.014, p < 0.01) and InSurE had the shortest hospitalization (64.91 ± 24.07 days, p < 0.05) although the results couldn't adjust for confounding factor because of irregular distribution. InSurE had the lower risk of intraventricular hemorrhage (IVH) grade II-IV [odds ratio (OR) 0.524 [95% confidence interval (CI): 0.287-0.956], p = 0.035] than in the Classic group. Mortality was lower in the InSurE [OR 0.377 (95% CI: 0.146-0.978), p = 0.045] and LISA [OR 0.296 (95% CI: 0.102-0.862), p = 0.026] groups than in the Classic group. There was a reduced risk of moderate to severe bronchopulmonary dysplasia (BPD) [OR 0.691 (95% CI: 0.479-0.998, p = 0.049), OR 0.544 (95% CI: 0.355-0.831, p = 0.005), respectively], pulmonary hypertension [OR 0.350 (95% CI: 0.150-0.817, p = 0.015), OR 0.276 (95% CI: 0.107-0.713, p = 0.008), respectively], periventricular leukomalacia (PVL) [OR 0.382 (95% CI: 0.187-0.780, p = 0.008), OR 0.246 (95% CI: 0.096-0.627, p = 0.003), respectively], and patent ductus arteriosus (PDA) with treatment [OR 0.628 (95% CI: 0.454-0.868, p = 0.005), OR 0.467 (95% CI: 0.313-0.696, p < 0.001) respectively] in the InSurE and LISA groups compared to the Classic group. InSurE showed the lowest duration of invasive ventilator support, length of hospitalization. InSurE and LISA exhibited reduced mortality and decreased risks of moderate to severe BPD, pulmonary hypertension, PVL, and PDA with treatment compared to the Classic group.