Surfactant administration without intubation in preterm infants with respiratory distress syndrome – our experiences

Minimal invasive surfactant therapy in preterm infants with respiratory distress syndrome: a single-center experience

BACKGROUND

Minimal invasive surfactant therapy (MIST) includes the tracheal instillation of surfactant via a thin catheter for the treatment of preterm infants with respiratory distress syndrome (RDS). We aimed to evaluate the impact of MIST compared to intubation, surfactant, extubation (INSURE) technique on respiratory outcomes.

METHODS

A prospectively recruited cohort of preterm infants ≤32 weeks with RDS was compared against a historical cohort of infants treated with INSURE. The primary outcome was the need for mechanical ventilation within 72 hours of age and secondary outcomes the overall need and duration of mechanical ventilation, the development of bronchopulmonary dysplasia, common morbidities, and survival.

RESULTS

Thirty-six infants treated with MIST of 29.1±2.2 weeks' gestation and 1219±238 g birthweight compared against 37 infants of 28.8±2.3 weeks' gestation and 1195±336 g birthweight treated with INSURE. A lower proportion of infants treated with MIST required mechanical ventilation within 72 hours of age compared to those treated with INSURE (11% compared 32%, P=0.042). However, no significant differences were noted regarding the overall intubation incidence, bronchopulmonary dysplasia, other morbidities, or survival.

CONCLUSIONS

In spontaneously breathing infants ≤32 weeks with RDS, the MIST technique was associated with a lower need for intubation within 72 hours of age, but otherwise with no significant differences regarding BPD or other neonatal morbidities.

A clinical study evaluating the combination of LISA and SNIPPV for the treatment of respiratory distress syndrome in preterm infants

To compare the therapeutic effect of less invasive surfactant administration (LISA) followed by synchronized nasal intermittent positive pressure ventilation (SNIPPV) and traditional intubate-Surfactant-Extubate (InSurE) strategy for the treatment of neonatal respiratory distress syndrome (NRDS). A single-center, non-randomized and single- blinded study Tertiary neonatal intensive care unit 89 infants enrolled were preterm with gestational age < 366/7 weeks and clinically diagnosed with neonatal RDS (NRDS) Interventions: 32 infants were assigned to the LISA + SNIPPV group and 57 infants to the InSurE + nCPAP group. No statistically significant differences were noted in the baseline characteristics of the enrolled infants. A lower proportion of infants developed BPD in the LISA + SNIPPV group compared to the InSurE + CPAP group [10 (31.25%) vs. 21 (36.84%), P > 0.05]; however, there was no statistically significant difference. The number needed to treat (NNT) with LISA + SNIPPV to prevent BPD development is 18. The mortality rate was not significant between our study arms [1 (3.13%) vs 2 (3.51%), P > 0.05]. There were no statistically significant differences in the durations (days) of MV [(12.18 ± 13.89) vs. (11.35 ± 11.61), P > 0.05], oxygen therapy [(35.03 ± 19.13) vs. (39.75 ± 17.91), P > 0.05] and re-intubation rates [(0.19 ± 0.40) vs. (0.21 ± 0.45), P > 0.05] between the two study groups. In terms of complications, the incidence of patent ductus arteriosus (PDA) [24 (75.00%) vs. 27 (47.37%), P < 0.05] was higher and a lower rate of disturbed liver function [1 (3.23%) vs. 19 (33.33%), P < 0.05] were observed in the LISA + SNIPPV group. Acid-base imbalances were reportedly significantly higher in the InSurE group (P < 0.05). No significant differences in other complications were noted. In the interventional group, FiO2 requirements were significantly lower up until the 3rd week of treatment [FiO2 at day 0, (30.75 ± 4.78) vs. (34.66 ± 9.83), P < 0.05; FiO2 at day 21, (25.32 ± 3.74) vs. (29.11 ± 8.17), P < 0.05], as was RSS on days 2 [(0.77 ± 0.38) vs. (1.94 ± 0.75), P < 0.05] and 3 [(0.66 ± 0.33) vs. (1.89 ± 0.82), P < 0.05] after treatment. Additionally, infants in the standard group had a significantly prolonged hospital stay (days) [(45.97 ± 16.93) vs. (54.40 ± 16.26), P < 0.05]. The combination of LISA and SNIPPV for NRDS can potentially lower the rate of BPD, FiO2 demand and shorten the length of hospitalization.

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

Background

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.

Methods

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.

Results

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.

Conclusion

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.

Surfactant delivery via thin catheters: Methods, limitations, and outcomes

Various less invasive surfactant administration strategies like surfactant replacement therapy via thin catheters, laryngeal mask airway, pharyngeal instillation, and nebulized surfactant are increasingly being practiced to avoid the harmful effects of endotracheal intubation and ventilation. Numerous studies have been done to study surfactant replacement via thin catheters whereas little data is available for other methods. However, there are variations in premedication policies, type of respiratory support used in these studies. Surfactant delivery using thin catheters has been reported to be associated with decrease in the need for mechanical ventilation (MV), duration of MV, bronchopulmonary dysplasia and neonatal mortality. With the current evidence, among all the available surfactant delivery methods, the one using thin catheters appears to be the most feasible and beneficial to improve clinical neonatal outcomes.

Comparative efficacy of methods for surfactant administration: a network meta-analysis

OBJECTIVES

To compare surfactant administration via thin catheters, laryngeal mask, nebulisation, pharyngeal instillation, intubation and surfactant administration followed by immediate extubation (InSurE) and no surfactant administration.

DESIGN

Network meta-analysis.

SETTING

Medline, Scopus, CENTRAL, Web of Science, Google-scholar and Clinicaltrials.gov databases were systematically searched from inception to 15 February 2020.

PATIENTS

Preterm neonates with respiratory distress syndrome.

INTERVENTIONS

Less invasive surfactant administration.

MAIN OUTCOME MEASURES

The primary outcomes were mortality, mechanical ventilation and bronchopulmonary dysplasia.

RESULTS

Overall, 16 randomised controlled trials (RCTs) and 20 observational studies were included (N=13 234). For the InSurE group, the median risk of mortality, mechanical ventilation and bronchopulmonary dysplasia were 7.8%, 42.1% and 10%, respectively. Compared with InSurE, administration via thin catheter was associated with significantly lower rates of mortality (OR: 0.64, 95% CI: 0.54 to 0.76), mechanical ventilation (OR: 0.43, 95% CI: 0.29 to 0.63), bronchopulmonary dysplasia (OR: 0.57, 95% CI: 0.44 to 0.73), periventricular leukomalacia (OR: 0.66, 95% CI: 0.53 to 0.82) with moderate quality of evidence and necrotising enterocolitis (OR: 0.67, 95% CI: 0.41 to 0.9, low quality of evidence). No significant differences were observed by comparing InSurE with administration via laryngeal mask, nebulisation or pharyngeal instillation. In RCTs, thin catheter administration lowered the rates of mechanical ventilation (OR: 0.39, 95% CI: 0.26 to 0.60) but not the incidence of the remaining outcomes.

CONCLUSION

Among preterm infants, surfactant administration via thin catheters was associated with lower likelihood of mortality, need for mechanical ventilation and bronchopulmonary dysplasia compared with InSurE. Further research is needed to reach firm conclusions about the efficacy of alternative minimally invasive techniques of surfactant administration.

Dexamethasone may inhibit placental growth by blocking glucocorticoid receptors via phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin and reactive oxygen species/AMP-activated protein kinase signalling pathways in human placental JEG-3 cells

This study explored the molecular mechanism underlying the effects of dexamethasone (DEX, 1µM) on glucose transporters (GLUT) in JEG-3 human placental choriocarcinoma cells. JEG-3 cells were treated with DEX, an expression plasmid encoding human glucocorticoid receptor α (GRα), pcDNA3.1-GRα, GRα short interference (si) RNA, LY294002, xanthine oxidase (XO)/hypoxanthine (HX), rapamycin, insulin-like growth factor (IGF) 1, N-acetylcysteine (NAC) or phosphatidic acid (PA), and cell proliferation, apoptosis, mitochondrial membrane potential (MMP), human chorionic gonadotrophin (hCG) content, human placental lactogen (hPL) content, glucose uptake, reactive oxygen species levels and signalling pathway modulation were evaluated. Treatment of JEG-3 cells with DEX (1µM), GRα siRNA, LY294002 (50µM), XO/HX (7.2µM/36nM) or rapamycin (80nM) inhibited cell proliferation, induced apoptosis, significantly decreased MMP and hCG and hPL content and increased ROS levels. In addition, glucose uptake was decreased through downregulation of the mRNA and protein expression of GRα, GLUT1 and GLUT3. Treatment of JEG-3 cells with GRα siRNA, LY294002, XO/HX or rapamycin inhibited phosphorylation of phosphatidylinositol 3-kinase (PI3K), Akt, glycogen synthase kinase 3 and mammalian target of rapamycin (mTOR) and induced the phosphorylation of AMP-activated protein kinase (AMPK) and tuberous sclerosis complex 2. The effects of GRα overexpression and IGF1 (100nM), NAC (5nM) or PA (100µM) treatment on JEG-3 cells contrasted with those of DEX treatment. DEX blocked glucose uptake by downregulating GRα expression, which reduced GLUT1 and GLUT3 mRNA and protein expression, which, in turn, may have inhibited the PI3K/AKT/mTOR pathway and activated the ROS/AMPK pathway.

A comparison of LISA versus InSurE: A single center experience

BACKGROUND

Less invasive surfactant replacement therapy (SRT) methods have been linked to better respiratory outcomes. The primary aim of this study was to determine if Less Invasive Surfactant Administration (LISA) altered the rate of bronchopulmonary dysplasia (BPD) in preterm infants. Secondary objectives were to determine if LISA compared to Intubation Surfactant Extubation (InSurE) resulted in different respiratory outcomes and hospital course.

METHODS

In this retrospective chart review, outcomes were compared in two preterm infant groups (25-32 weeks gestation). Infants in Group 1 received surfactant replacement therapy (SRT) via InSurE method, while infants in Group 2 received SRT via LISA method.

RESULTS

Regardless of SRT method utilized, there were no significant differences in rates of BPD between the two groups in infants born at 25-32 weeks gestation (30.6% vs 33.3%; P = 0.47).

CONCLUSIONS

Despite using LISA method rather than InSurE for SRT, premature infants continue to be at high risk for BPD. LISA shows promise as a safe, noninvasive SRT alternative to invasive methods like InSurE.

Long-term outcomes of preterm infants treated with less invasive surfactant technique (LISA)

OBJECTIVE

The aim of this study is to compare the clinical outcomes at 24 months postmenstrual age of two populations receiving beractant replacement therapy using less invasive surfactant administration (LISA) versus intubation, administration of surfactant, and early extubation (INSURE). Hospital admission requirements, psychomotor development, and respiratory and neurological outcomes were studied.

STUDY DESIGN

This was a single-center, retrospective, and descriptive study with a sample of 60 patients (30 for each group) on nasal continuous positive airway pressure during the first 3 days of life, requiring surfactant administration.

RESULTS

We found no significant differences between both groups on psychomotor development and respiratory and neurological outcomes.

CONCLUSION

Compared to INSURE technique, the administration of surfactant by LISA is feasible and safe and reduces invasive mechanical ventilation exposure with no differences in the follow-up neurodevelopmental and respiratory outcomes at 24 postmenstrual age.

The use of less invasive surfactant administration (LISA) in the United States with review of the literature

BACKGROUND

The majority of extremely low gestational age neonates undergo intubation for surfactant therapy. Less invasive surfactant administration (LISA) uses a thin catheter inserted into the trachea to deliver the surfactant. During the procedure, the infant is breathing spontaneously while supported with continuous positive airway pressure. Although LISA is widely adapted in Europe and Australia, the rate of LISA use in the United States is unknown.

STUDY DESIGN

The aim of this study is to evaluate the use of LISA in the US. A web-based survey was distributed via SurveyMonkey to 2550 neonatologists from AAP's SoNPM mailing list.

RESULTS

Of the 472 neonatologists who answered the survey, 15% used LISA either as a part of routine care (8%) or as part of research (7%).

CONCLUSION

Unlike several regions of Europe, LISA is not widely used in the US. Future studies should address ambiguities regarding infant selection, procedure training and "roadblocks" to its broader application.

Update of minimally invasive surfactant therapy

To date, preterm infants with respiratory distress syndrome (RDS) after birth have been managed with a combination of endotracheal intubation, surfactant instillation, and mechanical ventilation. It is now recognized that noninvasive ventilation (NIV) such as nasal continuous positive airway pressure (CPAP) in preterm infants is a reasonable alternative to elective intubation after birth. Recently, a meta-analysis of large controlled trials comparing conventional methods and nasal CPAP suggested that CPAP decreased the risk of the combined outcome of bronchopulmonary dysplasia or death. Since then, the use of NIV as primary therapy for preterm infants has increased, but when and how to give exogenous surfactant remains unclear. Overcoming this problem, minimally invasive surfactant therapy (MIST) allows spontaneously breathing neonates to remain on CPAP in the first week after birth. MIST has included administration of exogenous surfactant by intrapharyngeal instillation, nebulization, a laryngeal mask, and a thin catheter. In recent clinical trials, surfactant delivery via a thin catheter was found to reduce the need for subsequent endotracheal intubation and mechanical ventilation, and improves short-term respiratory outcomes. There is also growing evidence for MIST as an alternative to the INSURE (intubation-surfactant-extubation) procedure in spontaneously breathing preterm infants with RDS. In conclusion, MIST is gentle, safe, feasible, and effective in preterm infants, and is widely used for surfactant administration with noninvasive respiratory support by neonatologists. However, further studies are needed to resolve uncertainties in the MIST method, including infant selection, optimal surfactant dosage and administration method, and need for sedation.

Surfactant administration via a thin endotracheal catheter during spontaneous breathing in preterm infants

To systematically review the clinical outcomes of surfactant administration via a thin endotracheal catheter during spontaneous breathing compared with conventional administration involving tracheal intubation, mechanical ventilation (MV), and tracheal extubation, in preterm infants. PubMed, EMBASE, and the Cochrane Library were searched to identify relevant clinical trials. Data were analyzed using the Cochrane Collaboration methods. Primary outcome measures included the incidence of MV and bronchopulmonary dysplasia (BPD). Finally, four RCTs, two prospective cohort trials, and six historical controlled trials involving 5,261 preterm infants were analyzed. In RCTs, surfactant administration though a thin catheter reduced the incidence of MV (risk ratio [RR]: 0.74; 95% confidence interval [CI]: 0.66, 0.81) in 72 hr and BPD (RR: 0.69, 95%CI: 0.50, 0.97) compared with conventional administration and in non-RCTs, there was also significant reduction in the incidence of MV (RR: 0.55, 95%CI: 0.45, 0.68) and BPD (RR: 0.70, 95%CI: 0.60, 0.82) in favor of the thin catheter group. There were no significant differences between the two procedures in terms of short-term pulmonary complications, intracranial pathology, necrotizing enterocolitis, retinopathy of prematurity, and mortality. Thus, surfactant administration via a thin endotracheal catheter to preterm infants has promising benefits, including reducing the incidences of MV and BPD, while providing comparable breathing support to conventional administration in MV. Pediatr Pulmonol. 2017; 52:844-854. © 2017 Wiley Periodicals, Inc.

Less Invasive Surfactant Administration Reduces the Need for Mechanical Ventilation in Preterm Infants: A Meta-Analysis

Neonatal respiratory distress syndrome due to surfactant deficiency is associated with high morbidity and mortality in preterm infants, and the use of less invasive surfactant administration (LISA) has been increasingly studied. This meta-analysis found that LISA via thin catheter significantly reduced the need for mechanical ventilation within the first 72 hours (relative risk [RR] = 0.677; P = .021), duration of mechanical ventilation (difference in means [MD] = −39.302 hours; P < .001), duration of supplemental oxygen (MD = −68.874 hours; P < .001), and duration of nasal continuous positive airway pressure (nCPAP; MD = −28.423 hours; P = .010). A trend toward a reduction in the incidence of bronchopulmonary dysplasia was observed (RR = 0.656; P = .141). No significant difference in overall mortality, incidence of pneumothorax, or successful first attempts was observed. LISA via thin catheter significantly reduces the need for mechanical ventilation within the first 72 hours as well as the duration of mechanical ventilation, supplemental oxygen, and nCPAP. LISA via thin catheter appears promising in improving preterm infant outcomes.

Evolution of surfactant therapy for respiratory distress syndrome: past, present, and future

Respiratory distress syndrome (RDS) due to surfactant deficiency is the most common cause of respiratory failure in preterm infants. Tremendous progress has been made since the original description that surfactant deficiency is the major cause of RDS. Surfactant therapy has been extensively studied in preterm infants and has been shown to significantly decrease air leaks and neonatal and infant mortality. Synthetic and animal-derived surfactants from bovine as well as porcine origin have been evaluated in randomized controlled trials. Animal-derived surfactants generally result in faster weaning of respiratory support, shorter duration of invasive ventilation, and decreased mortality when compared to first- or second-generation of synthetic surfactants, but some of the second-generation synthetic surfactants are at least not inferior to the animal-derived surfactants. Using a higher initial dose of porcine derived surfactant may provide better outcomes when compared with using lower doses of bovine surfactants, likely, due to compositional difference and/or the dose. Third-generation synthetic surfactant containing peptide analogs of surfactant protein B and C are currently being studied. Less invasive intra-tracheal surfactant administration techniques in spontaneously breathing neonate receiving noninvasive ventilator support are also being evaluated. In the present era, prophylactic surfactant is not recommended as it may increase the risk of lung injury or death. In the future, surfactants may be used as vector to deliver steroids, or used in combination with molecules, such as, recombinant Club Cell Protein-10 (rhCC-10) to improve pulmonary outcomes. Also, noninvasive surfactant administration techniques, such as aerosolization or atomization of surfactant may play a greater role in the future.

Minimally Invasive Surfactant Therapy and Noninvasive Respiratory Support

Respiratory distress syndrome (RDS) caused by surfactant deficiency is major cause for neonatal mortality and short- and long-term morbidity of preterm infants. Continuous positive airway pressure and other modes of noninvasive respiratory support and intubation and positive pressure ventilation with surfactant therapy are efficient therapies for RDS. Because continuous positive airway pressure can fail in severe surfactant deficiency, and because traditional surfactant therapy requires intubation and positive pressure ventilation, this entails a risk of lung injury. Several strategies to combine noninvasive respiratory therapy with minimally invasive surfactant therapy have been described. Available data suggest that those strategies may improve outcome of premature infants with RDS.

Ancillary therapies to enhance success of non-invasive modes of respiratory support - Approaches to delivery room use of surfactant and caffeine?

During recent decades, non-invasive respiratory support has become popular for treating neonates with respiratory failure. Several prospective randomized controlled trials have been performed to compare use of continuous positive airway pressure (CPAP) as primary respiratory support in preterm infants with respiratory distress syndrome (RDS) to endotracheal intubation, mechanical ventilation and surfactant therapy. Systematic reviews of these studies suggest that routine CPAP at delivery is efficacious in decreasing bronchopulmonary dysplasia (BPD), death, or both. This led to the recommendation to consider CPAP to avoid endotracheal intubation. As surfactant therapy is known to reduce BPD and death, several ways to combine CPAP with surfactant have been described. With the increasing use of CPAP immediately after birth, the early use of caffeine to stimulate respiration has become a point of discussion. This review focuses on different modes of surfactant application during CPAP and on the early use of caffeine as ancillary therapies to enhance CPAP success.