Minimally invasive surfactant therapy failure: risk factors and outcome

Effectiveness and safety profile of introducing less invasive surfactant administration in management of respiratory distress syndrome: A retrospective cohort study in a tertiary neonatal unit in Hong Kong

BACKGROUND

The objective was to evaluate the efficacy of introducing less invasive surfactant administration (LISA) for management of preterm neonates with respiratory distress syndrome (RDS).

METHODS

This was a retrospective cohort study identifying preterm neonates with RDS born between 2017 and 2022 in a tertiary neonatal unit, where LISA was introduced in January 2020. Time trend analysis comparing cohort of neonates born before (2017-2020) and after LISA introduction (2020-2022) was performed. The primary outcomes were incidence and severity of bronchopulmonary dysplasia (BPD). Multivariable regression models were used to estimate the association between introducing LISA to RDS management and health and safety outcomes.

RESULTS

In total, 261 neonates with RDS were included (114 born after LISA was introduced). Neonates receiving invasive surfactant administration had lower gestational age, birth weight, lower Apgar scores, and higher oxygen requirement, compared to those receiving LISA. In the time trend analysis, introduction of LISA was associated with lower incidence of BPD (odds ratio (95% confidence interval) 0.34 (0.16, 0.72)), and lower severity of BPD (0.31 (0.16, 0.59)). Pre- and post-LISA period showed similar treatment safety profiles.

CONCLUSION

Introduction of LISA was associated with improved prognosis in neonates with RDS in Hong Kong.

Comparison of "IN-REC-SUR-E" and LISA in preterm neonates with respiratory distress syndrome: a randomized controlled trial (IN-REC-LISA trial)

BACKGROUND

Surfactant is a well-established therapy for preterm neonates affected by respiratory distress syndrome (RDS). The goals of different methods of surfactant administration are to reduce the duration of mechanical ventilation and the severity of bronchopulmonary dysplasia (BPD); however, the optimal administration method remains unknown. This study compares the effectiveness of the INtubate-RECruit-SURfactant-Extubate (IN-REC-SUR-E) technique with the less-invasive surfactant administration (LISA) technique, in increasing BPD-free survival of preterm infants. This is an international unblinded multicenter randomized controlled study in which preterm infants will be randomized into two groups to receive IN-REC-SUR-E or LISA surfactant administration.

METHODS

In this study, 382 infants born at 24+0-27+6 weeks' gestation, not intubated in the delivery room and failing nasal continuous positive airway pressure (nCPAP) or nasal intermittent positive pressure ventilation (NIPPV) during the first 24 h of life, will be randomized 1:1 to receive IN-REC-SUR-E or LISA surfactant administration. The primary outcome is a composite outcome of death or BPD at 36 weeks' postmenstrual age. The secondary outcomes are BPD at 36 weeks' postmenstrual age; death; pulse oximetry/fraction of inspired oxygen; severe intraventricular hemorrhage; pneumothorax; duration of respiratory support and oxygen therapy; pulmonary hemorrhage; patent ductus arteriosus undergoing treatment; percentage of infants receiving more doses of surfactant; periventricular leukomalacia, severe retinopathy of prematurity, necrotizing enterocolitis, sepsis; total in-hospital stay; systemic postnatal steroids; neurodevelopmental outcomes; and respiratory function testing at 24 months of age. Randomization will be centrally provided using both stratification and permuted blocks with random block sizes and block order. Stratification factors will include center and gestational age (24+0 to 25+6 weeks or 26+0 to 27+6 weeks). Analyses will be conducted in both intention-to-treat and per-protocol populations, utilizing a log-binomial regression model that corrects for stratification factors to estimate the adjusted relative risk (RR).

DISCUSSION

This trial is designed to provide robust data on the best method of surfactant administration in spontaneously breathing preterm infants born at 24+0-27+6 weeks' gestation affected by RDS and failing nCPAP or NIPPV during the first 24 h of life, comparing IN-REC-SUR-E to LISA technique, in increasing BPD-free survival at 36 weeks' postmenstrual age of life.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05711966. Registered on February 3, 2023.

Evaluation of a respiratory care protocol including less invasive surfactant administration in preterm infants

BACKGROUND

Respiratory care protocol including less invasive śsurfactant administration (LISA) in ≤29 weeks' gestational age (GA) infants introduced in October 2018.

METHODS

Retrospective study of infants admitted on continuous positive airway pressure (CPAP) October 2018 to December 2021. Maternal and neonatal variables were compared between infants managed on CPAP with and without LISA. Infants who received LISA and subsequently required mechanical ventilation (MV) within 72 h of life (HOL) [LISA failure (LF)] were compared with those who required no MV [LISA success (LS)].

RESULTS

249 infants were admitted on CPAP, 5 were intubated prior to LISA, 143 required LISA and 101 remained on CPAP without surfactant. Of those receiving LISA, 108 were LS and 35 were LF. Compared to LS, LF infants were of lower GA and birth weight, required higher fractional inspired oxygen (FiO2), and CPAP level at birth, admission, one HOL, and an hour after LISA. Moreover, LF infants had higher mortality and morbidity. Together GA ≤ 25 weeks' and FiO2 ≥ 0.3 an hour after LISA best predicted LF.

CONCLUSIONS

Over 80% of infants admitted on CPAP avoided MV within 72 HOL. Early predictors of LF provide targets for future interventions to decrease need for MV in preterm infants.

IMPACT

Less invasive surfactant administration (LISA) decreases the need for mechanical ventilation (MV) and improves outcomes. However, some infants require MV within 72 h of life (HOL) despite LISA (LISA failure). Over 80% of ≤29 weeks' gestational age (GA) infants can be successfully managed on CPAP with or without surfactant in the first 72 HOL. A combination of factors including ≤25 weeks' GA and fraction of inspired oxygen ≥0.3 an hour after LISA predict LISA failure. Evaluation of a noninvasive respiratory support strategy including LISA provides targets for intervention to decrease need for MV in preterm infants.

LISA Eligibility and LISA Success in Extremely Preterm Infants: A Single-Center Experience

INTRODUCTION

Less invasive surfactant application (LISA) is associated with improved short-term outcomes in preterm infants. Data on LISA eligibility and success for infants <28 weeks of gestation are lacking.

METHODS

Preterm infants <28 weeks of gestation who were born and actively treated in our tertiary care center in 2018 were included in the retrospective study. We assessed baseline characteristics, delivery room (DR) management, LISA success and complications, and short-term outcome.

RESULTS

In total, 57 infants received LISA in the DR. LISA eligibility was 73% at 22 weeks, 88% at 23 weeks, and >90% at gestational ages >24 weeks. LISA was successful in 63% of infants. LISA failure was associated with increased risk for high-grade IVH (OR 17.88), death (OR 10.94), and a reduced chance for survival without complications (OR 8.75).

CONCLUSION

Our report justifies LISA as a mode for surfactant application in preterm infants. It contributes to the call for studies to define risk factors for LISA failure.

Less Invasive Surfactant Administration Compared to Intubation, Surfactant, Rapid Extubation Method in Preterm Neonates: An Umbrella Review

INTRODUCTION

In spontaneously breathing neonates, surfactant can be administered via thin catheter while enabling the own breathing (less invasive surfactant administration [LISA]). Alternatively, the neonate is intubated for surfactant delivery (intubation, surfactant, rapid extubation [INSURE]). Thus, the aim was to provide an overview of the efficacy of the LISA compared to INSURE.

METHODS

We performed an umbrella review of previous meta-analyses including randomized controlled trials. We searched PubMed, Scopus, and Web of Science in July 2023. Two authors screened the search results, and systematic reviews with meta-analyses that focused on LISA versus INSURE were included. One author extracted, and another author validated the extracted data. AMSTAR-2 and ROBIS evaluations were performed by two authors independently.

RESULTS

A total of 9 systematic reviews with meta-analyses were included. The quality according to AMSTAR-2 was high in one, moderate in one, low in three, and critically low in four. According to ROBIS, the risk of bias was low in three and high in six of the reviews. LISA was more effective than INSURE in preventing mechanical ventilation (8/8 reviews), death or BPD (4/4 reviews), death (3/9 reviews), and BPD (3/9 reviews).

CONCLUSIONS

All the included systematic reviews and meta-analyses reported LISA to be more effective than INSURE in terms of need for mechanical ventilation and death or BPD. However, the quality of the published systematic reviews has been mostly deficient. Future systematic reviews should focus on reporting quality.

Ultrasound evaluation of diaphragm kinetics after minimally invasive surfactant administration

PURPOSE

Concerns remain on different alveolar deposition of surfactant between LISA and INSURE methods. Ultrasound evaluation of diaphragm kinetics may provide clinical evidence on this issue, as indirect representation of the respiratory system compliance.

METHODS

This was a prospective-observational pilot study. The inclusion criterion was CPAP-supported infants ≤ 32 weeks with RDS receiving surfactant via minimally invasive technique. 52 patients randomized for surfactant administration via LISA or INSURE methods were enrolled. Right diaphragm (RD) global mean peak velocity (MPV) by Pulsed-Wave Tissue Doppler Imaging (PTDI) was recorded before and two hours after surfactant administration with simultaneous measurements of oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) (SF ratio). Mechanical ventilation ≤ 72 h from birth represented treatment failure.

RESULTS

LISA infants had significantly higher gestational age (p = 0.029) and birth weight (p = 0.030) with lower CRIB-II scores (p = 0.030) than INSURE infants. LISA infants showed higher median MPV at baseline RD-PTDI US assessment (p = 0.024), but post-surfactant median MPV and other the investigated variables were similar at the adjusted analysis for gestational age and sedation. 8/52 (15%) infants who failed treatment had a significantly lower SF ratio (p = 0.002) and higher median MPV at RD-PTDI US (p = 0.004) after surfactant administration, despite the higher CPAP support level before (p = 0.007) and after (p = 0.001) surfactant administration. A full course of antenatal steroids was protective against mechanical ventilation (p = 0.038).

CONCLUSIONS

Different minimally invasive surfactant administration techniques do not appear to influence diaphragm kinetics evaluated by RD-PTDI US.

Timing of surfactant treatment in respiratory distress syndrome

The introduction of exogenous surfactant in the 1980s has resulted in an improved survival of very preterm infants with respiratory distress syndrome (RDS). Randomized controlled trials conducted before 2000 have shown that the magnitude of this beneficial effect strongly depends on the timing of surfactant treatment, i.e. the earlier surfactant is administered after birth the better. However, the initial mode of respiratory support in infants with RDS has changed dramatically over the last decades, moving from invasive to non-invasive support. Furthermore, new, less invasive techniques to administer surfactant have been introduced to match this non-invasive approach. This review summarizes the evidence on how these practice changes impacted the effect of surfactant timing on mortality and morbidity in preterm infants with RDS.

Predicting CPAP failure after less invasive surfactant administration (LISA) in preterm infants by machine learning model on vital parameter data: a pilot study

Objective. Less invasive surfactant administration (LISA) has been introduced to preterm infants with respiratory distress syndrome on continuous positive airway pressure (CPAP) support in order to avoid intubation and mechanical ventilation. However, after this LISA procedure, a significant part of infants fails CPAP treatment (CPAP-F) and requires intubation in the first 72 h of life, which is associated with worse complication free survival chances. The aim of this study was to predict CPAP-F after LISA, based on machine learning (ML) analysis of high resolution vital parameter monitoring data surrounding the LISA procedure.Approach. Patients with a gestational age (GA) <32 weeks receiving LISA were included. Vital parameter data was obtained from a data warehouse. Physiological features (HR, RR, peripheral oxygen saturation (SpO2) and body temperature) were calculated in eight 0.5 h windows throughout a period 1.5 h before to 2.5 h after LISA. First, physiological data was analyzed to investigate differences between the CPAP-F and CPAP-Success (CPAP-S) groups. Next, the performance of two types of ML models (logistic regression: LR, support vector machine: SVM) for the prediction of CPAP-F were evaluated.Main results. Of 51 included patients, 18 (35%) had CPAP-F. Univariate analysis showed lower SpO2, temperature and heart rate variability (HRV) before and after the LISA procedure. The best performing ML model showed an area under the curve of 0.90 and 0.93 for LR and SVM respectively in the 0.5 h window directly after LISA, with GA, HRV, respiration rate and SpO2as most important features. Excluding GA decreased performance in both models.Significance. In this pilot study we were able to predict CPAP-F with a ML model of patient monitor signals, with best performance in the first 0.5 h after LISA. Using ML to predict CPAP-F based on vital signals gains insight in (possibly modifiable) factors that are associated with LISA failure and can help to guide personalized clinical decisions in early respiratory management.

Prevention of Chronic Morbidities in Extremely Premature Newborns with LISA-nCPAP Respiratory Therapy and Adjuvant Perinatal Strategies

Less invasive surfactant administration techniques, together with nasal continuous airway pressure (LISA-nCPAP) ventilation, an emerging noninvasive ventilation (NIV) technique in neonatology, are gaining more significance, even in extremely premature newborns (ELBW), under 27 weeks of gestational age. In this review, studies on LISA-nCPAP are compiled with an emphasis on short- and long-term morbidities associated with prematurity. Several perinatal preventative and therapeutic investigations are also discussed in order to start integrated therapies as numerous organ-saving techniques in addition to lung-protective ventilations. Two thirds of immature newborns can start their lives on NIV, and one third of them never need mechanical ventilation. With adjuvant intervention, these ratios are expected to be increased, resulting in better outcomes. Optimized cardiopulmonary transition, especially physiologic cord clamping, could have an additively beneficial effect on patient outcomes gained from NIV. Organ development and angiogenesis are strictly linked not only in the immature lung and retina, but also possibly in the kidney, and optimized interventions using angiogenic growth factors could lead to better morbidity-free survival. Corticosteroids, caffeine, insulin, thyroid hormones, antioxidants, N-acetylcysteine, and, moreover, the immunomodulatory components of mother's milk are also discussed as adjuvant treatments, since immature newborns deserve more complex neonatal interventions.

Should less invasive surfactant administration (LISA) become routine practice in US neonatal units?

The harmful effects of mechanical ventilation (MV) on the preterm lung are well established. Avoiding MV at birth and stabilization on continuous positive airway pressure (CPAP) decreases the composite outcome of death or bronchopulmonary dysplasia. Although preterm infants are increasingly being admitted to the neonatal intensive care unit on CPAP, centers differ in the ability to manage infants primarily on CPAP. Over the last decade, less invasive surfactant administration (LISA), a method of administering surfactant with a thin catheter, has been devised and has been shown to decrease the need for MV and improve outcomes compared to surfactant administration via an endotracheal tube following intubation. While LISA has been widely adopted in Europe and other countries, its use is not widespread in the United States. This article provides a summary of the existing evidence on LISA, and practical guidance for US units choosing to implement a change of practice incorporating optimization of CPAP and LISA. IMPACT: The accumulated body of evidence for less invasive surfactant administration (LISA), a widespread practice in other countries, justifies its use as an alternative to intubation and surfactant administration in US neonatal units. This article summarizes the current evidence for LISA, identifies gaps in knowledge, and offers practical tips for the implementation of LISA as part of a comprehensive non-invasive respiratory support strategy. This article will help neonatal units in the US develop guidelines for LISA, provide optimal respiratory support for infants with respiratory distress syndrome, improve short- and long-term outcomes of preterm infants, and potentially decrease costs of NICU care.

Respiratory Management of the Preterm Infant: Supporting Evidence-Based Practice at the Bedside

Extremely preterm infants frequently require some form of respiratory assistance to facilitate the cardiopulmonary transition that occurs in the first hours of life. Current resuscitation guidelines identify as a primary determinant of overall newborn survival the establishment, immediately after birth, of adequate lung inflation and ventilation to ensure an adequate functional residual capacity. Any respiratory support provided, however, is an important contributing factor to the development of bronchopulmonary dysplasia. The risks correlated to invasive ventilatory techniques increase inversely with gestational age. Preterm infants are born at an early stage of lung development and are more susceptible to lung injury deriving from mechanical ventilation. Any approach aiming to reduce the global burden of preterm lung disease must implement lung-protective ventilation strategies that begin from the newborn’s first breaths in the delivery room. Neonatologists today must be able to manage both invasive and noninvasive forms of respiratory assistance to treat a spectrum of lung diseases ranging from acute to chronic conditions. We searched PubMed for articles on preterm infant respiratory assistance. Our narrative review provides an evidence-based overview on the respiratory management of preterm infants, especially in the acute phase of neonatal respiratory distress syndrome, starting from the delivery room and continuing in the neonatal intensive care unit, including a section regarding exogenous surfactant therapy.

Prediction of surfactant requirement in Indian preterm infants by lung ultrasound scores: a diagnostic accuracy study from a developing country

The purpose of this study is to validate lung ultrasound score (LUS) for prediction of surfactant replacement therapy (SRT) in Indian infants of 27-33^6/7 weeks gestational age (GA). This prospective diagnostic accuracy study was conducted in a level 3 neonatal care unit in India. Consecutively born preterm infants with respiratory distress syndrome (RDS) were enrolled. Surfactant was administered if oxygen requirement exceeded > 30%. Baseline characteristics, respiratory parameters, and lung ultrasound images were recorded soon after admission and compared between surfactant and non-surfactant groups. Adjusted odds ratio (OR) and diagnostic accuracy of LUS were calculated for SRT. Among 78 infants with RDS included in the final analysis, 62 received surfactant (79.48%). Median time of performing lung ultrasound was 50 min of life in both groups. Median LUS in the anterior and posterior chest areas of either side as well as total LUS was significantly higher in the surfactant group. After adjusting for other confounders, LUS was found to be a significant predictor of SRT (adjusted OR (95%CI): 1.55 (1.15-2.087)). Diagnostic accuracy of LUS was determined by receiver operating characteristic (ROC) curve analysis (AUC (95% CI): 0.751 (0.64-0.842), p < 0.001). A cutoff score of ≥ 9 for LUS was considered optimal for SRT (sensitivity (95%CI): 70.97% (57.87-81.45), specificity (95%CI): 68.75% (41.48-87.87)).

CONCLUSION

Lung ultrasound is a valid diagnostic tool for SRT in Indian setting with a cutoff score ≥ 9.

TRIAL REGISTRATION

CTRI/2021/11/038269.

WHAT IS KNOWN

• Surfactant requirement in preterm infants with RDS has been traditionally based on FiO2 criteria. • Lung ultrasound score can predict the need for surfactant although majority of the studies originated in developed countries.

WHAT IS NEW

• Lung ultrasound is a valid tool for surfactant replacement therapy even in developing countries like India.

A pilot study of evaluation of semi-rigid and flexible catheters for less invasive surfactant administration in preterm infants with respiratory distress syndrome—a randomized controlled trial

Background

In respiratory distress syndrome, many neonatology centers worldwide perform minimal invasive surfactant application in premature infants, using small-diameter catheters for endotracheal intubation and surfactant administration.

Methods

In this single-center, open-label, randomized-controlled trial, preterm infants requiring surfactant administration after birth, using a standardized minimal invasive protocol, were randomized to two different modes of endotracheal catheterization: Flexible charrière-4 feeding tube inserted using Magill forceps (group 1) and semi-rigid catheter (group 2). Primary outcome was duration of laryngoscopy. Secondary outcomes were complication rate (intraventricular hemorrhage, soft-tissue damage in first week of life) and vital parameters during laryngoscopy. Between 2019 and 2020, 31 infants were included in the study. Prior to in-vivo testing, laryngoscopy durations were studied on a neonatal airway mannequin in students, nurses and doctors.

Results

Mean gestational age and birth weight were 27 + 6/7 weeks and 1009 g; and 28 + 0/7 weeks and 1127 g for group 1 and 2, respectively. Length of laryngoscopy was similar in both groups (61.1 s and 64.9 s) overall (p.77) and adjusted for weight (p.70) or gestational age (p.95). Laryngoscopy failed seven times in group 1 (43.8%) and four times (26.7%) in group 2 (p.46). Longer laryngoscopy was associated with lower oxygen saturation with lowest levels occurring after failed laryngoscopy attempts. Secondary outcomes were similar in both groups. In vitro data on 40 students, 40 nurses and 12 neonatologists showed significant faster laryngoscopy in students and nurses group 2 (p < .0001) unlike in neonatologists (p.13).

Conclusion

This study showed no difference in laryngoscopy duration in endotracheal catheterization when comparing semi-rigid and flexible catheters for minimal invasive surfactant application in preterm infants. In accordance with preliminary data and in contrast to published in-vitro trials, experienced neonatologists were able to perform endotracheal catheterization using both semi-rigid and flexible catheters at similar rates and ease, in vitro and in vivo.

Trial registration

ClinicalTrials.gov. NCT05024435 Registered 27 August 2021—Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03714-3.

Less Invasive Surfactant Administration: A Review of Current Evidence of Clinical Outcomes With Beractant

Evidence supporting clinical recommendations or approval for less invasive surfactant administration (LISA) has primarily examined heterogeneous or small-volume (e.g., 1.25-2.5 mL/kg) animal-derived surfactant regimens. To address the evidence gap for larger-volume (e.g., 4-5 mL/kg) animal-derived surfactants, the aim of this review was to evaluate and summarize LISA literature for widely used larger-volume beractant. Surfactant treatment and the LISA technique were initially summarized. The available literature on beractant with LISA was thoroughly assessed and reviewed, including a recent systematic analysis, studies from regions where access or preferences may influence reliance on larger-volume surfactants, and investigations of short- and long-term outcomes. The available literature indicated improved short-term outcomes, including less need for mechanical ventilation, death, or bronchopulmonary dysplasia, and no negative long-term developmental outcomes when beractant was administered via LISA compared with older, more invasive techniques. The rates of short-term outcomes were similar to those previously observed in examinations of LISA with small-volume surfactants, including in populations reflecting very preterm infants. As uptake of LISA is expected to increase, future research directions for larger-volume surfactants include cost-effectiveness evaluations and robust examinations of repeat dosing and surfactant reflux to further inform clinical practice. This review provides a detailed assessment of the literature describing surfactant and LISA, with a focus on studies of beractant. Collectively, the available evidence supports the use of beractant with LISA based both on short-term and long-term outcomes relative to more invasive techniques and comparability of outcomes with small-volume surfactants and may be valuable in guiding clinical decision-making.

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.

Association of Administration of Surfactant Using Less Invasive Methods With Outcomes in Extremely Preterm Infants Less Than 27 Weeks of Gestation

IMPORTANCE

The inclusion of less invasive surfactant administration (LISA) in the care of preterm infants has been found to be beneficial for respiratory outcomes. Recently, the OPTIMIST trial found higher mortality rates in the subgroup of infants born at 25 to 26 weeks' gestational age (GA) who received surfactant treatment while spontaneously breathing.

OBJECTIVE

To analyze outcomes among LISA-exposed, highly vulnerable babies born at less than 27 weeks' GA within the large-scale observational cohort of the German Neonatal Network.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study of data from 68 tertiary level neonatal intensive care units in Germany of infants born between 22 weeks 0 days to 26 weeks 6 days of gestation between April 1, 2009, and December 31, 2020, short-term outcomes among infants receiving LISA vs infants not receiving LISA were compared.

EXPOSURE

Use of LISA within the first 72 hours of life.

MAIN OUTCOMES AND MEASURES

The main outcomes were rates of LISA use, use of mechanical ventilation within the first 72 hours (considered failure of LISA), and association of LISA with outcomes, including death from all causes, bronchopulmonary dysplasia (BPD), death and BPD combined, pneumothorax, retinopathy of prematurity, intracerebral hemorrhage, and periventricular leukomalacia. To address potential confounding factors, multivariate logistic regression models were used.

RESULTS

A total of 6542 infants (3030 [46.3%] female and 3512 [53.7%] male; mean [SD] GA, 25.3 (1.1) weeks; mean [SD] birth weight, 715 [180] g) were analyzed; 2534 infants (38.7%) received LISA, which was most frequently given quasi-prophylactically during delivery room management. Among the infants who received LISA, 1357 (53.6%) did not require mechanical ventilation in the first 72 hours compared with 331 infants (8.3%) of 4008 who did not receive LISA. In a multivariate logistic regression model that adjusted for GA, small-for-GA status, sex, multiple birth, inborn status, antenatal steroid use, and maximum fraction of inspired oxygen in the first 12 hours of life, LISA was associated with reduced risks of all-cause death (odds ratio [OR], 0.74; 95% CI, 0.61-0.90; P = .002), BPD (OR, 0.69; 95% CI, 0.62-0.78; P < .001), and BPD or death (OR, 0.64; 95% CI, 0.57-0.72; P < .001) compared with infants without LISA exposure.

CONCLUSIONS AND RELEVANCE

The results of this long-term multicenter cohort study suggest that LISA may be associated with reduced risks of adverse outcomes in extremely preterm infants.

Incidence, predictors of success and outcome of LISA in very preterm infants

OBJECTIVES

The aim of this study was to examine the success rate of less invasive surfactant administration (LISA), to identify early predictive factors for the outcome of LISA, and to compare neonatal outcomes between the LISA failure group and the group of infants who were successfully treated with LISA.

DESIGN

A retrospective cohort study.

PATIENTS

Infants born at less than 33 weeks of gestation (n = 158) and treated with LISA for respiratory distress syndrome.

RESULTS

LISA was successful in 86 cases (54.4%); 72 preterm infants (45.6%) needed additional surfactant therapy and/or mechanical ventilation in the first 72 h (LISA failure). In a multivariate logistic regression analysis, six independent predictors of LISA success were identified: core temperature at the time of admission (adjusted odds ratio (OR): 3.56), dose of poractant alfa (<200 mg/kg; adjusted OR: 0.254), elevated C-reactive protein (>10 mg/L) at 24 h of life (adjusted OR: 0.28), highest respiratory severity score (RSS) during the first hour of life or at the time of LISA (adjusted OR: 0.463), maternal age (adjusted OR: 0.923), and birth weight (adjusted OR: 1.003). The receiver operating curve created by using the identified factors indicates good predictive power with an area under the curve of 0.85. LISA failure was associated with a substantially higher risk of complications.

CONCLUSION

LISA success can be predicted by variables available before the intervention. Failure of LISA is relatively frequent event in very preterm infants and is associated with adverse outcomes. Prevention of hypothermia during early stabilization and appropriate dosing of surfactant may increase LISA success rates and improve patient outcome.

Neonatal Preterm Respiratory Care in Ukraine: An Observational Study of Outcomes in Relation to Timing and Methods of Surfactant Treatment

OBJECTIVE

Timely and effective noninvasive respiratory support and surfactant administration are the key determinants of clinical outcomes in very preterm infants. The objective of this study was to evaluate the impact of the changes in clinical practice of surfactant administration on clinical outcomes and the incidence of continuous positive airway pressure (CPAP) failure defined as the need for mechanical ventilation (MV) during the first 5 days of life in preterm infants <32 weeks.

STUDY DESIGN

One hundred sixty-five outborn very preterm infants with respiratory distress syndrome (RDS), initially managed on CPAP, were enrolled in a retrospective cohort study. Fifty-two infants treated with surfactant using less invasive or INSURE technique were included in the surfactant group. One hundred thirteen control infants received surfactant only in case of CPAP failure.

RESULTS

The study groups were similar in gestational age, rates of main obstetric complications, and antenatal steroid prophylaxis. The rate of cesarean delivery was significantly higher but birth weight and need for resuscitation were lower in infants from the surfactant group. Fifty-five infants with CPAP failure (49%) received surfactant after initiation of MV in the control group in comparison with 52 (100%) in the surfactant group (p < 0.001). The incidence of CPAP failure was significantly higher in the control group (49 vs. 27%; p < 0.01) and it occurred earlier (median [interquartile range age: 4 [2-5] vs. 47 [36-99] hours, respectively; p < 0.001). Early surfactant administration significantly and independently affected the probability of CPAP failure (adjusted odds ratio: 0.29, 95% confidence interval: 0.13-0.67; p < 0.01). There were no differences in morbidities between the groups, but CPAP failure was significantly associated with higher morbidity and mortality.

CONCLUSION

Adherence to the European RDS guidelines with early rescue, less invasive surfactant administration in very preterm infants decreased the probability of CPAP failure which was significantly associated with higher morbidity and mortality.

KEY POINTS

· Early surfactant decreases the probability of CPAP failure.. · Timing and methods of surfactant administration are important.. · Randomized comparisons of prophylactic LISA and CPAP are needed..

Comparison of minimally invasive surfactant therapy with intubation surfactant administration and extubation for treating preterm infants with respiratory distress syndrome: a randomized clinical trial

BACKGROUND

Respiratory distress syndrome (RDS) is a common cause of hospitalization and death in preterm infants who require surfactant treatment and respiratory support.

PURPOSE

This study aimed to compare the clinical outcomes of minimally invasive surfactant therapy (MIST) and the INtubation, SURfactant administration, and Extubation (INSURE) technique in preterm infants with RDS.

METHODS

In this clinical trial, 112 preterm infants born at 28-36 weeks of gestation and diagnosed with RDS randomly received 200-mg/kg surfactant by MIST or the INSURE method. In the MIST group, surfactant was administered using a thin catheter (5F feeding tube); in the INSURE group, surfactant was administered after intubation using a feeding tube and the tracheal tube was removed after positive pressure ventilation was started. Nasal continuous positive airway pressure was applied in both groups for respiratory support and the postprocedure clinical outcomes were compared.

RESULTS

The mean hospitalization time was shorter for infants in the MIST group than for those in the INSURE group (9.19± 1.72 days vs. 10.21±2.15 days, P=0.006). Patent ductus arteriosus was less frequent in the MIST group (14.3% vs. 30.4%, P=0.041). Desaturation during surfactant administration occurred less commonly in the MIST group (19.6% vs. 39.3%, P=0.023). There were no significant intergroup differences in other early or late complications.

CONCLUSION

These results suggest that surfactant administration using MIST could be a good replacement for INSURE in preterm infants with RDS since its use reduced the hospitalization time and the number of side effects.

Outcomes following less-invasive-surfactant-administration in the delivery-room

BACKGROUND

Less invasive surfactant administration (LISA) on the neonatal unit reduces the need for mechanical ventilation and bronchopulmonary dysplasia (BPD).

AIMS

To assess the immediate and longer-term efficacy of LISA to prematurely born infants in the delivery-room.

STUDY DESIGN

A case control study with inborn historical controls matched for gestational age, birthweight and gender to each LISA infant.

SUBJECTS

Infants born between 26⁺⁰ weeks and 34⁺⁶ weeks of gestational age.

OUTCOME MEASURES

Respiratory function monitoring before and after LISA and need for mechanical ventilation within 72 h of birth.

RESULTS

Ninety-nine infants, median gestational age of 32⁺⁴(range:27⁺⁰-34⁺⁶) weeks, were prospectively recruited. The respiratory rate and inspired oxygen (FiO₂) decreased two minutes after LISA and there was a reduction in the FiO₂ requirement at two hours post birth. Compared to historical controls, LISA administration was associated with a reduction in the need for mechanical ventilation within 72 h after birth (20.2% versus 56.6% p < 0.001) the incidence of moderate to severe BPD (8.2% versus 20.2%, p = 0.02) and the median costs of neonatal intensive care stay (£1218 versus £2436, p = 0.03) and total neonatal unit stay (£12,888 versus £17,240, p = 0.04). A high FiO₂ in the delivery-room pre-LISA (median 0.75 versus 0.60, p = 0.02) was associated with LISA failure, that is mechanical ventilation within 72 h of birth.

CONCLUSIONS

LISA to prematurely born infants in the delivery-room was associated with reductions in the need for mechanical ventilation and costs of care, but was less successful in those with initial, more severe respiratory disease.

Alternative Methods of Surfactant Administration in Preterm Infants with Respiratory Distress Syndrome: State of the Art

For preterm infants with respiratory distress syndrome, delivery of surfactant via brief intubation (INtubate, SURfactant, Extubate; InSurE) has been the standard technique of surfactant administration. However, this method requires intubation and positive pressure ventilation. It is thought that even the short exposure to positive pressure inflations may be enough to initiate the cascade of events that lead to lung injury in the smallest neonates. In an effort to avoid tracheal intubation and positive pressure ventilation, several alternative and less invasive techniques of exogenous surfactant administration have been developed over the years. These have been investigated in clinical studies, including randomized clinical trials, and have demonstrated advantages such as a decrease in the need for mechanical ventilation and incidence of bronchopulmonary dysplasia. These newer techniques of surfactant delivery also have the benefit of being easier to perform. Surfactant delivery via pharyngeal instillation, laryngeal mask, aerosolization, and placement of a thin catheter are being actively pursued in research. We present a contemporary review of surfactant administration for respiratory distress syndrome via these alternative methods in the hope of guiding physicians in their choices for surfactant application in the neonatal intensive care unit.

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.

Minimally invasive surfactant therapy versus intubation for surfactant delivery in preterm infant with RDS: evaluation of safety and efficacy

BACKGROUND

Minimally invasive surfactant therapy (MIST) is a promising mode of administration that offers the potential to limit barotrauma and prevent lung injury in preterm infants with respiratory distress syndrome (RDS).

OBJECTIVE

This study assessed the effects of the implementation of MIST on safety and efficacy in infants who met criteria for surfactant administration and were treated by MIST as compared with a historical control group treated with surfactant via an endotracheal tube during mechanical ventilation.

METHODS

This retrospective study included infants born between 2012 and 2017 who met the following inclusion criteria: gestational age 23-36 + 6 weeks, a diagnosis of RDS requiring at least 30% oxygen with or without nasal continuous positive airway pressure (nCPAP). MIST was introduced in 2014 and a comparison was made between the study group who received MIST and the control group who met similar criteria and received surfactant via an endotracheal tube during mechanical ventilation.

RESULTS

No significant differences were found between the groups in baseline and demographic data. Severity of initial disease, assessed by the CRIB II score, was similar in the two groups (control 4.6 ± 2.8, MIST 4.4 ± 2.4, p=.995). The requirement for oxygen during the first 3 d of life was significantly lower (area under the curve [AUC]: p=.001) in the MIST group as assessed by the AUC. Likewise, the mean days of oxygen requirement were significantly lower in the MIST group (Control: 10.3 d, MIST: 5.9 d, p=.04). Only six infants in the MIST group (13%) subsequently required intubation for mechanical ventilation, only one of whom adjacent to the procedure. A modest reduction in duration of ventilation was also noted. Duration of admission was 32 ± 23 d in the control group and 26 ± 21 d in the MIST group, p=.061. No significant differences were found between the groups in the incidence of major morbidities or mortality. No major adverse events related to the procedure were observed.

CONCLUSIONS

Transition to MIST was associated with significantly reduced need for oxygen, mechanical ventilation and surfactant, and a borderline shortened NICU admission.

Survival and causes of death in extremely preterm infants in the Netherlands

OBJECTIVE

In the Netherlands, the threshold for offering active treatment for spontaneous birth was lowered from 25⁺⁰ to 24⁺⁰ weeks' gestation in 2010. This study aimed to evaluate the impact of guideline implementation on survival and causes and timing of death in the years following implementation.

DESIGN

National cohort study, using data from the Netherlands Perinatal Registry.

PATIENTS

The study population included all 3312 stillborn and live born infants with a gestational age (GA) between 24^0/7 and 26^6/7 weeks born between January 2011 and December 2017. Infants with the same GA born between January 2007 and December 2009 (N=1400) were used as the reference group.

MAIN OUTCOME MEASURES

Survival to discharge, as well as cause and timing of death.

RESULTS

After guideline implementation, there was a significant increase in neonatal intensive care unit (NICU) admission rate for live born infants born at 24 weeks' GA (27%-69%, p<0.001), resulting in increased survival to discharge in 24-week live born infants (13%-34%, p<0.001). Top three causes of in-hospital mortality were necrotising enterocolitis (28%), respiratory distress syndrome (19%) and intraventricular haemorrhage (17%). A significant decrease in cause of death either complicated or caused by respiratory insufficiency was seen over time (34% in 2011-2014 to 23% in 2015-2017, p=0.006).

CONCLUSIONS

Implementation of the 2010 guideline resulted as expected in increased NICU admissions rate and postnatal survival of infants born at 24 weeks' GA. In the years after implementation, a shift in cause of death was seen from respiratory insufficiency towards necrotising enterocolitis and sepsis.

Respiratory monitoring during less invasive surfactant administration in the delivery suite

BACKGROUND

On the neonatal unit less invasive surfactant administration (LISA) reduces BPD and the need for mechanical ventilation.

AIMS

To evaluate the feasibility of LISA in the delivery suite and to undertake respiratory function physiological monitoring before and after LISA.

STUDY DESIGN

A prospective, observational cohort study was undertaken. A LISA simulation training programme was delivered. Then, LISA was undertaken in infants with respiratory distress maintained on continuous positive airway pressure (CPAP) in the delivery suite using videolaryngoscopic guidance without sedation.

SUBJECTS

Thirty-eight infants with a median (IQR) gestational age of 31 + ⁵ weeks (30⁺³-33⁺⁴) and birth weight of 1.61 (1.42-1.90) kg had LISA in the delivery suite.

OUTCOME MEASURES

Adverse effects of LISA and whether LISA resulted in changes in tidal and minute volumes, end tidal carbon dioxide (EtCO₂) levels and the inspired oxygen concentration (FiO₂).

RESULTS

Respiratory function monitoring was available for 34 of the infants. LISA occurred at a median (IQR) interval of 18 (15-29) minutes after birth. The most common adverse events were desaturation (44.7%) and surfactant reflux (39.5%), both responded to either temporary suspension of LISA or slowing the speed of surfactant administration. Following LISA, there was a significant reduction in respiratory rate 2 min later (p < 0.001) and in the FiO₂ 2 h later (p < 0.001).

CONCLUSIONS

LISA is feasible in the delivery suite after appropriate training of staff. It can be undertaken without serious adverse effects and results in a reduction in respiratory distress and improvement in oxygenation.

A systematic review of reports of quality improvement for bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the most common morbidity of preterm infants, and its incidence has not responded to research and intervention efforts to the same degree as other major morbidities associated with prematurity. The complexity of neonatal respiratory care as well as persistent inter-institutional variability in BPD rates suggest that BPD may be amenable to quality improvement (QI) efforts. We present a systematic review of QI for BPD in preterm infants. We identified 22 reports from single centers and seven from collaborative efforts published over the past two decades. In almost all of the reports, respiratory QI interventions successfully reduced BPD or other key respiratory measures, particularly for infants with birth weight over 1000 g. Several themes and lessons from existing reports may help inform future efforts in both research and QI to impact the burden of BPD.

Outcomes after Introduction of Minimally Invasive Surfactant Therapy in Two Australian Tertiary Neonatal Units

OBJECTIVE

To assess the procedural and clinical outcomes associated with the introduction of minimally invasive surfactant therapy (MIST) into standard care at 2 tertiary Australian neonatal intensive care units.

STUDY DESIGN

A prospective audit was designed before the introduction of MIST in 2018, with data collected over a period of 18 months. Procedural data were completed by the clinical team performing MIST, including clinical observations, medication use, and adverse events. The audit team collected demographic data and subsequent clinical outcomes from medical records.

RESULTS

There were 135 MIST procedures recorded in 122 infants. For the included infants, the median gestation was 30^2/7 weeks (IQR, 27^6/7 to 32^2/7 weeks) and birth weight was 1439 g (IQR, 982-1958 g). During the MIST procedure, desaturation to a peripheral oxygen saturation of <80% was common, occurring in 75.2% of procedures. Other adverse events included need for positive pressure ventilation (10.6%) and bradycardia <100 beats per minute (13.3%). The use of atropine premedication was associated with a significantly lower incidence of bradycardia: 8.6% vs 52.9% (P < .01). Senior clinicians demonstrated higher rates of procedural success. The majority of infants (63.9%) treated with MIST did not require subsequent intubation and mechanical ventilation.

CONCLUSIONS

MIST can be successfully introduced in neonatal units with limited experience of this technique. The use of atropine premedication decreases the incidence of bradycardia during the procedure. Success rates can be optimized by limiting MIST to clinicians with greater competence in endotracheal intubation.

Lung ultrasound for early surfactant treatment: Development and validation of a predictive model

AIM

To develop and validate a feasible predictive model for early surfactant treatment in very preterm infants (VPI) admitted with respiratory distress syndrome (RDS).

METHODS

Preterm infants less than 32 weeks of gestation with RDS and stabilized with noninvasive ventilation in delivery room were recruited (January 2018-April 2020). Clinical data, chest X-ray (CXR) score, respiratory support, oxygen saturation/fraction of inspired oxygen ratio (SF ratio), lung ultrasound (LUS) score, and diaphragmatic thickening fraction (DTF) were recorded at 60-120 min of life. Oxygen threshold for surfactant administration was fraction of inspired oxygen more than 30%; ultrasound findings were blinded. Logistic regression models using a stepwise selection of variables were developed in the derivation cohort. Coefficients from these models were applied to the validation cohort and a diagnostic performance was calculated.

RESULTS

A total of 144 VPI with a mean gestational age of 28.7 ± 2.2 weeks were included (94 into the derivation cohort, 50 into the validation cohort); 37 required surfactant treatment (25.7%). Gestational age, SF ratio, LUS score, CXR score, and Silverman score were related to surfactant administration (R²  = .823). Predictors included in the final model for surfactant administration were SF ratio and LUS score (R²  = .783) with an area under the receiver operating characteristic (AUC) = 0.97 (95% confidence interval [CI]: 0.93-1.00) in the derivation cohort and an AUC = 0.95 (95% CI: 0.85-0.99) in the validation cohort. By applying our predictive model, 26 patients (70.2%) would have been treated with surfactant earlier than 2 h of life.

CONCLUSION

The predictive model showed a high diagnostic performance and could be of value to optimize early respiratory management in VPI with RDS.

Modified lung ultrasound score predicts ventilation requirements in neonatal respiratory distress syndrome

Background

We propose a modified lung ultrasound (LUS) score in neonates with respiratory distress syndrome (RDS), which includes posterior instead of lateral lung fields, and a 5-grade rating scale instead of a 4-grade rating scale. The purpose of this study was to evaluate the reproducibility of the rating scale and its correlation with blood oxygenation and to assess the ability of early post-birth scans to predict the mode of respiratory support on day of life 3 (DOL 3). As a secondary objective, the weight of posterior scans in the overall LUS score was assessed.

Methods

We analyzed 619 serial lung scans performed in 70 preterm infants < 32 weeks gestation and birth weight < 1500 g. Assessments were performed within 24 h of birth (LUS₀) and on days 2, 3, 5, 7, 10, 14, 21 and 28. LUS scores were correlated with oxygen saturation over fraction of inspired oxygen (S/F) and mode of respiratory support. Interrater agreement was determined with the intraclass correlation coefficient (ICC) and Cronbach’s alpha. Probabilities of the need for various respiratory support modes on DOL 3 were assessed with ordinal logistic regression. Least square (ls) means of the posterior and anterior pulmonary field scores were compared.

Results

The LUS score correlated significantly with S/F (Spearman rho = −0.635; p < 0.0001) and had excellent interrater agreement (ICC = 0.94, 95% CI 0.93–0.95; Cronbach’s alpha = 0.99). Significant predictors of ventilation requirements on DOL 3 were LUS₀ (p < 0.016) and birth weight (BW) (p < 0.001). In the ROC analysis, LUS₀ had high reliability in prognosing invasive ventilation on DOL 3 (AUC = 0.845 (95% DeLong CI: 0.738–0.951; p < 0.001)). Invasive ventilation was the most likely mode of respiratory support for LUS₀ scores: ≥7 (in infants with BW 900 g), ≥ 10 (in infants with BW 1050 g) and ≥ 15 (in infants with BW 1280 g). Posterior fields exhibited significantly higher average scores than anterior fields. Respective ls means (confidence levels) were 4.0 (3.8–4.1) vs. 2.2 (2.0–2.4); p < 0.001.

Conclusions

Post-birth LUS predicts ventilation requirements on DOL 3. Scores of posterior pulmonary fields have a predominant weight in the overall LUS score.

FiO2 Before Surfactant, but Not Time to Surfactant, Affects Outcomes in Infants With Respiratory Distress Syndrome

Aim: To establish the impact of oxygen requirement before surfactant (SF) and time from birth to SF administration on treatment outcomes in neonatal respiratory distress syndrome (RDS). Methods: We conducted a post-hoc analysis of data from a prospective cohort study of 500 premature infants treated with less invasive surfactant administration (LISA). LISA failure was defined as the need for early (<72 h of life) mechanical ventilation (MV). Baseline clinical characteristic parameters, time to SF, and fraction of inspired oxygen (FiO₂) prior to SF were all included in the multifactorial logistic regression model that explained LISA failure. Results: LISA failed in 114 of 500 infants (22.8%). The median time to SF was 2.1 h (IQR: 0.8-6.7), and the median FiO₂ prior to SF was 0.40 (IQR: 0.35-0.50). Factors significantly associated with LISA failure were FiO₂ prior to SF (OR 1.03, 95% CI 1.01-1.04) and gestational age (OR 0.82, 95 CI 0.75-0.89); both p <0.001. Time to SF was not an independent risk factor for therapy failure (p = 0.528) or the need for MV at any time during hospitalization (p = 0.933). Conclusions: The FiO₂ before SF, but not time to SF, influences the need for MV in infants with RDS. While our findings support the relevance of FiO₂ in SF prescription, better adherence to the recommended FiO₂ threshold for SF (0.30) is required in daily practice.

Introduction of less invasive surfactant administration (LISA), impact on diagnostic and therapeutic procedures in early life: a historical cohort study

Background

In preterm infants with Respiratory Distress Syndrome (RDS), Less Invasive Surfactant Administration (LISA) has been established to reduce the need of mechanical ventilation and might improve survival rates without bronchopulmonary dysplasia. The aim of this study was to investigate whether NICU care has changed after introduction of less invasive surfactant administration (LISA), with regard to diagnostic and therapeutic procedures in the first week of life.

Methods

Infants with gestational age < 32 weeks who received surfactant by LISA (June 2014 – December 2017, n = 169) were retrospectively compared to infants who received surfactant after intubation (January 2012 – May 2014, n = 155). Local protocols on indication for surfactant, early onset sepsis, blood transfusions and enteral feeding did not change between both study periods. Besides, as secondary outcome complications of prematurity were compared. Data was collected from electronic patient files and compared by univariate analysis through Students T-test, Mann Whitney-U test, Pearson Chi-Square test or Linear by Linear Association.

Results

All baseline characteristics of both groups were comparable. Compared to controls, LISA patients received a higher total surfactant dose (208 vs.160 mg/kg; p < 0.001), required redosing more frequently (32.5% vs. 21.3%; p = 0.023), but needed less mechanical ventilation (35.5% vs. 76.8%; p < 0.001). After LISA, infants underwent fewer X-rays (1.0 vs. 3.0, p < 0.001), blood gas examinations (3.0 vs. 5.0, p < 0.001), less inotropic drugs (9.5% vs. 18.1%; p = 0.024), blood transfusions (24.9% vs. 41.9%, p = 0.003) and had shorter duration of antibiotic therapy for suspected early onset sepsis (3.0 vs. 5.0 days, p < 0.001). Moreover, enteral feeding was advanced faster (120 vs. 100 mL/kg/d, p = 0.048) at day seven. There were no differences in complications of prematurity.

Conclusion

The introduction of LISA is associated with significantly fewer diagnostic and therapeutic procedures in the first week of life, which emphasizes the beneficial effects of LISA.

Implementation of less invasive surfactant administration in clinical practice-Experience of a mid-sized country

Objective

There are differences in the adoption rates of less invasive surfactant administration (LISA) worldwide. We aimed to describe and analyze the process of LISA introduction at the country level.

Methods

A standardized training program (33 courses covering >500 neonatologists) was followed by a cohort study. Data regarding consecutive LISA procedures were acquired over 12 months in 31 tertiary neonatal centers, using a dedicated on-line platform.

Results

Of 500 LISA procedures, 75% were performed by specialists and 25% by residents. The mean percentage share of LISA in all surfactant therapies was 24%, which represents a 6-fold increase compared to previous years. After 12 months, 76% of the procedures were rated “easy/very easy” vs 59% at baseline (p<0.05). Surfactant re-treatment rate was 15%. Twenty-three percent of infants required mechanical ventilation within 72 hours of life. Oxygen desaturation and surfactant reflux were the most frequent complications. Unlike previous reports describing exclusive use of nasal continuous positive airway pressure (nCPAP) during LISA, majority of procedures (63%) were carried out using nasal intermittent positive pressure ventilation (NIPPV) or Bilevel Positive Airway Pressure (BiPAP). Efficacy of LISA with NIPPV or BiPAP was not significantly different from that with nCPAP (22.4% vs 24.5% of cases requiring intubation). Ventilation was provided with nasal cannulas or nasal masks (90%) and rarely with “RAM” cannulas or nasopharyngeal tubes. Rigid catheters were preferred (88.4%); tracheal insertion was successful at first attempt in 87% of cases. Majority of infants (79%) received no premedication prior to the procedure and almost all were given caffeine citrate. Median time of instillation was 1.5 minutes.

Conclusions

The LISA procedure does not appear to be technically difficult to master. Training combining theory with practical exercises is an efficient implementation strategy. Variations in adoption rates indicate the need for additional, more personalized teachings in some centers.

Minimally Invasive Surfactant Therapy: An Analytical Report of Our Prospective Dubai Cohort

Introduction: Type 2 pneumocytes of the respiratory epithelium secrete the endogenous surfactant, a detergent-like substance that lines the alveolar sacs of the lungs. The surfactant facilitates the gas exchange process across the alveolar membrane by preventing the collapse of the alveoli and thereby maintaining their distended state. Respiratory distress syndrome of the premature neonates is characterized by quantitative and/or qualitative defects of endogenous surfactant metabolic pathways. The advent of exogenous surfactant therapy is rightly hailed as the major milestone in advancement of the care of the babies with surfactant-deficient lung disease. The administration of exogenous surfactant traditionally involves endotracheal intubation and mechanical ventilation. Minimally invasive surfactant therapy (MIST) is the technique of delivering surfactant without intubation whilst continuing the baby on noninvasive respiratory support. This author introduced MIST as the default way of administering surfactant in his neonatal units in Dubai and has to his credit the first published report on MIST from the United Arab Emirates in this journal in 2018. 

Objective: To analyze prospectively all our babies in Dubai who received surfactant by MIST.

Design: Prospective descriptive study of all babies receiving surfactant by MIST starting from January 2018.

Setting: Three tertiary care neonatal centers in Dubai.

Patients and methods: Thirteen babies (gestation 27-36 weeks and birth weight 0.95-2.81 kg) were treated with MIST on 15 occasions. Catheterization techniques were by infant feeding tube in 10 babies, LISA (less invasive surfactant administration) catheter in one baby, and 2.0 size endotracheal tube (ETT) with surfactant filled syringe directly attached to its hub two times each in two babies. Curosurf the porcine surfactant at 200 mg/kg was used on nine occasions and Survanta the bovine surfactant at 4 mL/kg on six occasions.

Main outcome measures: MIST success defined as the baby not needing intubation and ventilation within 72 hours post MIST. Outcome measures with respect to the different modalities of MIST procedure and surfactant preparations used in this prospective cohort.

Results: Only one of the 13 babies (7.7%) in this cohort needed escalation of support with mechanical ventilation and high frequency oscillation (HFO). MIST using semi-rigid catheters like the LISA catheter or the smallest size ETT was technically easier to perform. No differences were observed with regard to the surfactant preparation used. None had an abnormal neurosonogram and there were no instances of sepsis and necrotizing enterocolitis either. The baby that had an unsuccessful MIST had retinopathy of prematurity that was effectively treated with Laser post discharge from neonatal unit. All the babies in this cohort had age appropriate developmental milestones on subsequent follow up visits ranging from three months to two years.

Conclusions: MIST can be easily mastered and adapted in our neonatal units. MIST by any of the three variations of techniques as described in our cohort at FiO2 thresholds not exceeding 0.4 results in quicker resolution of the surfactant deficient lung disease, reduces the oxygen days in these babies and perhaps thereby insures intact survival of these babies.

[Risk factors for minimally invasive surfactant administration failure in preterm infants with respiratory distress syndrome]

OBJECTIVE

To identify risk factors for minimally invasive surfactant administration (MISA) failure in the treatment of preterm infants with respiratory distress syndrome (RDS) and the influence of MISA failure on neonatal outcome.

METHODS

A retrospective analysis was performed for the clinical data of 148 preterm infants with a gestational age of ≤32 weeks and a clinical diagnosis of RDS, who were admitted to the neonatal intensive care unit of eight tertiary hospitals in Beijing, Tianjin and Hebei Province from July 1, 2017 to December 31, 2018 and were treated with MISA (bovine pulmonary surfactant, PS). According to whether MISA failure (defined as the need for mechanical ventilation within 72 hours after MISA) was observed, the infants were divided into two groups: MISA failure group (n=16) and MISA success (n=132). A logistic regression analysis was used to investigate the risk factors for MISA failure and its influence on neonatal outcome.

RESULTS

The MISA failure rate was 10.8% (16/148). The logistic regression analysis showed that a high incidence rate of grade >II RDS before PS administration, low mean arterial pressure and high pulse pressure before administration, a low dose of initial PS administration, and long injection time and operation time were the risk factors for MISA failure (OR=5.983, 1.210, 1.183, 1.055, 1.036, and 1.058 respectively, P<0.05). After the control for the above risk factors, the logistic regression analysis showed that the MISA failure group had a significantly higher incidence rate of bronchopulmonary dysplasia (BPD) (OR=8.537, P<0.05).

CONCLUSIONS

A high grade of RDS, a low mean arterial pressure, and a high pulse pressure before administration are independent risk factors for MISA failure, and a low dose of initial PS administration, a long injection time, and a long operation time may increase the risk of MISA failure. MISA failure may increase the incidence rate of BPD in preterm infants.

Quality assessment and response to less invasive surfactant administration (LISA) without sedation

BACKGROUND

Although sedative premedication for endotracheal intubation is considered standard of care, less invasive surfactant administration (LISA) is often performed without sedative premedication. The aim of this study was to assess success rates, technical quality and vital parameters in LISA without sedative premedication.

METHODS

Prospective observational study in 86 neonates <32 weeks' gestation. LISA was performed according to a standardized protocol without use of sedative premedication. Outcome measures were success rates of LISA attempts, reasons for failure and quality of technical conditions. In 37 neonates, heart rate and oxygen saturation levels from 20 min before until 30 min after start of LISA were collected.

RESULTS

In 48% of LISAs the first attempt failed and in 34% quality of technical conditions was inadequate. The success rate was significantly correlated with quality of technical conditions and experience of the performer. Desaturations <80% occurred in 54% of patients while bradycardia <80/min did not occur.

CONCLUSION

This study shows a relatively low success rate of the first attempt of LISA, frequent inadequacy of technical quality and frequent oxygen desaturations. These effects may be improved by the use of sedative premedication.

Dose Effect of Poractant Alfa in Neonatal RDS: Analysis of Combined Data from Three Prospective Studies

Aim: To evaluate the effect of the initial dose of poractant alfa on clinical outcomes in neonatal respiratory distress syndrome (RDS) and to assess adherence to treatment guidelines recommending a dose of 200 mg/kg. Methods: Records of neonates who received poractant alfa with a less invasive technique (LISA) or with the INtubate-SURfactant-Extubate (INSURE) technique were retrieved from the aggregated datasets of three prospective RDS studies conducted between 2015 and 2019. The impact of poractant dose on neonatal outcomes was analyzed by multivariate logistic regression. The primary endpoint was the need for early (<72 h of life) mechanical ventilation (MV). Typical complications of prematurity and the need for surfactant retreatment were secondary endpoints. Deviation from the 200 mg/kg dose of surfactant was a measure of compliance with the treatment guidelines. As a complementary analysis, the rates of adverse outcomes were compared for infants receiving high (200 mg/kg ±10%) and low (100 mg/kg ±10%) doses of poractant. Results: Of 994 eligible infants, 574 received poractant alfa with LISA, and 420 received poractant with INSURE. A logistic regression model using data from all 994 infants showed that the surfactant dose had a significant effect on reducing the need for MV and retreatment; the respective odds ratios were 0.92 (95% CI: 0.90-0.95) and 0.93 (95% CI: 0.90-0.96) per 10-mg/kg dose increment of poractant alfa. This dose effect was observed across all gestational age ranges and in infants treated with LISA. In newborns treated with INSURE, the dose of surfactant only influenced the rates of retreatment (p = 0.036) but not MV (p = 0.170). No impact on other neonatal outcomes was observed. In the subset of infants who received high (N = 502) and low (N = 58) doses of poractant, the high-dose group had lower rates of MV (34 vs. 48%, p = 0.042) and lower rates of retreatment (11 vs. 21%, p = 0.045). Surfactant underdosage increased with gestational age and ranged from a minimum of -3 mg/kg in <26 weeks to a maximum of -23.5 mg/kg in >32 weeks. Conclusions: The initial dose of poractant alfa significantly impacts the need for invasive ventilation and retreatment. More mature newborns are at a greater risk of underdosing.

Early Predictors for INtubation-SURfactant-Extubation Failure in Preterm Infants with Neonatal Respiratory Distress Syndrome: A Systematic Review

The INtubation-SURfactant-Extubation (INSURE) procedure is a widely-used surfactant administration method to treat preterm infants with respiratory distress syndrome (RDS) but is not always successful. We conducted a systematic review to identify early predictive factors for failure of this procedure. A systematic literature search was performed until July 2018 in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials. Original studies comparing INSURE success with INSURE failure in preterm infants with RDS were included. A predefined data extraction form was used to retrieve data from articles, and methodological quality was assessed using the SIGN checklists. Fifteen studies out of 690 identified records met inclusion criteria. Methodological quality varied, only 8 studies performed multivariate analysis. We identified 20 different risk factors in total. Evidence for birth weight (BW) as a predictor for INSURE failure was inconsistent, but there was a significant association between decreasing gestational age (GA) and failure risk. RDS severity was assessed in multiple ways, using arterial blood gas values, imaging, and scoring systems. In conclusion, extremely low BW, low GA, and severe RDS appear to be risk factors for INSURE failure. However, evidence is inconsistent due to important methodological heterogeneity. Therefore, clinical applicability of these results is limited and implies the need for future large cohort studies on this subject.