Ultrasound-assessed lung aeration, oxygenation and respiratory care in neonatal bile acid pneumonia: A nested case-control study.

AIM: Neonatal bile acid pneumonia (NBAP) occurs in neonates following obstetric cholestasis. We aimed to study the lung aeration and respiratory support of NBAP. METHODS: Nested, case/control study enrolling age-matched neonates with NBAP, respiratory distress syndrome (RDS) or transient tachypnoea (TTN). Lung aeration and oxygenation were assessed with lung ultrasound score, oxygenation index and SpO2 /FiO2 . RESULTS: Nineteen, 22 and 25 neonates with NBAP, RDS and TTN, respectively were studied (mean gestational age = 33 (2.2) weeks, 30 (45.5%) males). Upon admission, RDS patients had the worst lung ultrasound score (p = 0.022) and oxygenation index (p = 0.001), while NBAP and TTN neonates had similar values. At the worst time-point, NBAP and RDS patients showed similar oxygenation index (NBAP: 4.6 [2], RDS: 5.7 [3]) and SpO2 /FiO2 (NBAP: 3.1 [1.1], RDS: 2.7 [1]) which were worse than those of TTN patients (oxygenation index: p = 0.015, SpO2 /FiO2 : p = 0.001). RDS neonates needed the longest continuous positive airway pressure and highest mean airway pressure, but NBAP neonates needed invasive ventilation (26.3%, p = 0.01) and surfactant (31.6%, p = 0.003) more often than TTN patients who never needed these. CONCLUSION: NBAP was a mild disorder in the first hours of life but subsequently worsened and became similar to RDS.

Ultra-high frequency lung ultrasound in preterm neonates: a test validation study on interpretation agreement and reliability.

OBJECTIVE: To verify if increasing frequency, through the use of ultra-high frequency transducers, has an impact on lung ultrasound pattern recognition. DESIGN: Test validation study. SETTING: Tertiary academic referral neonatal intensive care unit. PATIENTS: Neonates admitted with respiratory distress signs. INTERVENTIONS: Lung ultrasound performed with four micro-linear probes (10, 15, 20 and 22 MHz), in random order. Anonymised images (600 dpi) were randomly included in a pictorial database: physicians with different lung ultrasound experience (beginners (n=7), competents (n=6), experts (n=5)) blindly assessed it. Conformity and reliability of interpretation were analysed using intraclass correlation coefficient (ICC), area under the curve (AUC) of the multi-class ROC analysis, correlation and multivariate linear regressions (adjusting for frequency, expertise and their interaction). OUTCOME MEASURES: A (0-3) score based on classical lung ultrasound semiology was given to each image as done in the clinical routine. RESULTS: ICC (0.902 (95% CI: 0.862 to 0.936), p<0.001) and AUC (0.948, p<0.001) on the whole pictorial database (48 images acquired on 12 neonates), and irrespective of the frequency and physicians' expertise, were excellent. Physicians detected more B-lines with increasing frequency: there was a positive correlation between score and frequency (ρ=0.117, p=0.001); multivariate analysis confirmed the score to be higher using 22 MHz-probes (ß=0.36 (0.02-0.7), p=0.041). CONCLUSION: Overall conformity and reliability of interpretations of lung ultrasound patterns were excellent. There were differences in the identification of the B-patterns and severe B-patterns as increasing probe frequency is associated with higher score given to these patterns.

Continuous Venovenous Hemofiltration Performed by Neonatologists With Cardio-Renal Pediatric Dialysis Emergency Machine to Treat Fluid Overload During Multiple Organ Dysfunction Syndrome: A Case Series.

OBJECTIVES: A new device is available for neonates needing extracorporeal renal replacement therapy. We reviewed the use of this device (in continuous venovenous hemofiltration [CVVH] mode) in term or preterm neonates affected by multiple organ dysfunction syndrome (MODS) with fluid overload. DESIGN: Case series. SETTING: Academic specialized referral neonatal ICU (NICU) with expertise on advanced life support and monitoring. PATIENTS: Neonates with MODS and fluid overload despite conventional treatments and receiving at least one CVVH session. INTERVENTION: CVVH with the Cardio-Renal Pediatric Dialysis Emergency Machine. MEASUREMENTS AND MAIN RESULTS: Ten (three preterm) neonates were treated using 18 consecutive CVVH sessions. All patients were in life-threatening conditions and successfully completed the CVVH treatments, which almost always lasted 24 hr/session, without major side effects. Three neonates survived and were successfully discharged from hospital with normal follow-up. CVVH reduced fluid overload (before versus after represented as a weight percentage: 23.5% [12-34%] vs 14.6% [8.2-24.1%]; p = 0.006) and lactate (before versus after: 4.6 [2.9-12.1] vs 2.9 mmol/L [2.3-5.5 mmol/L]; p = 0.001). CVVH also improved the Pa o2 to Fio2 (before vs after: 188 mm Hg [118-253 mm Hg] vs 240 mm Hg [161-309 mm Hg]; p = 0.003) and oxygenation index (before vs after: 5.9 [3.8-14.6] vs 4 [2.9-11]; p = 0.002). The average cost of CVVH in these patients was minor (≈3%) in comparison with the median total cost of NICU care per patient. CONCLUSIONS: We have provided CVVH to critically ill term and preterm neonates with MODS. CVVH improved fluid overload and oxygenation. The cost of CVVH was minimal compared with the overall cost of neonatal intensive care.

Respiratory and haemodynamic effects of 6h-pronation in neonates recovering from respiratory distress syndrome, or affected by acute respiratory distress syndrome or evolving bronchopulmonary dysplasia: a prospective, physiological, crossover, controlled cohort study.

Background: Pronation ameliorates oxygenation in adults with acute respiratory distress syndrome (ARDS); the effect in neonates with ARDS or other types of respiratory failure is unknown. We aimed to verify if pronation has similar respiratory and haemodynamic effects in three common types of neonatal respiratory failure. Methods: Prospective, physiologic, crossover, quasi-randomised, controlled cohort study performed in a tertiary academic neonatal intensive care unit. We enrolled neonates with: 1) recovering respiratory distress syndrome (RDS, mild restrictive pattern); 2) neonatal ARDS (NARDS, severe restrictive pattern); or 3) evolving bronchopulmonary dysplasia (BPD), that is chronic pulmonary insufficiency of prematurity (mixed restrictive/obstructive pattern). Neonates with other lung disorders, malformations or haemodynamic impairment were excluded. Patients were started prone or supine and then shifted to the alternate position for 6h; measurements were performed after 30' of "wash out" from the positioning and at the end of 6h period. Primary outcomes were respiratory (PtcCO2, modified ventilatory index, PtcO2/FiO2, SpO2/FiO2, oxygenation index, ultrasound-assessed lung aeration) and haemodynamic (perfusion index, heart rate, arterial pressure, cardiac output) parameters. Findings: Between May 1st, 2019, and May 31st, 2021, 161 participants were enrolled in this study, and included in the final analysis. Pronation improved gas exchange and lung aeration (p always <0.01) and these effects were overturned in the alternate position, except for lung aeration in NARDS where the improvement persisted. The effects were greater in patients recovering from RDS than in those with evolving BPD than in those with NARDS, in this order (p always <0.01). Pronation produced a net recruitment as lung ultrasound score decreased in patients shifted from supine (16.9 (standard deviation: 5.8)) to prone (14.1 (standard deviation: 3.3), p < 0.01) and this reduction correlated with oxygenation improvement. Haemodynamic parameters remained within normal ranges. Interpretation: 6h-pronation can be used to improve gas exchange and lung aeration in neonates with recovering RDS, evolving BPD or NARDS without relevant haemodynamic effects. Funding: None.

Evolution of Ultrasound-Assessed Lung Aeration and Gas Exchange in Respiratory Distress Syndrome and Transient Tachypnea of the Neonate.

OBJECTIVE: To use clinical, lung ultrasound, and gas exchange data to clarify the evolution of lung aeration and function in neonates with respiratory distress syndrome (RDS) and transient tachypnea of the neonate (TTN), the most common types of neonatal respiratory failure. STUDY DESIGN: In this prospective observational cohort study, lung aeration and function were measured with a semiquantitative lung ultrasound score (LUS) and transcutaneous blood gas measurement performed at 1 hour (time point 0), 6 hours (time point 1), 12 hours (time point 2), 24 hours (time point 3) and 72 hours (time point 4) of life. Endogenous surfactant was estimated using lamellar body count (LBC). LUS, oxygenation index (OI), oxygen saturation index (OSI), and transcutaneous pressure of carbon dioxide (PtcCO2) were the primary outcomes. All results were adjusted for gestational age. RESULTS: Sixty-nine neonates were enrolled in the RDS cohort, and 58 neonates were enrolled in the TTN cohort. LUS improved over time (within-subjects, P < .001) but was worse for the RDS cohort than for the TTN cohort at all time points (between-subjects, P < .001). Oxygenation improved over time (within-subjects, P = .011 for OI, P < .001 for OSI) but was worse for the RDS cohort than for the TTN cohort at all time points (between-subjects, P < .001 for OI and OSI). PtcCO2 improved over time (within-subjects, P < .001) and was similar in the RDS and TTN cohorts at all time points. Results were unchanged after adjustment for gestational age. LBC was associated with RDS (ß = -0.2 [95% CI, -0.004 to -0.0001]; P = .037) and LUS (ß = -3 [95% CI, -5.5 to -0.5]; P = .019). CONCLUSIONS: For the first 72 hours of life, the RDS cohort had worse lung aeration and oxygenation compared with the TTN cohort at all time points. CO2 clearance did not differ between the cohorts, whereas both lung aeration and function improved in the first 72 hours of life.

Ultrasound-assessed lung aeration correlates with respiratory system compliance in adults and neonates with acute hypoxemic restrictive respiratory failure: an observational prospective study.

BACKGROUND: Lung ultrasound allows lung aeration to be assessed through dedicated lung ultrasound scores (LUS). Despite LUS have been validated using several techniques, scanty data exist about the relationships between LUS and compliance of the respiratory system (Crs) in restrictive respiratory failure. Aim of this study was to investigate the relationship between LUS and Crs in neonates and adults affected by acute hypoxemic restrictive respiratory failure, as well as the effect of patients' age on this relationship. METHODS: Observational, cross-sectional, international, patho-physiology, bi-center study recruiting invasively ventilated, adults and neonates with acute respiratory distress syndrome (ARDS), neonatal ARDS (NARDS) or respiratory distress syndrome (RDS) due to primary surfactant deficiency. Subjects without lung disease (NLD) and ventilated for extra-pulmonary conditions were recruited as controls. LUS, Crs and resistances (Rrs) of the respiratory system were measured within 1 h from each other. RESULTS: Forty adults and fifty-six neonates were recruited. LUS was higher in ARDS, NARDS and RDS and lower in control subjects (overall p < 0.001), while Crs was lower in ARDS, NARDS and RDS and higher in control subjects (overall p < 0.001), without differences between adults and neonates. LUS and Crs were correlated in adults [r = - 0.86 (95% CI - 0.93; - 0.76), p < 0.001] and neonates [r = - 0.76 (95% CI - 0.85; - 0.62), p < 0.001]. Correlations remained significant among subgroups with different causes of respiratory failure; LUS and Rrs were not correlated. Multivariate analyses confirmed the association between LUS and Crs both in adults [B = - 2.8 (95% CI - 4.9; - 0.6), p = 0.012] and neonates [B = - 0.045 (95% CI - 0.07; - 0.02), p = 0.001]. CONCLUSIONS: Lung aeration and compliance of the respiratory system are significantly and inversely correlated irrespective of patients' age. A restrictive respiratory failure has the same ultrasound appearance and mechanical characteristics in adults and neonates.

Oscillation Transmission of Modern High-Frequency Neonatal Ventilators Under Different Lung Mechanics Conditions.

BACKGROUND: High-frequency oscillatory ventilation (HFOV) is widely used in neonatal critical care, and several modern ventilators using different technologies are available to provide HFOV. These devices have different technical characteristics that might interact with patient lung mechanics to influence the effectiveness of ventilation. To verify this, we studied the oscillation transmission of 5 neonatal oscillators in a lung model mimicking the mechanical patterns commonly observed in neonatal practice. METHODS: This was a benchtop, in vitro, physiological, pragmatic study using a model mimicking airways and lung of a 1-kg preterm neonate and the following patterns: normal (compliance: 1.0 mL/cm H2O, resistance: 50 cm H2O/L/s), restrictive (compliance: 0.3 mL/cm H2O, resistance: 50 cm H2O/L/s), and mixed mechanics (compliance: 0.3 mL/cm H2O, resistance: 250 cm H2O/L/s). Several permutations of HFOV parameters (variable mean airway pressure or amplitude or frequency protocols) were tested. Oscillations were measured with a dedicated pressure transducer validated for use during HFOV, and oscillatory pressure ratio (OPR) was calculated to estimate the oscillation transmission. RESULTS: Overall OPR (calculated on all experiments) was significantly different between ventilators and the mechanical patterns (both P < .001). Different ventilators and patterns accounted for 35.6% and 20.6% of the variation in oscillation transmission, respectively. Sub-analyses per changing amplitude or frequency protocols and multivariate regressions showed that VN500 (standardized ß coefficient [St.ß]: 0.548, P < .001) and Fabian HFO (St.ß: 0.421, P < .001; adjusted R2: 0.615) provided the best oscillation transmission. Fabian HFO also delivered oscillations with the lowest variability when increasing amplitude. CONCLUSIONS: In an experimental setting mimicking typical neonatal lung disorders, the oscillation transmission was more dependent on the ventilator model than on the mechanical lung conditions at equal HFOV parameters. Fabian HFO and VN500 provided better oscillation transmission overall, and when increasing amplitude, Fabian HFO delivered oscillations with the lowest variability.

Enhanced INSURE (ENSURE): an updated and standardised reference for surfactant administration.

There is no firm consensus about the optimal technique for the administration of exogenous surfactant in preterm neonates, and different techniques may be equally effective. The intubation-surfactant-extubation (INSURE) procedure has not been fully described, and important details, such as duration and mode of ventilation, remain unclear, leading to significant clinical practice variations and influencing its suitability and feasibility. Since the first INSURE description, our knowledge in respiratory care has largely progressed, but the technique has not been updated according to current evidence-based practice. Thus, our aim is to formally describe a modern way to perform INSURE, based on the current knowledge and technology, to increase its feasibility and patients' safety. We offer ENSURE (Enhanced INSURE) as an updated and standardised technique for surfactant administration, clarifying crucial issues of the original method by applying current state-of-the-art concepts of respiratory care. We performed a cross-sectional observational study enrolling 57 preterm neonates describing ENSURE feasibility and safety.   Conclusion: ENSURE can be used as a reference technique in clinical practice, teaching and research. What is Known: • There is no consensus about the optimal method for surfactant administration. INSURE technique has been originally described many years ago without considering modern principles of neonatal respiratory care and the available state-of-the-art technology. What is New: • We here describe a modern way to perform INSURE, based on the current knowledge and technology. We called it ENSURE (Enhanced INSURE) and clarified crucial points of the original technique, in light of the current knowledge. We verified feasibility and safety of ENSURE in a cross-sectional observational study enrolling 57 preterm neonates.

Nasal High-Frequency Ventilation.

Noninvasive high-frequency oscillatory (NHFOV) and percussive (NHFPV) ventilation represent 2 nonconventional techniques that may be useful in selected neonatal patients. We offer here a comprehensive review of physiology, mechanics, and biology for both techniques. As NHFOV is the technique with the wider experience, we also provided a meta-analysis of available clinical trials, suggested ventilatory parameters boundaries, and proposed a physiology-based clinical protocol to use NHFOV.

Effect of inspired gas temperature on lung mechanics and gas exchange in neonates in normothermia or therapeutic hypothermia.

BACKGROUND: Respiratory critical care guidelines suggest heating the air/oxygen mixture but do not recommend a specific temperature target. We aimed to clarify if the inspired gas temperature influences lung mechanics and gas exchange in intubated patients treated with whole body hypothermia (WBH) or normothermia (NT). METHODS: Prospective cohort study enrolling neonates ventilated for perinatal asphyxia resuscitation (no lung disease) or acute hypoxemic respiratory failure. Patients were divided between those ventilated in NT or WBH. Compliance (Cdyn), airway resistances (Raw), oxygenation index (OI), PaO2/FiO2, A-a gradient, a/A ratio, estimated alveolar dead space (VDalv), ventilatory index (VI) and CO2 production (VCO2) were registered at the study beginning (inspired gas at 37°C). Then, gas temperature was decreased (32 °C) and variables were recorded again after 1 and 3 h. Data were analysed with univariate and multivariate repeated measures-ANOVA. RESULTS: Cdyn, Raw, OI, PaO2/FiO2, A-a gradient, a/A ratio, VDalv, VI and VCO2 are similar between WBH and NT at any timepoint (between-subjects effect); these results do not change adjusting for the presence of respiratory failure. When this is considered in multivariate ANOVA (within-subjects effect), Cdyn (p = 0.016), Raw (p = 0.034) and VDalv (p < 0.001) were worse in patients with respiratory failure than in those without lung disease. CONCLUSIONS: Decreasing the gas temperature from 37 °C to 32 °C for 3 h does not change lung mechanics and gas exchange, neither in neonates with, nor in those without respiratory failure and in those treated in NT or WBH. These findings fill a knowledge gap regarding the effect of inspired gas temperature during WBH: they may inform future respiratory critical care guidelines.

Ultrasound-guided lung lavage for life-threatening bronchial obstruction due to meconium plug.

We present a case of life-threatening airway obstruction caused by meconium aspiration, a condition with significant neonatal mortality and morbidity. Lung ultrasound detected the obstruction and helped in the clinical management allowing to perform a quick and selective bronchoalveolar lavage with diluted surfactant.

Less invasive surfactant administration: a word of caution.

Surfactant is a cornerstone of neonatal critical care, and the presumed less (or minimally) invasive techniques for its administration have been proposed to reduce invasiveness of neonatal critical care interventions. These techniques are generally known as less invasive surfactant administration (LISA) and have quickly gained popularity in some neonatal intensive care units. Despite the increase in the use of LISA, we believe that the pathobiological background supporting its possible clinical benefits is unclear. Similarly, it is unclear whether there are any ignored drawbacks, as LISA has been tested in only a few trials and some physiopathological issues seem to have gone unnoticed. Active research is warranted to fill these knowledge gaps before LISA can be firmly recommended. In this Viewpoint, we provide an in-depth analysis of LISA techniques, based on physiological and pathobiological factors, followed by a critical appraisal of available clinical data, and highlight some possible future research directions.

Short- and long-term respiratory outcomes in neonates with ventilator-associated pneumonia.

BACKGROUND AND OBJECTIVE: Ventilator-associated pneumonia (VAP) is a common nosocomial infection in critical care settings and might have important long-term consequences in neonates. Our aim is to clarify the short- and long-term respiratory outcomes of neonates affected by VAP. METHODS: Prospective, population-based, cohort study with 12 months follow-up based on clinical examinations and diary-based respiratory morbidity score, conducted in an academic tertiary referral neonatal unit with dedicated follow-up program. RESULTS: A total of 199 inborn neonates consecutively ventilated for at least 48 hours were eligible for the study. One hundred fifty-one were finally enrolled and classified as "exposed" or "unexposed" to VAP, if they fulfilled (or not) VAP criteria once during their stay. Bronchopulmonary dysplasia (BPD) incidence was significantly higher in exposed (75%) than in unexposed babies (26.8%; relative risk [RR]: 2.8 [1.9-4.0]; Adj RR: 3.5 [1.002-12.7]; P = .049; number needed to harm = 2.07), although the composite BPD/mortality did not differ. Exposed patients showed longer intensive care unit stay (87 [43-116] vs 14 [8-52] days; St.ß = 0.24; P < .0001) and duration of ventilation (15 [10-25] vs 5 [4-8] days; St.ß = 0.29; P < .0001) than unexposed neonates. Exposed patients also showed less ventilator-free days (11 [5-17.7] vs 22 [14-24] days; St.ß = -0.15; P = .05) compared to unexposed. Respiratory infections, use of drugs, rehospitalization for respiratory reasons, home oxygen therapy, their composite outcome, and diary-based clinical respiratory morbidity score were similar between the cohorts. CONCLUSION: Neonatal VAP seems associated to higher incidence of BPD, longer ventilation, and intensive care stay but it does not affect long-term respiratory morbidity.

Life-Threatening Extreme Methemoglobinemia during Standard Dose Nitric Oxide Therapy.

We report the first case of life-threatening extreme neonatal-acquired methemoglobinemia that occurred during inhaled nitric oxide (iNO) at the standard 20 ppm dose in a neonate with early onset sepsis and suprasystemic pulmonary hypertension. Life-threatening methemoglobinemia has been efficaciously treated with methylene blue and ascorbic acid, while stopping iNO and starting iloprost and sildenafil. The patient was subjected to various tests (including gene sequencing and hemoglobin electrophoresis) and did not have any known genetic cause or predisposition for methemoglobinemia. Neuroimaging and the 2-year clinical follow-up were completely normal.

Mechanics of nasal mask-delivered HFOV in neonates: A physiologic study.

OBJECTIVES: To clarify if nasal mask influences noninvasive high-frequency oscillatory ventilation (NHFOV) mechanics to optimize the clinical use of nasal mask-delivered NHFOV. WORKING HYPOTHESIS: Nasal mask may affect the mechanical efficacy of NHFOV. METHODOLOGY: We designed a physiologic study composed of an in vitro phase aiming to investigate pressure transmission and volume delivery in a bench model of nasal mask-delivered NHFOV. In a second phase, we measured the leaks in vivo in a series of neonates receiving nasal mask-delivered NHFOV or other forms of noninvasive respiratory support with same nasal masks. RESULTS: In vitro pressure transmission is lower with nasal mask (pressure at the lung [Plung]: 2 [0.8]), than with the endotracheal tube (Plung 9.5 [1.5] cmH2 O; P = 0.007). Same applies for volume delivery (Vol: 0.6 [0.2] vs 1.8 [0.5] mL; P = 0.0001). Increasing ventilatory boundaries slowly affects pressure and volume delivery. Ventilating the model with maximal parameters (∆P = 55 cmH2 O; frequency = 8 Hz) we obtained a Vol 1.5 (0.2) mL. The nasal mask provides lower volume delivery and ventilation, compared with nasal prongs studied in previously published studies. Changing frequency allows a better performance than changing ∆P. In vivo leaks are approximately 30% and are similar during NHFOV or other forms of nasal mask-delivered noninvasive ventilation. CONCLUSIONS: Nasal mask-delivered NHFOV is feasible, but it may require more aggressive ventilatory parameters to increase volume delivery and ventilation. The use of the nasal mask is associated with some leaks, but this is independent from the type of noninvasive respiratory support applied.

Echography-Guided Surfactant Therapy to Improve Timeliness of Surfactant Replacement: A Quality Improvement Project.

OBJECTIVE: To improve time of surfactant administration with a surfactant replacement protocol based on semiquantitative lung ultrasound score (LUS) thresholds. STUDY DESIGN: Quality improvement (QI), prospective, before-after, pilot study. In a 6-month period surfactant replacement was based only on inspired oxygen fraction (FiO2) thresholds. In the second 6-month period, surfactant was given when either the FiO2 or LUS exceeded the limits. The main QI measures were the proportion of neonates receiving surfactant within the first 3 hours of life and maximal FiO2 reached before surfactant replacement. Secondary QI measures were the duration of respiratory support and ventilator-free days. Data were also collected for 1 year after the study to verify sustainability. RESULTS: Echography-guided Surfactant THERapy (ESTHER) increased the proportion of neonates receiving surfactant within the first 3 hours of life (71.4%-90%; P < .0001) and reduced the maximal FiO2 reached before surfactant replacement (0.33 [0.26-0.5]) vs 0.4 [0.4-0.55]; P = .005). The global need for surfactant did not significantly change. ESTHER also resulted in a significant decrease in duration of invasive ventilation and ventilator-free days. CONCLUSIONS: ESTHER improved the timeliness of surfactant administration and secondary QI indicators related to surfactant replacement.

Estimation of early life endogenous surfactant pool and CPAP failure in preterm neonates with RDS.

BACKGROUND: It is not known if the endogenous surfactant pool available early in life is associated with the RDS clinical course in preterm neonates treated with CPAP. We aim to clarify the clinical factors affecting surfactant pool in preterm neonates and study its association with CPAP failure. METHODS: Prospective, pragmatic, blind, cohort study. Gastric aspirates were obtained (within the first 6 h of life and before the first feeding) from 125 preterm neonates with RDS. Surfactant pool was measured by postnatal automated lamellar body count based on impedancemetry, without any pre-analytical treatment. A formal respiratory care protocol based on European guidelines was applied. Clinical data and perinatal risk factors influencing RDS severity or lamellar body count were real-time recorded. Investigators performing lamellar body count were blind to the clinical data and LBC was not used in clinical practice. RESULTS: Multivariate analysis showed gestational age to be the only factor significantly associated with lamellar body count (standardized ß:0.233;p = 0.023). Lamellar body count was significantly higher in neonates with CPAP success (43.500 [23.750-93.750]bodies/µL), than in those failing CPAP (20.500 [12.250-49.750] bodies/µL;p = 0.0003).LBC had a moderate reliability to detect CPAP failure (AUC: 0.703 (0.615-0.781);p < 0.0001; best cut-off: ≤30,000 bodies/µL). Upon adjustment for possible confounders, neither lamellar body count, nor its interaction factor with gestational age resulted associated with CPAP failure. CONCLUSIONS: Early postnatal lamellar body count on gastric aspirates in CPAP-treated preterm neonates with RDS is significantly influenced only by gestational age. Lamellar bodies are not associated with CPAP failure. Thus, the endogenous surfactant pool available early in life only has a moderate reliability to predict CPAP failure.