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

Abstract

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 β: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.

Personalized Medicine for the Management of RDS in Preterm Neonates

“…Unfortunately, LBC in gastric aspirate samples obtained in the first hours of life is not accurate enough to reliably predict CPAP failure due to surfactant need (AUC: 0.703, 95% CI: 0.696-0.710). It is also unsuitable, as the assay could not be performed in approximately 35% of samples due to viscosity or blood contamination [66]. LBC has also been investigated in a randomized clinical trial to guide surfactant replacement: it was unfeasible in 23% of patients for these technical problems and failed to improve the primary outcome (i.e., need for invasive ventilation or mortality) [67].…”

“…LUS data are those derived from the meta-analyses of all diagnostic accuracy studies[37][38][39][40][41][42] on this technique (see Fig.2). Data on chest X-rays, LBC, SAT, and SMT are extracted from Perri et al[39], Raschetti et al[66], Autilio et al[76], and Bhatia et al[80], respectively. Squares are proportional to the weight of populations used to study each technique (LUS: n = 443; chest Xrays: n = 56; LBC: n = 125; SAT: n = 56; and SMT: n = 68).…”

Early surfactant replacement guided by lung ultrasound in preterm newborns with RDS: the ULTRASURF randomised controlled trial

“…In recent guidelines, early therapy with surfactant is suggested in patients requiring nCPAP of at least 6 cmH 2 0 and an FiO 2 over 0.3 [ 2 ]. Certainly, this cut-off can be considered arbitrary, given that the current evidence is based on observational studies that considered FiO 2 requirements greater than 0.3 as a predictor of respiratory failure [ 3 ] and may not accurately reflect the patient’s oxygenation [ 4 ]. Therefore, it is challenging for neonatologists to identify the newborns who will benefit from early surfactant treatment (within the first 3 h of life), which is known to decrease pneumothorax and bronchopulmonary dysplasia and to improve survival rates [ 3 ].…”

Non-invasive Respiratory Support of the Premature Neonate: From Physics to Bench to Practice

“…These findings were recently corroborated in humans by a study conducted by Raschetti et al In prospectively followed infants, gastric aspirates were assessed for lamellar bodies; a correlate of the endogenous surfactant pool. They confirmed the positive effect prenatal corticosteroids have on enlarging the endogenous surfactant pool, and that a larger pool was moderately associated with CPAP success (117).…”