Integrated echocardiography and lung ultrasound assessment of lung recruitment in preterm infants using high frequency ventilation: A prospective, single-arm, protocol-driven cohort study.

BackgroundLung recruitment maneuvers (LRM) during high-frequency oscillatory ventilation (HFOV) lack bedside standardized monitoring.AimTo evaluate the efficacy and safety of FiO2-guided LRM in preterm infants with moderate-to-severe respiratory-distress syndrome (RDS) using integrated functional echocardiography (FE) and lung ultrasound (LUS). Also, we hypothesized that a standardized LUS score can accurately guide successful recruitment.MethodsThis a prospective, single-arm, protocol-driven cohort study that was conducted at a tertiary NICU (Alexandria University), and 70 preterm infants (GA 32-37 weeks) requiring HFOV within 24 h of life were included. Integrated LUS and FE were performed at three phases: pre-initiation, maintenance pressure (opening), and pre-weaning. Lung aeration was quantified using a standardized 12-zone LUS protocol (0-3 points per zone) based on international consensus. Hemodynamics were assessed via tricuspid regurgitation (TR) gradient, superior vena cava (SVC) flow, and right ventricular myocardial performance index (RV-MPI).ResultsLRM led to significant improvements in oxygenation and lung aeration. Mean LUS scores decreased significantly from 23.13 ± 1.33 (pre-initiation) to 19.94 ± 1.67 (maintenance) and 3.70 ± 2.49 (pre-weaning) (p < 0.001). FE demonstrated a significant reduction in TR gradient (p < 0.001), while SVC flow and RV-MPI remained stable, indicating preserved myocardial function. Pre-weaning LUS scores were significantly associated with weaning success from HFOV.ConclusionsFiO2-guided LRM is effective and safe in late-preterm infants with RDS. Integrated bedside imaging confirms that recruitment improves lung aeration without compromising hemodynamics. A standardized LUS score is a reliable tool for identifying optimal lung opening and guiding the weaning process.