Quantitative Comparison of Airflow Through Neonatal Laryngeal Mask Airways and Endotracheal Tubes: A Benchtop and Mannequin Study
Andrew Faniku, Anjali AaluriBackground
Airway device resistance may influence airflow during pressure-controlled neonatal ventilation. Poiseuille’s law predicts lower resistance with wider and shorter lumens, but direct comparative airflow data for neonatal laryngeal mask airways (LMAs) and endotracheal tubes (ETTs) remain limited.
Methods
This benchtop/mannequin experimental study evaluated airflow through six empirically tested neonatal airway devices: LMA sizes 1.5 and 1.0, and ETT sizes 3.5, 3.0, 2.5, and 2.0 mm. A Neo-Tee infant T-piece resuscitator was connected to compressed air at 10 L/min and calibrated to deliver a peak inspiratory pressure of 20 cm H 2 O with PEEP of 5 cm H 2 O. Peak expiratory flow (PEF) and forced expiratory volume in 1 second (FEV₁) were measured using manual and digital flowmeters under free‑flow (bench) and mannequin‑lung conditions.
Results
In both bench and mannequin configurations, LMAs produced higher measured PEF and FEV
1
than ETTs, with measured flow decreasing as ETT diameter narrowed. During mannequin testing, LMAs measured higher airflow despite significant air leakage. LMA size 1 demonstrated substantially greater mean airflow (≈340 L/min) compared with ETT 3.5 (≈146.5 L/min). Exploratory ANOVA showed significant device-level differences for measured outcomes (
Conclusion
Under standardized bench and mannequin conditions, LMAs generated higher measured airflow than ETTs. These findings should be interpreted as experimental data on device airflow resistance and measured flow, rather than as evidence of superior neonatal ventilation. Translation to clinical practice, particularly in preterm neonates, requires further clinical and simulation studies that measure tidal volume, minute ventilation, leaks, and neonatal outcomes.