The nasopharyngeal airway: Estimation of the nares-to-mandible and nares-to-tragus distance in young children to assess current clinical practice

Abstract

Background: Nasopharygeal airways are used in urgent situations to alleviate airway obstruction. Guidelines for measuring the length of the NPA differ between national and international guidelines, and the evidence base for these measurements is lacking. The purpose of this study was to measure the nares-epiglottis and nares-vocal cord distances in young children (neonates to 12 years) on 3D reconstructed Magnetic Resonance Imaging (MRI) brain volume scans, and to examine the relationship of these distances with the nares-tragus and nares-mandible distances.

Method: One-hundred and seventy-six scans were reviewed. All patients had undergone MRI 3D brain volume imaging. The anatomical landmarks were identified and the nares-tragus, nares-mandible distances measured and compared to nares-epiglottis and nares-vocal cord distance using Osirix.

Results: The nares-epiglottis and nares-vocal cords distances significantly correlated (p-value <0.05). The nares-tragus distance showed strong correlation with the nares-epiglottis and nares-vocal cord distance compared to the nares-mandible distance (p-value <0.05).

Conclusion: In conclusion, the length of a nasopharyngeal airway in children under the age of twelve years can be predicted using the nares-tragus external anatomical distance minus 10 mm.

Keywords: Airway; Airway management; Airway obstruction; Child; Resuscitation.