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.
Subject(s)
Epiglottis/anatomy & histology , Nasopharynx/anatomy & histology , Vocal Cords/anatomy & histology , Airway Obstruction/therapy , Child , Child, Preschool , Epiglottis/diagnostic imaging , Female , Humans , Imaging, Three-Dimensional , Infant , Infant, Newborn , Intubation, Intratracheal/methods , Magnetic Resonance Imaging , Male , Nasopharynx/diagnostic imaging , Vocal Cords/diagnostic imagingABSTRACT
Significant advances have been made over the last decade to improve the performance, efficiency, and contrast of high peak and average power laser systems, driven by their use in a wide variety of fields, from the industrial to the scientific. As the contrast of the lasers has improved, interactions with contrasts of 1012 are now routinely undertaken. At such high contrasts, there is negligible preplasma formation and the ionized surface layer created by subpicosecond-duration pulses typically forms a highly reflective "plasma mirror" capable of reflecting between 70% and 90% of the incident energy. Although such interactions are of significant interest for applications such as harmonic source production and to enable the underlying physics to be studied, their low absorption can limit their usefulness for applications such as space debris removal.
