Position the patient's head midline in a neutral position. If spinal injury is suspected, maintain head in a neutral in-line position. Stand to the patient's side with one hand on the tube and with the thumb and index finger of the other hand straddling the larynx. Remove nasopharyngeal airway and insert the tube into the nostril with flanged end of the tube along the floor of the nostril or facing the septum. As tube drops into the posterior pharynx listen for respiratory sounds.
Respiratory sounds are loudest when tube is proximal to the epiglottis.
Gently but swiftly advance the tube 3 to 5 cm during peak inspiration. Entrance into the larynx may initiate a slight cough, and most expired air should exit through the tube even though the cuff is uninflated. Breath condensation should intermittently fog the tube. Most upright patients tolerate intubation in that position. Voluntary tongue extrusion is helpful in cooperative patients.