critical care medicine
Tracheal Intubation
Nasotracheal Intubation
If patients are spontaneously breathing, nasotracheal intubation can be used in certain emergency situations—eg, when patients have severe oral or cervical disorders (eg, injuries, edema, limitation of motion) that make laryngoscopy difficult. Nasotracheal intubation is absolutely contraindicated in patients with midface fractures or known or suspected basal skull fractures. Historically, nasal intubation was also used when muscle relaxants were unavailable or restricted (eg, out of scope of practice for prehospital personnel and some emergency departments) and in patients with decompensated Heart Failure (HF) and respiratory failure in upright position. However, availability of noninvasive means of ventilation (eg, When nasotracheal intubation is done, a vasoconstrictor (eg,phenylephrine) and topical anesthetic (eg,benzocaine,lidocaine) must be applied to the nasal mucosa and the larynx to prevent bleeding and to blunt protective reflexes. Some patients may also require IV sedatives, opioids, or dissociative drugs. After the nasal mucosa is prepared, a soft nasopharyngeal airway should be inserted to ensure adequate patency of the selected nasal passage and to serve as a conduit for topical drugs to the pharynx and larynx. The nasopharyngeal airway may be placed using a plain or anesthetic (eg,lidocaine) lubricant. The nasopharyngeal airway is removed after the pharyngeal mucosa has been sprayed. The nasotracheal tube is then inserted to about 14 cm depth (just above the laryngeal inlet in most adults); at this point, air movement should be audible. As the patient breathes in, opening the vocal cords, the tube is promptly passed into the trachea. A failed initial insertion attempt often prompts the patient to cough. Practitioners should anticipate this event, which allows a second opportunity to pass the tube through a wide open glottis. More flexible endotracheal tubes with a controllable tip improve likelihood of success. Some practitioners soften tubes by placing them in warm water to lessen the risk of bleeding and make insertion easier. A small commercially available whistle can also be attached to the proximal tube connector to accentuate the noise of air movement when the tube is in the correct position above the larynx and in the trachea. 