Oropharyngeal and Nasopharyngeal Airways

Oropharyngeal Airway

• Used to relieve upper airway obstruction if airway maneuvers fail to establish an airway.
• Can be used as a bite block in intubated patients.
• Use on sedated or unconscious patients.
• Insert using scissors (crosses fingers) technique.
• Remove if the patient gags or retches.
• Exercise body fluid precaution (saliva).
• Size selection includes: center of mouth to angle of jaw, corner of mouth to earlobe, and central incisors to angle of jaw.
• A too large airway pushes the epiglottis against the larynx, leading to airway obstruction.
• A too small airway may not clear the tongue, leading to airway obstruction by the tongue.

Nasopharyngeal Airway

• Also called nasal trumpet or nasal horn
• Facilitates ventilation and removal of secretions by nasotracheal suctioning.
• Inspect nares for obstruction and use a local anesthetic spray and water-soluble lubricant on airway.
• Insert parallel to the nasal floor with the distal end 1 cm from epiglottis.
• Size 6 is for adult female, Size 7 for adult male.
• Too short and it cannot separate soft palate from posterior wall of pharynx.
• Too long and it may enter larynx, causing laryngeal reflexes or enter the space between epiglottis and vallecula, leading to potential obstruction.

Laryngeal Mask Airway (LMA)

• Resembles a short ET tube with a small cushioned oblong-shaped mask on the distal end.
• Provides a seal over the larynx with standard cuff pressure of 60 cm H₂O.
• Indicated during CPR in profoundly unconscious patients without glossopharyngeal and laryngeal reflexes.
• Indicated when unable to perform endotracheal intubation.
• Contraindications include: does not protect airway from aspiration, should not be used in patients who have not fasted or with hiatal hernia, are not profoundly unconscious, have severe oropharyngeal trauma, require emergency resuscitation drug instilled directly into airway (e.g., epinephrine)
• A large LMA with less air in cuff gives a better seal
• Place profoundly unconscious patient in supine position, open mouth by depressing chin, and fully or partially deflate cuff.
• Keep mask opening facing away from operator
• Insert blindly through the mouth and along the hard palate, then to the posterior pharynx.
• Use fingers to guide for the curved turn around toward the trachea and larvnx.
• Removal is safe when patient is anesthetized or awake.
• Unstable airway may cause misplacement of mask and gastric insufflation.
• Cannot withstand high airway pressure (20 cm H₂O, up to 30 cm H2O with LMA-ProSeal).
• The optimal duration of use is less than 2 hours (up to 8 hours for experienced users).
• Excessive cuff pressure (more than 60 cm H2O) may lead to malposition.
• Does not protect lower airway from aspiration.
• Requires steam autoclave for reusable LMA (seldomly used)

Esophageal-Tracheal Combitube (ETC)

• The ETC is also called pharyngeal tracheal lumen airway and esophageal-tracheal airway.
• Blind intubation technique
• ETC may be inserted into the esophagus or trachea
• Ventilation is provided via Lumen 1 when ETC is in the esophagus.
• Ventilation is provided via Lumen 2 when ETC is in the trachea.
• When tube is in the esophagus, a small distal cuff (15 mL) seals off the esophagus
• When tube is in the trachea, a large proximal cuff (100 mL) seals off trachea
• Complications include: hemodynamic stress, cuff leaks, and other air leaks due to esophageal laceration (subcutaneous emphysema, pneumomediastinum, pneumoperitoneum).

Double-Lumen Endobronchial Tube (DLT)

• Also called double-lumen tracheobronchial tube.
• Indications include: Lung isolation (prevent lung-to-lung spillage of blood pus), surgical procedure on nonventilated lung, and bronchopleural or bronchocutaneous fistulas.
• Composed of 2 lumens, 2 cuffs, and 2 pilot balloons.
• Left-sided DLT is more commonly used.
• Right-sided DLT may cause RUL atelectasis if bronchial cuff passes the RUL bronchus.
  • (RUL bronchus is only about 2 cm distal from carina in adults)
• Patient is anesthetized and paralyzed to insert. Can be inserted under direct laryngoscopy.
• When tracheal cuff passes the vocal cords, the tube is about 6 cm (5+ in) from final position
• Inflate bronchial cuff and ventilate both lungs via the bronchial tube, then advance DLT to bronchus and note endpoint signs. These include: Resistance to advancement, unilateral ventilation, and reduction in compliance (increase in PIP).
• Deflate bronchial cuff and advance DLT another 2.5 to 3 cm (bronchial cuff length + 1 cm)
• Risk factors: Direct trauma, cuff overinflation, and preexisting airway pathology.