Airway Skills 16:
Transtracheal Needle Ventilation
Transtracheal needle ventilation (TTNV) may be performed on awake patients, but the jet of oxygen in the trachea will stimulate coughing. TTNV may require patient paralysis or injection of 2 to 4 mL of 2% to 4% lidocaine into the trachea.
- Palpate the neck identifying the tracheal rings, the cricoid cartilage, the larynx, and the hyoid bone. The cricothyroid membrane occupies a small finger nail space between the cricoid cartilage and the larynx. When this is easily felt, a skin incision is not needed. However, if in doubt, do not hesitate to make a generous incision. The cricoid cartilage hinges to the thyroid cartilage, so if the neck is extended, the space becomes larger.
- Attach a small syringe to a Cook Co. 8.0 French transtracheal needle (needle/catheter). This is critical: the cricothyroid membrane is ligamentous and offers significant resistance to penetration. Use the syringe as a handle to puncture the membrane. If the needle is held at the hub instead, the cannula gets pushed ahead of the needle and prevents penetration. Insert the needle perpendicular to the skin to accurately penetrate the cricothyroid membrane. If the needle goes through cartilage, the rest of the procedure will be difficult. Intermittently aspirate for air. When air or mucous is aspirated without resistance, the needle is in correct position. Do not advance the needle further. Gently angle the needle so that it points down the trachea. Now advance it a short distance down the trachea while casting off the catheter as if starting an IV. Insert the catheter to its hub.
- Aspirate with the syringe again. You should get a free flow of air or secretions. If not, pull back the catheter slightly and try aspiration again. When no resistance to aspiration results, you are ready to start ventilations.
Moonlighter’s Device
- The ventilating device is called the moonlighter’s device. (See previous page.) The moonlighter’s device is made by cutting off the tip of an 18 French tracheal suction catheter and attaching a male Luer connector from blood pressure cuff tubing. The device is then connected to an oxygen flow meter (50 psi) with standard oxygen tubing. Ventilate by intermittently covering the suction port with your thumb. Set the flow meter for 15 L/min for adults and (PEDS) about 10 L/min for children. A newborn is well ventilated at 5 L/min. Watch for rise and fall of the chest as when using a bag-valve-mask. If exhalation does not occur, do not continue.
- Do not let go of the catheter. Whoever is ventilating must hold the catheter at all times. Ventilate as if using a BVM, watching the rise and fall of the chest. Leave time for exhalation to occur. Expiration must be at least twice as long as inspiration: recite breathe—exhale, exhale to achieve the correct rhythm. Secretions will be blown out of the trachea and mouth, so protect yourself appropriately. Place an oral airway in the mouth to aid in exhalation.
Complications include barotraumas to the bronchioles and pneumothorax. Oxygen can dissect around the catheter in the neck and dissect down into the mediastinum. Sometimes a thin layer of pneumomediastinum that will clear spontaneously may be seen on chest x-ray. The time limiting factor is the drying out of mucosa caused by the unhumidified oxygen. TTNV ventilation may be safely performed for at least 30 minutes and probably longer. Normal blood gases can be maintained.
TTNV is a useful temporizing method until a definitive airway can be established. TTNV may make orotracheal intubation possible in cases in which the glottis could not be visualized, as in acute epiglottitis.
References
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Jorden RC. Percutaneous transtracheal ventilation. Emerg Med Clin North Amer. 1988;6:745-752.
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Patel RG. Percutaneous transtracheal jet ventilation: a safe, quick, and temporary way to provide oxygenation and ventilation when conventional methods are unsuccessful. Chest. 1999;116:1689-1694.