One of the most invasive airway procedures that can be performed by a paramedic is a surgical cricothyrotomy. Although infrequent, this procedure could mean the difference between life and death for a patient when there are no other means of securing their airway. With that being said, surgical cricothyrotomy is only to be used when other methods for ventilating a patient are not possible, such as endotracheal intubation or the use of a BVM. We must also add, ALWAYS FOLLOW YOUR LOCAL PROTOCOLS AND PROCEDURES!!
In most cases, cricothyrotomy is not needed, as prior attempts at establishing an airway are usually successful. The incidence level for cricothyrotomy is only about 1%. In a study conducted by air-transport providers in a large multi-state system, over the course of 2 years, 4,871 patients required airway management. Of which, only 35 (.7%) required surgical cricothyrotomy.
There are several methods for performing a cricothyrotomy. The two most common ways are surgical cricothyrotomy and needle cricothyrotomy. In order to perform either of these methods, it's vital to know the key anatomy of the anterior neck. The trachea is the rigid tube-like structure that gives access to the lungs and is what the breathing tube must be inserted into in order to ventilate the patient. Attached to the trachea, is the thyroid cartilage, also known as the "Adam’s Apple," which can be easily palpated as you glide your fingers down the patient's neck. Directly inferior to the thyroid cartilage is another slightly smaller protuberance known as the cricoid cartilage. In between these two is a small gap, which is the cricothyroid membrane. This is the place in which the tube will enter the trachea. There is also a high concentration of blood vessels in this region, which is why profuse bleeding is common during the initial incision of the skin.
Indications and Contraindications
Patients need a definitive airway whenever they cannot protect their own airway or when they cannot effectively ventilate. By definition, a definitive airway is one that enters the trachea and prevents aspiration of gastric contents.
Cricothyrotomy is not an initial means for establishing an airway. Due to the invasiveness of this procedure, it should only be attempted after all other means of securing an airway has been tried or considered. This means that you should first attempt to ventilate with a BVM and consider performing intubation before attempting a surgical airway. If you have determined that cricothyrotomy is the only possible means for establishing an airway, it is reasonable to have another provider attempting to ventilate while you are preparing your equipment.
Instances that may be difficult or impossible to ventilate by standard means and require surgical cricothyrotomy include:
- Foreign body obstructions of the upper airway that cannot be removed
- Swelling of the airway from epiglottitis, anaphylaxis or airway burns
- Massive maxillofacial trauma with profuse bleeding
- Inability to open the patient's mouth
The biggest contraindication for cricothyrotomy is the ability to secure the airway by a less invasive means as already mentioned. Other contraindications include not knowing the anatomy of the cricothyroid membrane or the proper procedure, trauma to the cricothyroid site, or children. The exact age at which surgical cricothyrotomy is contraindicated is not agreed upon. Some sources say younger than 8 years old, and some say younger than 12. Regardless, children with smaller, softer airway anatomy should receive needle cricothyrotomy as opposed to an incision of the cricothyroid membrane. This is because of an increased likelihood of cutting through the other side of the trachea or causing further damage. In any situation in which cricothyrotomy is contraindicated, the patient needs to be immediately transported to the nearest facility so that a tracheostomy can be performed by a doctor.
Once you have determined that you are going to proceed with cricothyrotomy, it is important to do so quickly, but effectively. Start by making sure that all your equipment is already prepared or being prepared by your partner while you prepare the site. Place the patient's neck in the neutral mid-line position. If no trauma is suspected, it is helpful the slightly extend the patients neck to hold the trachea in position. Stabilize the skin and the trachea with your non-dominant hand using your thumb and middle finger, allowing for your index finger to palpate the cricothyroid membrane as shown in figure 2. Clean the site as you would an IV site. For a surgical cricothyrotomy, use a scalpel and make a vertical incision over the cricothyroid membrane about 1-2 cm long and puncture the membrane. Make a 1 cm horizontal cut and spread the incision apart. Once the trachea is exposed, insert a 6.0 cuffed endotracheal tube. Inflate the cuff, attach the BVM and have your partner ventilate while you listen for breath sounds to ensure proper placement. Secure the tube with tape or a commercial device. End-tidal CO2 should also be attached to the tube to ensure adequate ventilation.
For needle cricothyrotomy, attach a 14 or 16 gauge IV catheter needle to a 10 mL syringe with about 3-5 mL of saline or water. With the syringe attached to the needle, insert into the cricothyroid membrane at a 45-degree angle towards the feet. While inserting, aspirate until you see bubbles in the syringe and then stop advancing the needle. Remove the needle, keeping the catheter in place. Attach the adapter from a 3.5-mm ET tube to the catheter so that a BVM can be attached. Ensure proper placement and adequate ventilation and secure the site using gauze and tape.
Cricothyrotomy is a high-risk/low-frequency procedure that when used properly, will save someone's life. Despite its low-frequency use, it is important to know and practice this systematic approach so that if the time does come, you are prepared and able to establish someone's airway when all else fails.