Airway Skills 13:
Cricothyrotomy
Some commercial cricothyrotomy devices available on the market are promoted as safe and easy to use. Unfortunately, none have been adequately tested by non-surgeons in clinical emergencies. The procedure described here has been performed numerous times in the CALS Benchmark Lab and has worked well.
- If you are right handed, stand on the patient's left side. Palpate the neck, identifying the tracheal rings, the cricoid cartilage, the larynx, and the hyoid bone. Grasp the trachea and larynx between the middle finger and thumb of your left hand.
- Make a 2-inch midline incision over the proximal trachea and the larynx using a #10 scalpel. Carry this incision down to the strap muscles. The wound will gape open when you have incised through the subcutaneous tissues, indicating that the incision is deep enough. You do not have to visualize the strap muscles or the airway structures. A midline incision results in less bleeding than a transverse incision. It may also be extended if needed.
- Insert the index finger of your left
hand into the wound. You will be able to easily palpate the larynx and
the cricoid cartilage. Insert a large tracheal hook (Ruiz trach hook,
Sklar Instruments) through the cricothyroid membrane that lies between
the larynx and the cricoid cartilage to lift either the larynx or the
cricoid cartilage and provide traction. It is easiest to place the hook
from the side.
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- Hold the hook toward the chin if the anatomy is relatively normal, pulling up the cricoid cartilage and trachea to a superficial position. You may ask an assistant to do this for you. Otherwise, if the anatomy is difficult so that the chin and/or beard are in the way, hold the hook toward the sternum, lifting up the cricoid cartilage. Take care not to fracture the cricoid cartilage. You can have an assistant do this for you. This technique is performed by feel. Even if there is bleeding, the membrane is easily felt. In this example, the hook is pulled up over the chin. If there is not enough room, pull it up over the sternum.
- Position the #10 scalpel transversely and hold it against the hook. Now stab straight back into the trachea through the cricothyroid membrane. The cricothyroid membrane is actually ligamentous, so it can offer some amount of resistance. You will feel a distinct give when the trachea is entered. Twist the scalpel so as to enlarge the hole. Because you have placed the hook and you are applying traction, the trachea will not move, even if the patient gasps. The knife is inserted next to the hook. If the hook has been pulled over the sternum, the knife would be on the other side of the hook.
- Insert an ET tube introducer (ETI or bougie) alongside the scalpel and through the incision you have made in the membrane; feel it move easily down the trachea over the tracheal rings. The ETI prevents false passage of the ET tube, a common error that easily occurs if an ETI is not used as a guide.
- Make sure the cuff of the 6.0 ET tube is fully deflated. Place it on the ETI and advance it into the trachea, inflate the cuff, and test its position with an esophageal intubation detector (EID). Ventilate. If all goes well, remove the hook.
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- Hold the ET tube until it is secured in place using a length of twill tape as shown in Vol II—Air Skills 1 Aids to Intubation, Securing an ET Tube. Apply sterile gauze around the ET tube, but do not pack it tightly. This is because if the patient coughs and air is forced around the cuff of the ET tube, the patient's neck will balloon out if the air cannot escape.
Sterile technique is used for this procedure except under dire circumstances. Local anesthesia with subcutaneous lidocaine is used in aware patients. Inject 2 to 4 mL of 2% to 4% lidocaine into the trachea prior to inserting the scalpel.
PEDS: Cricothyrotomy in children under about 8 years old may be difficult because of the tight cricoid ring and the small size of the cricothyroid membrane in small children. See Vol II—Air Skills 15 Tracheotomy in Infants and Vol II—Air Skills 16 Transtracheal Needle Ventilation that describe alternatives. Cricothyrotomy may be performed under the most dire circumstances in adults and (PEDS) older children. Trauma to the larynx is a contraindication.
Tools used in cricothyrotomy and tracheotomy