Cricothyroidotomy, also known as cricothyrotomy, is an important emergency procedure that is used to obtain an airway when other, more routine methods (eg, laryngeal mask airway [LMA] and endotracheal intubation) are ineffective or contraindicated. Establishing an effective airway in the face of medical emergencies is a skill that healthcare providers must master to prevent patient morbidity or mortality.
Cricothyroidotomy is indicated upon failure to obtain an airway with traditional methods in the following situations:
- Trauma causing oral, pharyngeal, or nasal hemorrhage
- Facial muscle spasms or laryngospasm
- Uncontrollable emesis
- Upper airway stenosis or congenital deformities
- Clenched teeth
- Tumor, cancer, or another disease process or trauma causing mass effect
Airway obstruction indications include the following:
- Oropharyngeal edema (eg, anaphylaxis)
- Foreign body obstruction
The following are relative indications for cricothyroidotomy:
- Cervical spine immobilization secondary to injury
- Maxillofacial injuries
Nonemergent indications include the following:
- Prolonged intubation
- Maxillofacial, laryngeal, or oral surgery
The only absolute contraindication to surgical cricothyroidotomy is age, although the exact age at which a surgical cricothyrotomy can be safely performed is controversial and has not been well defined. Various sources list lower age limits ranging from 5 years to 12 years , and Pediatric Advanced Life Support (PALS) defines the pediatric airway as age 1-8 years.
The most conservative approach is to use 12 years as the cutoff age. In patients below this cutoff age, needle cricothyrotomy is indicated because infants and children younger than 12 years have a smaller cricothyroid membrane and a more funnel-shaped, rostral, and compliant larynx. A commercially available set has now been developed for minimally invasive cricothyroidotomy in infants (Quicktrach baby™). The set consists of a plastic cannula over a metal needle for direct placement in the trachea. So far, however, this device has not been evaluated for its intended use
A permanent tracheostomy should be placed within 24 hours. Needle cricothyrotomy can be used for approximately 40 minutes, after which time carbon dioxide accumulates; this can be particularly devastating in patients with head trauma. [thyroid gland is ensheathed by the visceral fascia, a division of the middle layer of deep cervical fascia, which attaches it firmly to the laryngoskeleton. The anterior suspensory ligament extends from the superior-medial aspect of each thyroid lobe to the cricoid and thyroid cartilage.
The posteromedial aspect of the gland is attached to the side of the cricoid cartilage, first and second tracheal ring, by the posterior suspensory ligament (ie, Berry ligament). This firm attachment of the gland to the laryngoskeleton is responsible for movement of the thyroid gland and related structures during swallowing.
For surgical cricothyroidotomy, materials needed include the following:
- Antiseptic preparation solution
- Sterile drape/gown/gloves
- 11 scalpel blade
- Syringe (10 mL)
- Bag-valve mask
- Trousseau dilator
- Tracheal hook
- Tracheostomy tube or endotracheal tube
On average, the adult cricothyroid membrane is 9 mm vertically and 30 mm horizontally. Endotracheal tubes with inner diameters of 6 mm and 8 mm have outer diameters of 8.2 mm and 10.9 mm, respectively. The No. 4 Shiley tracheostomy tube has a 5-mm inner diameter and a 9.4-mm outer diameter, whereas the No. 6 has a 6.4-mm inner diameter and a 10.8-mm outer diameter. Each tube comes with an outer cuffed cannula (cuffed tubes are recommended), an inner cannula, and an obturator.
For needle cricothyrotomy, materials needed include the following:
- Antiseptic solution
- Sterile materials
- Angiographic catheter (14 gauge or larger)
- Syringe (10 mL) filled with 5 mL of normal saline
- Pediatric endotracheal tube or modified intravenous (IV) extension set for transtracheal jet insufflations (3-mm endotracheal tube adapter with a Y-connector)
For percutaneous cricothyrotomy using the Seldinger technique, materials needed include a finder needle with a dilator and a guide wire (available in cricothyrotomy kits).
In an emergency situation, there is little time to provide anesthesia. Often, anesthesia is an unnecessary step that interferes with the acquisition of an emergency airway. If anesthesia is indicated, local anesthesia using 1% lidocaine without epinephrine is appropriate. The patient should be placed supine with the neck in the neutral position and medical personnel standing on the patient’s right side. C-spine immobilization should be applied if indicated.
Approach Considerations There are 3 main approaches to cricothyroidotomy: needle cricothyroidotomy, percutaneous cricothyroidotomy using the Seldinger technique, and surgical cricothyroidotomy
Needle cricothyroidotomy may be divided into the following steps:
- Position the patient, apply lidocaine (if indicated), and prepare a sterile field, including cleansing with antiseptic solution.
- Identify anatomic landmarks (see the images below).
- Palpate the thyroid cartilage (the first prominent landmark on the anterior neck), the cricoid cartilage (caudal to the thyroid cartilage), and the area between them, which is the cricothyroid space that contains the membrane. With the nondominant hand, stabilize the area using the first and third digits to either side of the thyroid cartilage, leaving the index finger to palpate the membrane.
- With the dominant hand, insert the angiographic catheter, attached to the syringe filled with normal saline, into the cricothyroid membrane, directing it caudally at a 45o angle.
- As the needle is advanced, apply negative pressure to the syringe. A distinct pop can be felt as the needle traverses the membrane and enters the trachea. In addition, air bubbles will appear in the fluid-filled syringe.
- Advance the catheter, and retract the needle.
- Attach the jet ventilation device, and ventilate at 40-50 lb per square inch or 15 L/min. If this device is unavailable, attach the barrel of a 3-mL syringe to the catheter, and place an endotracheal tube adapter. A bag valve mask (BVM) can then be attached to deliver oxygen for ventilation.
Percutaneous Cricothyroidotomy (Seldinger Technique)
Percutaneous cricothyroidotomy using the Seldinger technique may be divided into the following steps: Follow steps 1-4 from needle cricothyroidotomy (see above), substituting a finder needle attached to a syringe for the angiographic catheter. Remove the syringe from the needle, and advance the guide wire through the needle. Remove the needle once the guide wire is in place.
Use the scalpel to make a small stab incision in the skin close to the guide wire. Place the dilator into the airway catheter, and insert the 2 devices together over the wire. Remove both the dilator and the guide wire once the airway tube is secured in the trachea. Secure the tube in place with appropriate tape.
Surgical cricothyroidotomy (see the video below) may be divided into the following steps: See the list below: Follow steps 1-2 from needle cricothyroidotomy (see above). With the dominant hand, make a midline vertical incision, approximately 3 cm long and skin deep, over the cricothyroid membrane. A midline vertical incision may result in a small amount of venous bleeding but avoids the laterally located vasculature of the neck.
Palpate the cricothyroid membrane through the incision, using the index of the nondominant hand. Make a horizontal stab incision through the membrane. A distinct pop will be felt as the scalpel pierces the membrane and enters the trachea. An assistant should insert the tracheal hook at the superior end of the incision and retract the skin and membrane cephalad. Keep the scalpel in place until the tracheal hook is inserted. If the incision is lost, the location can be identified by means of air bubbles produced during exhalation.
If the patient is apneic, apply pressure to the anterior chest wall to simulate exhalation and thereby produce air bubbles. Dilate the incision vertically, using the Trousseau dilator with the nondominant hand. With the dominant hand, insert the tracheostomy tube between the 2 blades of the dilator, directing it initially to one side of the patient. Once the tube is through the membrane, rotate it 90o and insert caudally. Remove the obturator, and insert the inner cannula. Lock it into place. Inflate the balloon with 5-10 mL of air.
Attach the tube to a BVM and ventilate. Confirm placement through observation of chest rise, auscultation, and assessment of end-tidal CO2. Remove the tracheal hook, and secure the tube in place.
Rapid 4-step technique
Another approach to cricothyroidotomy is called the rapid 4-step technique (RFST). This technique involves a scalpel, a tracheal hook, and a tracheostomy tube and consists of the following 4 steps: palpation, stab incision, inferior traction, and tube insertion. Although the RFST is faster than the standard surgical technique, it has been shown to have a higher complication rate.