- Cricothyroidotomy is a surgical airway through the cricothyroid membrane (below the vocal cords) that allows ventilation of the trachea bypasses the oropharynx upper airway.
- The airway can be obtained quickly in emergencies “cannot intubate, cannot ventilate” situations. It can be performed by a surgeon, anaesthetist, intensivist, or emergency physician.
- Techniques:
- Surgical
- Seldinger
- Needle (cannula)
- Indications
- Cannot intubate, cannot ventilate
- Airway obstruction: foreign body, angioedema
- Massive facial or nasal trauma
- Cervical spine instability causing an inability to adequately ventilate
- Fractured larynx (often from a hanging injury)
- Chemical inhalation injury
- Contraindications
- Inability to indentify lmarks
- Underlying abnormality, such as a tumor
- Tracheal transection
- Due to risk of subglottic stenosis, a needle cricothyroidotomy is preferred in pediatric patients.
- Advantages of cricothyroidotomy over tracheotomy
- Cricothyroid membrane is more superficial easier to access than tracheal rings
- Cartilage incision is not necessary
- Less vascular
- Can be performed more rapidly; experienced personnel can perform the procedure within 30 seconds
- Disadvantage
- Not a permanent airway must be converted to a tracheotomy within 24 hours in the operating room due to the risk of developing subglottic stenosis
The cricothyroid membrane lies between the thyroid cartilage superiorly the cricoid cartilage inferiorly. Identify the thyroid cartilage with the thumb index finger then move the fingers caudally until a space is felt between the thyroid cricoid cartilages.
FIGURE 1. Anatomy of the cricothyroid membrane.
- Failure to secure a surgical airway in an emergency or “cannot intubate, cannot ventilate” situation is most likely due to operator inexperience or a delay in the decision to obtain a surgical airway.
- The use of training with cadavers improves operator confidence (2).
- The use of simulator training shows improvement in operator skills placement time after practicing five times (3).
- The number of practice procedures appears to be more important in determining success than the technique chosen
- However, one study found that the Seldinger technique resulted in a significantly shorter time to first ventilation fewer injuries than with the surgical technique (4).
- Immediate complications include the following:
- Bleeding; although less likely than with tracheostomy placement, it can be significant if a large neck vein is lacerated.
- Insertion into subcutaneous tissue
- Scalpel injury to the posterior trachea injury to the esophagus
- Injury to the thyroid, vocal cords, vessels in the event of wrong lmarks
- Jet ventilation via a needle or cannula cricothyroidotomy has the risk of barotrauma, pneumothorax, subcutaneous emphysema, hypercarbia.
- Although emergency airway situations “cannot intubate, cannot ventilate” situations can arise at anytime, the majority occur during the induction of anesthesia.
- The anesthesia practitioner must have the ability to quickly recognize when an airway becomes difficult formulate a plan for securing a method of ventilation.
- When a “cannot intubate, cannot ventilate” situation arises, the American Society of Anesthesiologists (ASA) Difficult Airway Algorithm should be followed. Upon failure of an laryngeal mask airway (LMA) or alternative noninvasive technique to secure the airway, a surgical cricothyroidotomy should be performed (1). Poor outcome is related to length of time taken to make the decision to convert to surgical airway time taken to perform the technique.
- All techniques include the following:
Surgical technique: Use a number 20 scalpel to make a horizontal or vertical incision through the skin followed by a horizontal incision through the cricoid membrane. Place a tracheal hook at the incision site, apply caudal outward traction to the cricoid cartilage. Remove the blade. Place a cuffed tracheal tube or tracheostomy tube inflate. Confirm ventilation with end-tidal CO2 (ETCO2) bilateral breath sounds.
FIGURE 2. Surgical cricothyroidotomy.
An incision with a scalpel is made in the skin, followed by a horizontal incision through the cricothyroid membrane. An endotracheal tube or tracheostomy is inserted.
Seldinger technique (various kits are available): Stabilize the thyroid cartilage make a vertical incision in the skin over the cricothyroid membrane. Insert the 19 g catheter with a 5 cc syringe attached aspirate for air to confirm entry into the trachea. Secure the catheter with the non-dominant h remove the syringe needle. Advance the guidewire through the catheter then remove the catheter. Feed the dilator airway catheter over the wire. Remove the dilator wire simultaneously. Connect the airway catheter to an AMBU bag or ventilator confirm ETCO2 bilateral breath sounds.
FIGURE 3. Seldinger technique needle cricothyroidotomy utilize a needle attached to a syringe to identify access the airway.
The catheter is left in place the needle syringe are removed.
FIGURE 4. Seldinger technique.
Once the airway has been accessed (as in Figure 3), a guidewire is threaded through the catheter the catheter is removed. The dilator with the airway catheter is then inserted over the guidewire the guidewire dilator are removed at the same time.
- Needle (cannula) cricothyroidotomy technique: Performed by placing a needle with a catheter (such as a large-bore IV) through the cricothyroid membrane. Using a syringe attached to the needle, aspirate air to confirm that the trachea has been entered. Leave the catheter in place remove the needle. To ventilate via the catheter, attach a jet nozzle use jet ventilation. When initiating jet ventilation, the starting pressure should be set at 25 psi increased as needed. The maximum pressure should not exceed 50 psi, if possible, to provide acceptable ventilation. If jet ventilation is unavailable, remove the plunger from a 3-mL syringe; attach the syringe to the catheter. Insert the connector of a size 7.0 endotracheal tube into the syringe, then connect an bag or ventilator. This airway should be converted to a tracheostomy within 45 minutes, as the risk of hypercarbia is significant.
