Percutaneous Transtracheal Jet Ventilation

Airway management is a priority in the resuscitation of critically ill patients. Generally, this can be achieved by means of basic or advanced airway maneuvers. As a bridge to a definitive airway, supraglottic devices such as a laryngeal mask airway (LMA) or a King laryngeal tube (LT) can be employed. In a minority of patients, tracheal intubation fails, and a surgical airway is required in order to secure the airway.[1] This group includes patients with upper-airway foreign bodies or neoplasms, maxillofacial trauma, laryngeal edema, or infection.

A surgical airway can be obtained in the emergency setting through one of the following two principal methods[1, 2] :

• Open surgical cricothyroidotomy (cricothyrotomy)
• Needle cricothyroidotomy

Needle cricothyroidotomy has commonly been held to provide simpler, faster, and safer access,[2, 3, 4]  though open cricothyroidotomy has been gaining favor.[5]

Percutaneous transtracheal jet ventilation (PTJV) was introduced in the 1950s by Flory et al. In the early 1970s, intermittent PTJV was successfully used for airway management during routine general surgical procedures lasting up to 2 hours. PTJV was also advocated as an alternative in the management of the difficult airway, in conjunction with laryngoscopy.

Some reports have recommended PTJV only as a transient resuscitative measure for emergencies in which endotracheal intubation or other ventilation methods are not feasible.[6, 7] PTJV is widely thought of as a temporizing procedure to be maintained for 30 minutes at most. However, animal experiments and clinical studies have demonstrated that transtracheal ventilation is an effective, quick, fairly simple, and safe way to obtain and maintain an airway for a prolonged period.[8]

At first, PTJV was not widely accepted, because of initial reports of high complication rates.[3, 9] It was also noted that PTJV does not provide definitive airway protection against copious secretions or aspiration.

Nevertheless, in a life-threatening situation where tracheal intubation and bag-mask-valve ventilation cannot be performed to restore adequate gas exchange during acute respiratory failure, it is reasonable to consider PTJV as a viable interim maneuver. Under such circumstances, PTJV with a large-bore needle provides immediate oxygenation and ventilation by providing adequate gas exchange and ensuring the patency of the airway until a definitive procedure (eg, oral intubation with bronchoscopy followed by surgical tracheostomy) can be performed[10] ; it requires fewer instruments than surgical cricothyroidotomy and can be performed more quickly.

Transtracheal jet ventilation has been used extensively as a means of ventilation during surgery and procedures of the upper airway.[11, 12, 13]  It may be used even with partial airway obstruction.[14] PTJV can force oropharyngeal secretions out of the proximal trachea and may force a foreign body out of the proximal trachea (in cases of partial airway obstruction). However, upper-airway patency is required for exhalation during PTJV, and an open cricothyroidotomy is preferred if significant obstruction exists.

PTJV is a rapid means for obtaining airway control in both elective and emergency situations for patients of all ages and in many clinical situations.[15, 16, 17] It is the surgical airway of choice for children younger than 12 years because of the small tracheal diameter, which often renders an open cricothyroidotomy impossible. Although rarely performed, needle cricothyroidotomy is a potentially life-saving procedure.

The range of adapted equipment presently used for needle cricothyroidotomy is diverse. This article describes and demonstrates a method of PTJV and oxygen delivery for needle cricothyroidotomy that is easily accessible, simple to assemble, easy to use, and readily available in every emergency setting.

Indications for PTJV are similar to those for surgical cricothyroidotomy.

PTJV is indicated in any situation where intubation is contraindicated or cannot be achieved.[18]

The failure or inability to secure a definitive airway by endotracheal intubation in a timely fashion, with a subsequent inordinate delay in definitive airway control and oxygenation, is an indication for either needle or surgical cricothyroidotomy to prevent hypoxemia.

PTJV has also been used electively in patients of all ages and as a rescue procedure.

PTJV is the surgical airway of choice for children younger than 12 years.

Absolute contraindications for PTJV are as follows:

• If a definitive airway can easily and rapidly be secured with endotracheal intubation, PTJV is not used
• PTJV is not used in the presence of known significant direct damage to the cricoid cartilage or larynx ^[18]

Relative contraindications for PTJV are as follows:

• If complete upper-airway obstruction is present, surgical cricothyroidotomy is preferred over PTJV ^[19]
• PTJV can be used in the presence of partial airway obstruction, provided that appropriate-sized catheters are used ^[19]
• Airway obstruction below the vocal cords that renders exhalation difficult or impossible is a relative contraindication

For cases of difficult airway management in adult coronavirus disease 2019 (COVID-19) patients, when emergency invasive airway access is required, the Society of Airway Management recommended a surgical approach, such as scalpel-bougie-tube, rather than an aerosolizing generating procedure, such as transtracheal jet ventilation.[20]

Anatomy

The anterior neck allows direct access to the airway via the trachea. At the cephalad aspect of the laryngeal skeleton is the thyroid cartilage, which lies at the level of the fourth and fifth cervical vertebrae. The laryngeal prominence of the thyroid cartilage (more prominent in men) is easily palpated with the thumb and index finger. The cricoid cartilage lies just inferior to the thyroid cartilage in the midline.

Between the cricoid and thyroid cartilages lies the cricothyroid membrane. The cricothyroid membrane is a palpable membranous depression just inferior to the laryngeal prominence and is the access site for PTJV.

The cricothyroid artery travels transversely across the cricothyroid membrane just below the thyroid cartilage. Therefore, it is essential to place the catheter through the lower half of the cricothyroid membrane so as to prevent injury to the artery.

Equipment for needle cricothyroidotomy (cricothyrotomy) and percutaneous transtracheal jet ventilation (PTJV) consists of the following[7, 21] :

• High-pressure noncollapsible oxygen tubing
• Needle catheter, 13 or 14 gauge
• Oxygen source with a flow at 10-15 L/min
• Manual jet ventilator/insufflator device

If a manual jet ventilator/insufflator device is not available, needle cricothyroidotomy and PTJV can be performed with equipment that is readily accessible in emergency settings, is simple to assemble, and is easy to use. This equipment includes the following:

• Oxygen source with a flow at 10-15 L/min
• Commercial bag-valve-mask device (eg, Ambu bag) that includes noncollapsible oxygen tubing and a reservoir bag
• Large-bore over-the-needle intravenous (IV) catheter (14 gauge; 2 in. [5 cm])
• Plastic syringe, 3 mL, ^[4] with Luer-Lok tip that fits tightly into a 7.5-mm inner diameter endotracheal tube adapter
• Endotracheal tube adapter, 7.5 mm inner diameter

Equipment assembly

Connect the IV catheter to a 3-mL syringe barrel (with its plunger removed). Connect the 3-mL syringe barrel to the 7.5-mm inner diameter endotracheal tube adapter.

Lock the valve of the bag-valve-mask device, and connect its oxygen tubing to an oxygen source with a flow at 10-15 L/min. Connect the endotracheal tube adapter to the bag-valve-mask device.

Manually ventilate, alternating 1 second of compression with 4 seconds of relaxation (ventilations are guided with chest rise).

Anesthesia

Lidocaine 1-2% at a dose of 2-3 mL is generally sufficient for local skin anesthesia via infiltrative administration in patients who are alert and awake. Injection of a small amount of anesthetic percutaneously into the trachea itself will blunt the cough response as well.

For more information, see Local Anesthetic Agents, Infiltrative Administration.

Positioning

The patient ideally should be positioned to expose the neck and its landmarks (see the image below). If no contraindications are present (eg, known or suspected cervical spine injury), the patient's head should be placed in a hyperextended or "sniffing" position. Extension of the neck facilitates identification of the anatomy and control of the cricoid space.

The cricothyroid membrane is located by identifying the dip or notch in the neck below the laryngeal prominence. This membrane is bounded by the thyroid cartilage superiorly and the cricoid cartilage inferiorly. The landmarks are most easily found by placing the index finger on the prominence of the thyroid cartilage and slowly palpating downward until the finger "drops off" the thyroid cartilage and onto the cricoid membrane.

Airway protection during PTJV is accomplished by positioning the patient to allow drainage of secretions away from the larynx during expiration, so that upward gas flow through the larynx causes secretions and blood (for example) to be blown away from the larynx.

Before percutaneous transtracheal jet ventilation (PTJV) can begin (see the first video below), a needle cricothyroidotomy (cricothyrotomy) must be performed (see the second video below.)

Needle cricothyroidotomy

Position the patient as previously described (see Patient Preparation).

Attach a small (3-5 mL) syringe containing 1-2 mL of sterile normal saline or water to a large-bore needle (13 or 14 gauge). A small bend in the distal 2.5-cm segment of the needle can facilitate advancing the catheter once the trachea has been cannulated. There are also commercially available catheters with a slight bend at the tip that are made specifically for PTJV.

Some advocate that 2 mL of lidocaine be sprayed into the larynx/trachea percutaneously to suppress the cough reflex. If the patient is alert or concern exists about the cough reflex, prepare another 5-mL syringe containing 4 mL of 1% lidocaine with a 25-gauge needle. Use 1-2 mL of the lidocaine to anesthetize the skin overlying the cricothyroid membrane. Then advance the needle through the cricothyroid membrane and spray the remaining 2 mL of 1% lidocaine into the trachea. Then remove the needle and syringe.

While the dominant hand holds the syringe and needle containing saline, with the needle directed caudally at 30-45° to the skin, hold and stabilize the larynx with the nondominant hand. Stabilize the cricoid cartilage with the thumb and middle fingers of the nondominant hand, and palpate the cricothyroid membrane with the nondominant index finger.

Insert the needle through soft tissues, skin, and the cricothyroid membrane (see the image below). The cricothyroid membrane should be punctured in the inferior aspect (ie, nearer the cricoid cartilage than the thyroid cartilage) so as to avoid puncturing the cricothyroid arteries.

While exerting negative pressure on the barrel of the syringe, insert the needle through the cricothyroid membrane into the larynx. Air bubbles in the fluid-filled syringe signify entry into the larynx. After entering the larynx, advance the cannula into the larynx and trachea, and then remove the needle.

If much resistance is encountered when the needle or catheter is passing through the skin, subcutaneous tissue, or cricothyroid membrane, kinking or bending of the catheter may occur unless a stiffer catheter is used. A small nick in the skin may be needed to facilitate passage through the dermis into the subcutaneous tissue. A percutaneous dilational or Seldinger guide wire technique may result in fewer complications.[22, 23]

Secure the cannula by suturing it to the skin or by placing a circumferential tie around the neck. The proximal end of the cannula must be snug or tightly fitting and securely held around the puncture wound opening. If the cannula is not securely held in place, subcutaneous emphysema may result, the cannula may be dislodged from the larynx, or both.

Connect the oxygen source to the cannula.

Percutaneous transtracheal jet ventilation

A trial of several bursts of oxygen flow is recommended to make certain that the cannula is correctly placed and that the setup is working and ventilating properly. (See the image below.)

The hypoxic patient should receive 100% oxygen in intermittent bursts of less than 50 psi at a rate of 20 bursts/min. For this, an oxygen source capable of 50 psi is needed, along with a regulator to ensure delivery of no more than 50 psi. For children, 30 psi has been recommended. The fraction of inspired oxygen (FiO2) can then be adjusted, depending on blood gas laboratory results.

The inspiratory phase or insufflation with the burst of oxygen should last approximately 1 second, and the expiratory phase should last long enough to allow for adequate exhalation, typically 3-4 seconds.[6]  An adequate expiratory phase is important to minimize the risk of barotrauma.

Complications that may occur with PTJV include the following:

• Aspiration
• Bleeding
• Pneumothorax
• Subcutaneous  emphysema
• Barotrauma (eg, pneumothorax, pneumomediastinum)
• Catheter-related problems (eg, obstruction or blockage of the catheter, kinking of the catheter, catheter displacement, or misplaced or unsuccessful needle or catheter placement) ^[9]
• Inadequate ventilation ^[22]

The exact incidence of such complications is not known, but it is thought to be low, given that the complication rate of translaryngeal puncture alone is in the range of 0.03-0.8%.[24]  In a study that examined the use of transtracheal jet ventilation in 50 patients with severe airway compromise who underwent pharyngolaryngeal surgery, the incidence of minor complications was 12%.[25]

Disadvantages of PTJV include the following:

• Incomplete control of the airway with subsequent greater potential for aspiration than with a cuffed endotracheal tube
• Potential for barotrauma (subcutaneous emphysema or pneumothorax) if exhalation is inadequate and airway pressure is elevated

A systematic review by Duggan et al found that PTJV was associated with a high risk of device failure and barotrauma in the setting of "can't intubate, can't oxygenate" (CICO) emergencies.[26]