INTRODUCTION — Needle cricothyroidotomy involves passing an over-the-needle catheter through the cricothyroid membrane (figure 1). This procedure provides a temporary secure airway to oxygenate and ventilate a patient in severe respiratory distress in whom less invasive techniques (eg, bag-valve-mask ventilation, laryngeal mask ventilation, endotracheal intubation) have failed or are not likely to be successful (ie, "can't intubate, can't ventilate") [1-4]. The delivery of oxygen to the lungs through an over-the-needle catheter inserted through the skin into the trachea using a high pressure gas source is considered a form of conventional ventilation called percutaneous transtracheal ventilation (PTV).
Although sometimes a point of confusion, PTV should not be mistaken for transtracheal jet ventilation, which is not considered conventional ventilation and refers to high frequency, low tidal volume ventilation and needs specialized ventilators usually only available in the operating room or intensive care unit. Although a technically different treatment, the term "jet ventilation" has also been used to describe conventional ventilation using a high pressure oxygen source via a percutaneous catheter [5-7].
Needle cricothyroidotomy differs from surgical cricothyroidotomy in that surgical cricothyroidotomy involves making an incision in the cricothyroid membrane and passing a tracheostomy or endotracheal tube through it into the trachea [4]. Needle cricothyroidotomy may be performed on patients of any age but is considered to be preferable to surgical cricothyroidotomy in infants and children up to 10 to 12 years of age because it is anatomically easier to perform with less potential damage to the larynx and surrounding structures [8-11]. However, surgical cricothyroidotomy provides more effective ventilation than needle cricothyroidotomy because of the larger diameter tube used and is typically chosen instead of needle cricothyroidotomy in adults and children over 10 to 12 years of age.
Needle cricothyroidotomy and percutaneous transtracheal ventilation will be discussed here. Surgical cricothyroidotomy is discussed separately. (See "Emergent surgical cricothyrotomy (cricothyroidotomy)".)
DEFINITIONS — It is important to distinguish between the different methods of emergency airway access and specialized ventilation. For the purposes of this review, definitions are as follows:
Needle cricothyroidotomy — Needle cricothyroidotomy involves passing an over-the-needle catheter through the cricothyroid membrane (figure 1).
Surgical cricothyroidotomy — Surgical cricothyroidotomy is an emergent airway approach in which the clinician makes an incision in the cricothyroid membrane and passes a tracheostomy or endotracheal tube into the trachea. The standard, four step, and Seldinger techniques are common methods of surgical cricothyroidotomy. (See "Emergent surgical cricothyrotomy (cricothyroidotomy)".)
Percutaneous transtracheal ventilation — Percutaneous transtracheal ventilation (PTV) involves oxygenation and ventilation via a needle or surgical cricothyroidotomy using an improvised ventilation device. Confusingly, although this is a form of conventional ventilation, it is sometimes referring to as "jet ventilation" when a high pressure source is used to deliver oxygen. (See 'Bag-valve-mask connector options' below and 'Oxygen tubing connector options' below.)
Transtracheal jet ventilation — Transtracheal jet ventilation refers to high frequency, low tidal volume ventilation provided via a laryngeal catheter by specialized ventilators that are usually only available in the operating room or intensive care unit [5,6]. This procedure is occasionally employed in the operating room when a difficult airway is anticipated (eg, Treacher Collins syndrome, Robin sequence, head and neck surgery with supraglottic or glottic obstruction) [12-15].
INDICATIONS — The primary indication is inability to maintain the airway with noninvasive standard airway procedures (eg, bag-valve-mask ventilation, endotracheal intubation) or rescue procedures (eg, laryngeal mask airway). The typical setting involves patients with pathologic processes that cause distortion of the upper airway anatomy, for example [3,16-18]:
CONTRAINDICATIONS
Absolute — Needle cricothyroidotomy with percutaneous transtracheal ventilation (PTV) is absolutely contraindicated when the airway is maintainable through noninvasive means.
In addition, needle cricothyroidotomy with PTV should not be performed when damage to the larynx, cricoid cartilage, or trachea preclude successful oxygenation and ventilation via a transtracheal catheter, for example:
Relative — Several relative contraindications arise in situations where anatomic distortion increases the risk of airway complications or where excessive bleeding may be encountered during needle cricothyroidotomy and PTV as follows:
However, in most instances, the benefit of securing an airway will outweigh the risk of performing needle cricothyroidotomy in these circumstances.
PRECAUTIONS
Complete upper airway obstruction — In routine use of percutaneous transtracheal ventilation (PTV) through a catheter, much of the expired air comes out of the mouth and nose. Thus, with complete upper airway obstruction, egress of expired air is difficult. Initial studies in animals suggested that PTV in the setting of complete upper airway obstruction led to development of massive distension of lungs, severe barotrauma, and death [19]. Subsequent studies have shown successful use of PTV in settings of complete upper airway obstruction using modified techniques that consist of prolonged expiratory time, larger internal diameter catheters, and lower oxygen flow rates [20-22].
PTV may be used successfully in partial laryngeal obstruction as the "ball-valve" effect, while constraining natural inspiration, adequately permits exhalation [14,23-25]. For infants and young children with complete upper airway obstruction and where other methods have been unsuccessful, it is reasonable to use PTV. Ventilatory methods should use a longer expiratory time (eg, I:E ratio of 1:8 to 1:10), lower oxygen delivery pressure and flow rate, and as large a catheter as possible. In addition, the clinician should carefully monitor for chest rise and fall with inspiration and expiration. Diminished chest fall with expiration should lead to further reduction in respiratory rate, longer expiratory time, and emergent chest radiography to look for signs of pulmonary barotrauma. (See 'Performing transtracheal ventilation' below.)
ANATOMY — The cricothyroid membrane, as the name implies, is bound by the cricoid cartilage inferiorly and the thyroid cartilage superiorly (figure 1). The key anatomic landmarks are (from cephalad to caudad): hyoid cartilage, thyroid cartilage, cricothyroid membrane, cricoid cartilage, and the tracheal rings.
In older children and adolescents, the laryngeal prominence at the upper border of the thyroid cartilage is easily felt. The thyroid cartilage can then be followed inferiorly to locate the cricothyroid membrane.
In infants and younger children, the laryngeal prominence is not developed, making it difficult to identify the thyroid cartilage. Instead, it is easier to follow the tracheal rings superiorly to locate the prominence of the cricoid cartilage. The cricothyroid membrane is located just superior to the cricoid cartilage. If the cricothyroid membrane cannot be located with certainty in an infant or a young child, percutaneous transtracheal ventilation can be safely performed by introducing the needle between the tracheal cartilages [12].
The cricothyroid arteries and veins usually overlie the apical portion of the membrane and come from the sides, anastomosing in the midline [26]. Thus, needle cricothyroidotomy should be attempted in the central, lower portion of the membrane (figure 1).
In fresh adult cadavers, the size of the cricothyroid membrane was found to vary from 8 to 19 mm (mean 13.7 mm) in the vertical dimension, and from 9 to 19 mm (mean 12.4 mm) in the transverse dimension [27]. These data suggest that catheters up to 13-gauge can be safely used in a patient with a fully developed airway. The cricothyroid membrane has a mean height of 2.6 mm (SD: 0.7) and width of 3 mm (SD: 0.6) in neonatal cadavers (mean height of 44.9 cm and a mean weight of 2 kg) [28]. The clinician should place the largest catheter possible using this limited information and palpation of the cricothyroid membrane as a guide. The mean depth of tissue overlying cricothyroid membrane in adults is about 2.3 mm [29].
PHYSIOLOGY — Needle cricothyroidotomy was originally used for passive transtracheal oxygenation in the 1950s [30]. Eventually, needle cricothyroidotomy with percutaneous transtracheal ventilation (PTV) emerged as the invasive rescue method of choice because it provided oxygenation as well as clearance of carbon dioxide. This approach could sustain life for a longer period of time than passive transtracheal oxygenation alone [1,12,31-33]. Smith and Ravussin were among the first to document successful use of needle cricothyroidotomy with PTV in infants and children in the 1970s [12,34].
Delivered tidal volume during PTV is affected by multiple factors, including inspiratory pressure, duration of inspiration, airway resistance, size of catheter, and lung compliance [33,35]. PTV is less efficient than ventilation through endotracheal intubation because up to one-third of oxygen flow delivered to the catheter tip passes up through the glottic opening and out the nose and mouth [32,35]. High pressure oxygen delivery systems are optimal to provide effective ventilation through the relatively narrow catheters used for PTV. However, low pressure systems (eg, self-inflating bag connected to the cricothyroidotomy catheter via a 3.0 mm internal diameter endotracheal tube adapter, 7.0 mm ID ETT adapter connected through a 3 cc syringe, (figure 2)) are sufficient in most patients if a high flow oxygen system is not available [2,6,36,37]. (See 'Equipment' below.)
In adults, PTV is typically accomplished using a 50 pounds per square inch (psi) (350 kPa) oxygen source and a 13- to 16-gauge over-the-needle catheter [3,25,32]. Marr and Yamamoto showed that catheter size (13- to 16-gauge) does not appear to substantially affect gas flow rates when using wall outlet oxygen because gas flows in a turbulent fashion under high pressure through these narrow catheters [36]. Large cannula (>4 mm), inserted via the Seldinger technique, enable ventilation with lower pressures in adults but require either a cuff or upper airway obstruction to prevent gas from escaping through the upper airway [6].
Lower driving pressures (25 to 35 psi [172 to 241 kPa]) are used in infants and younger children (under 12 years of age) in order to prevent barotrauma [12]. Smaller catheters (16- to 18-gauge) are typically placed due to the anatomic limitation posed by the cricothyroid membrane in the pediatric population. (See 'Anatomy' above.)
Once ventilation is established, exhalation through the transtracheal catheter is insufficient to prevent hyperinflation of the lungs. However, in most instances where PTV is used, the patient's airway remains sufficiently patent to permit exhalation through the nose and mouth [3,24]. In situations where complete airway obstruction exists, the clinician should use longer expiratory time and lower oxygen delivery pressure. In addition, chest rise and fall with inspiration and expiration should be carefully monitored. Diminished chest fall with expiration should lead to further reduction in respiratory rate, prolongation of expiratory time, and emergent chest radiography to look for signs for pulmonary barotrauma. (See 'Performing transtracheal ventilation' below.)
PTV provides less efficient ventilation than endotracheal intubation. Because of the concern for carbon dioxide retention with PTV, the traditional approach has been to use it as a short term (eg, less than 45 minutes) temporizing airway measure [7]. However, when oxygenation is well maintained, even relatively high levels of hypercarbia may be well tolerated, thus permitting its use for many hours at a time [2,7,38]. Regardless, the clinician should still rapidly seek to definitively secure the airway in most patients who require PTV, especially in settings complicated by increased intracranial pressure (because hypercarbia worsens intracranial pressure) or complete upper airway obstruction (increased risk of barotrauma).
There is no risk of gastric dilatation with needle cricothyroidotomy and PTV. The flow of gas up the airway aids in the expulsion of secretions, minimizing the need for suction and preventing pulmonary aspiration [32,39].
Using a canine model, researchers showed that it is not necessary to induce paralysis when using PTV for emergency ventilation of a sedated patient [40].
PREPARATION
Evaluation — Needle cricothyroidotomy with percutaneous transtracheal ventilation (PTV) is an invasive emergent airway procedure that is life saving, albeit with significant potential morbidity. Thus, proper patient selection is essential. The key indication consists of inability to maintain a patient's airway utilizing noninvasive means (eg, bag-valve-mask ventilation, endotracheal intubation, laryngeal mask airway). These patients cannot be intubated and cannot be ventilated. Proposed criteria include [7]:
AND
AND
Pathologic processes that cause distortion of the upper airway anatomy comprise the typical scenarios. (See 'Indications' above.)
The presence of subcutaneous emphysema in the neck may indicate tracheal or cricoid injury and is typically a contraindication to the use of this procedure as is transection of the trachea with retraction of the distal end into the mediastinum. (See 'Contraindications' above.)
Special precautions are needed for infants and young children with complete upper airway obstruction, as in the case of a tight foreign body obstructing the larynx. (See 'Complete upper airway obstruction' above.)
Patient counseling/informed consent — Needle cricothyroidotomy with percutaneous transtracheal ventilation is usually an emergent procedure that does not allow for patient counseling/informed consent prior to the procedure. However, the procedure's necessity, benefits, and risks should be explained to the patient and/or caretaker at the earliest possible time after completion. If feasible, it is ideal for a member of the team not directly involved with the resuscitation to explain the procedure to the family as it is being done.
Equipment — Needle cricothyroidotomy and percutaneous transtracheal ventilation can be performed using standard materials readily available in any hospital. Commercial setups are also attainable [3,7,41,42]. To ensure maximum effectiveness in a highly stressful emergent setting, the author recommends that equipment for PTV, including all the necessary components, be organized and readily available [43].
General equipment
Catheter (large bore) — AVOID needleless safety catheters that cannot be connected to a syringe (eg, BD InSyte™ Autogard™) [12,44].
Bag-valve-mask connector options — If a bag-valve-mask will be used for patient ventilation, then it should connect to the catheter using one of the following improvised adapters:
Oxygen tubing connector options — If oxygen tubing will be used to connect to the oxygen source, then the clinician may use one of the following options:
High pressure oxygen source — One of the following oxygen sources is recommended:
DO NOT USE the common gas outlet of the anesthesia machine, as most machines have a pressure limiting valve on the back bar which opens at 5 psi (35 kPa) [46].
Oxygen tubing or equivalent — The tubing must be capable of withstanding high pressure.
Manual in-line valve — The setup must control intermittent flow of oxygen and ventilate the patient, examples include:
PROCEDURE — Percutaneous transtracheal ventilation is summarized in the table (table 1 and figure 7).
General considerations — Place the patient in the supine position on the stretcher. Unless there is a cervical spine injury (known or suspected), extend the patient's neck to help identify the procedural landmarks and to obtain the widest exposure of the cricothyroid membrane. While assembling the equipment for the procedure, ask an assistant (preferably the respiratory therapist) to preoxygenate the patient by administering high-flow oxygen via face mask if the patient is breathing spontaneously or via bag-valve-mask if not.
Site verification — The clinician should locate the cricothyroid membrane by palpating the prominence of the thyroid cartilage in older children, adolescents, and adults and moving the finger inferiorly into the depression between the thyroid and cricoid cartilages.
In infants and young children, the clinician should palpate the trachea just above the suprasternal notch and move superiorly until the prominence of the cricoid cartilage is felt. The needle should be placed just above the cricoid cartilage in the midline. If the cricothyroid membrane cannot be located with certainty in an infant or a young child, percutaneous transtracheal ventilation (PTV) can be safely performed by introducing the needle between the tracheal cartilages [12]. (See 'Anatomy' above.)
Although not studied in children, investigators have demonstrated the ability to accurately and rapidly identify the cricothyroid membrane in adult cadavers and live patients using bedside ultrasonography [29].
.
Analgesia and sedation — Under emergent circumstances there may not be time to administer sedative or analgesic medications. The most important goal is to secure the airway. In the case of respiratory depression or arrest, sedation may make matters worse and is not advised. However, if the patient is agitated and struggling and this behavior is impeding the progress of the procedure, a sedative and analgesic can be given to help control the patient.
Paralysis or subsequent continuation of paralysis may be considered based on the patient's response to the procedure and adequacy of ventilation achieved. In canine studies, PTV without paralysis has been achieved in sedated animals with unobstructed airways [40].
Skin preparation — Prepare the skin of the anterior neck with an antiseptic solution (eg, povidone-iodine). If time permits, anesthetize the skin, subcutaneous tissues, and the cricothyroid membrane with a local anesthetic such as 1 percent lidocaine administered through a 27- or 30-gauge needle.
Monitoring — Monitor heart rate and rhythm, blood pressure, respiratory rate, and oxygen saturation throughout the procedure. Lower the patient's gown and sheet to observe the rise and fall of the chest with respiration. Capnography should be used as feasible both during the procedure (to ensure intratracheal location of the needle or the catheter) and during patient ventilation [25,48].
Once the catheter is in place and percutaneous transtracheal ventilation is established, the site of needle cricothyroidotomy should be observed closely for any kinking or dislodgement of the catheter, subcutaneous emphysema (may indicate dislodgment of the cannula), or bleeding [3]. Chest radiographs should be obtained to ensure that the lungs are not over-expanded. Adequacy of PTV should be assessed using clinical parameters as well as frequent blood gas analysis.
Method — (figure 7).
Needle cricothyroidotomy
Performing transtracheal ventilation
Cricothyroidotomy may also be performed rapidly and effectively using a modified Seldinger technique (wire-guided or catheter-over-needle technique). (See "Emergent surgical cricothyrotomy (cricothyroidotomy)", section on 'Seldinger technique'.)
COMPLICATIONS — Barotrauma and catheter issues that prevent transtracheal ventilation are the two most commonly described complications of percutaneous transtracheal ventilation (PTV) (table 2) [3,7,12,14,15,32]:
Subcutaneous emphysema after PTV typically resolves without intervention [3].
Other less common complications of needle cricothyroidotomy and PTV include damage to adjacent structures, bleeding, and infection (table 2) [7,49,50,52]. Although pulmonary aspiration may occur during PTV, in a canine model, it provided significant protection from aspiration relative to dogs with unprotected airways [39].
FOLLOW-UP CARE — Prolonged percutaneous transtracheal ventilation (PTV) is associated with excessive inspiratory workload, hypercapnia, barotrauma, and catheter dislodgement with subcutaneous emphysema [3,7,53]. Thus, a definitive airway (ie, endotracheal tube or tracheostomy) should be obtained as soon as possible after PTV is established. Emergent anesthesiology and otolaryngology consultation may be required, especially in patients with traumatic injury to the face and/or neck.
In non-traumatic cases, intubation, with direct laryngoscopy or guided by endoscope, is successful in the majority of cases. Subsequent intubation may be easier as the high tracheal pressure from expiratory gases tends to open the previously collapsed glottis, improving visualization of the glottic opening. In addition, there is reduced operator stress and more time to visualize, and if needed, suction the glottic opening [3,54].
SUMMARY
Definition
Indications and contraindications
Preparation and procedure
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