CE Article: Surgical Cricothyrotomies in Prehospital Care

“Medic 12, respond to Route 12b, approximately one mile south of the Utica city line, reported car versus train. Your dispatch time is 1630.” Anthony and Kit, both experienced paramedics, begin their response. Upon arriving on scene, they see the fire department and police have already ensured the road is shut down and are extricating their mid-20s male patient from a severely damaged SUV. When Anthony approaches the car, a firefighter/EMT inside the car advises him that, “I’ve been trying to keep his airway open with suction and a jaw thrust, he’s completely unresponsive, but his jaw is shattered and moves in pieces. I don’t think we can ventilate him once he is laid flat. I can’t get a seal with a BVM with the jaw like this.”

Once extricated, Anthony attempts to ventilate the patient with a BVM and confirms that with a two-person mask seal it is not possible. While Kit prepares his surgical cricothyrotomy equipment Anthony attempts to perform endotracheal intubation, finding their patient’s mouth quickly fills with blood faster than it can be suctioned. Looking at Kit, Anthony calmly tells him, “Go ahead and perform a cricothyrotomy, there’s no way we can intubate.”

Introduction

While infrequent, an emergency cricothyrotomy is a life-saving intervention paramedics may have in their scope of practice and may be credentialed to perform. The cricothyrotomy is the most invasive rescue airway skill and is indicated only when all other means for ensuring effective and safe ventilations are impossible or have failed.

While terms are often interchanged, any procedure which accesses the trachea for the purposes of ventilation and airway access via the cricothyroid membrane is by definition a surgical cricothyrotomy. There are three strategies for a surgical cricothyrotomy: needle cricothyrotomy, Seldinger cricothyrotomy, and open cricothyrotomy. For the purposes of this article the term “cricothyrotomy” describes the procedure generically and includes all three of these techniques.

Cricothyrotomies are not common anywhere in emergency medicine. Hospital-based studies have reported that surgical cricothyrotomies are performed in less than 1% of patients requiring airway management.1 Outside of the hospital, this procedure is only slightly more common. A recent analysis published in early 2014 reviewed over 4,800 prehospital intubation encounters by 78 air medical transport teams. The researchers found cricothyrotomies were performed on only 35 patients (0.7%). Providers were successful in 33 of the 35 cases, which is a 94% success rate.2 When compared to a 1996 study in the Journal of Trauma on prehospital cricothyrotomy, where 9.8% of patients needing an advanced airway received cricothyrotomy,3 there is a clear decline in the frequency of cricothyrotomy performance compared to overall prehospital airway management cases. This drop in frequency is likely associated with improved airway management training, the implementation of prehospital rapid sequence intubation (RSI) programs, and the introduction of adjuncts such as the gum-elastic bougie, supraglottic devices and video laryngoscopy, as well as the removal of this skill from some systems.

However, do not think this means a paramedic doesn’t need to master cricothyrotomy; rather, it signals the need for increased practice on a skill that an individual will likely only perform a few times in their career and which will always be performed in a high-stress environment. This is further evidenced by a study that reviewed all of the emergent surgical cricothyrotomies received and performed at two level 1 trauma centers. Researchers found every prehospital-placed surgical airway had serious complications, ranging from major bleeding to airways placed in the cervical fascia (a false lumen).1

Indications

A definitive airway is defined as the placement of a cuffed tube in the trachea past the vocal cords. Definitive airways are indicated whenever a patient cannot protect their own airway, cannot effectively ventilate and when paralysis is indicated for patient protection (e.g., presumed head injury). Once the decision is made that a patient requires definitive airway management, be confident with the decision. Don’t abandon advanced airway placement because the first initial strategies to secure the airway fail.

Definitive airway management can be accomplished with a variety of methods and adjuncts including video and direct laryngoscopy, and surgical cricothyrotomy. When they provide effective ventilation, blind insertion devices such as the King-LT, Combitube, Laryngeal Mask Airway (LMA) and others can be safe and effective bridging devices until definitive airways can be placed, but are not considered a definitive airway because they do not place a cuffed tube in the trachea beyond the vocal cords. By using a tube with a cuff it becomes possible to prevent aspiration and control air pressure within the respiratory system. Simply stated, a surgical cricothyrotomy is indicated when you can’t intubate, can’t ventilate and can’t maintain a SpO2 greater than 90% for your patient. Contrary to popular belief, a cricothyrotomy does not need to be a last ditch effort. Instead, think of them as just another strategy for establishing a definitive airway. In fact, there are times, such as respiratory arrest in anaphylaxis or upper airway obstruction, when cricothyrotomy could be the first choice in airway management.

There are a many situations that can lead to a “can’t intubate, can’t ventilate” situation. The most common reasons for prehospital cricothyrotomy include clenched jaw, blood and vomit impairing airway visualization despite suction, massive maxillofacial injury, and limited patient access due to entrapment.3 While most of these situations are related to trauma, non-trauma airway compromise can require surgical cricothyrotomy and are noted in Table 1.

Keep in mind cricothyrotomy does not mean the airway is totally occluded; rather, it means the airway is compromised in a manner that prevents effective ventilation. This is an important distinction that becomes critically important when selecting the tools and method for the procedure.

Contraindications for emergency cricothyrotomy can be debated to a degree. On one aspect, the patient is likely to die or suffer an anoxic brain injury without intervention. On the other, improper placement and procedure can also be fatal. The only true absolute contraindication for an emergency cricothyrotomy is the inability to identify the anatomical features necessary to perform the procedure.

Generally emergent surgical cricothyrotomy is not indicated in younger than 12 years of age. Needle cricothyrotomy is the preferred method in this young age group; however, references differ on the low age limit for needle cricothyrotomy placement being between 124 and 5 years of age.5 In reality, the lower age limit for a cricothyrotomy is due to the size and features or a child’s airway rather than their age. Younger children have a narrower cricothyroid membrane and a trachea and larynx that have a funneled shape that is softer than the adults. These differences increase the likelihood of causing excessive bleeding in an already small airway and accidently placing the airway in a false lumen or puncturing completely through the trachea with the tools used to perform a cricothyrotomy.

The mnemonic SHORT can be used to remember reasons to proceed cautiously when selecting surgical cricothyrotomy. SHORT stands for: Surgery (evidence of prior), Hematoma, Obesity, Radiation therapy evidence, and Trauma to the site. The presence of these conditions suggests an increased risk for complications, including increased bleeding and difficulty placing the airway. Other reasons to consider deferring a surgical cricothyrotomy include the presence of a tumor, abscess or other evidence of infection at the insertion site.

Identifying Landmarks

The cricothyroid membrane is the tissue between the cricoid and the thyroid membrane. Any “-otomy” is a hole by medical definition. Thus, a cricothyrotomy is the surgical placement of a hole in the cricothyroid membrane. With a patient laying supine and the head in a neutral midline position, palpate the thyroid cartilage, also known as the Adam’s apple. Immediately inferior to the thyroid cartilage is a small gap, the cricothyroid membrane. Moving inferior from the cricothyroid membrane is the cricoid cartilage; the thyroid gland attaches firmly to the lateral aspects of the cricoid cartilage by the Berry ligament. Physicians may perform surgical tracheostomies below the thyroid gland; however, as noted in Figure 1, there are several great vessels below the thyroid gland. These blood vessels increase the risk of bleeding during procedures in this anatomical region and thus the region is best avoided. Figure 1 also illustrates the high concentration of vessels surrounding the trachea. This high concentration of vessels is one reason severe bleeding is common during surgical cricothyrotomy.

Pay particular attention to the small size of the cricothyroid membrane; it has an average vertical width of 9 mm and its horizontal length averages 30 mm. This gap is just large enough to accept devices roughly the size of a 6.0 ETT, which has an outer diameter of 8.2 mm. By comparison, the outer diameter of an 8.0 ETT is 11 mm. Some large patients may be able to accept a slightly larger airway through the cricothyroid membrane, although it is better to have a small and secure airway than it is to force in a larger airway and cause more damage.

Approach Considerations

There are three primary approaches to a cricothyrotomy:

Needle cricothyrotomy

Seldinger technique surgical cricothyrotomy

Open cricothyrotomy

Every provider needs to learn their system’s equipment and expectations and practice it regularly. Develop a systematic approach to the cricothyrotomy that is easy to repeat and execute. Additionally, be flexible and realize that each patient is different and each situation may require slight adaptation.

Whichever approach used, all demand a similar patient preparation and initial care. In most instances, all BLS and traditional ALS interventions should be attempted before progressing to cricothyrotomy. While critical thinking may suggest that only a cricothyrotomy will secure the airway, it’s reasonable to have one of the providers on scene attempt to open the airway and attempt BVM ventilations with a mask and/or other airway device while the cricothrotomy equipment is prepared. Since the inability to maintain a SpO2 above 90% is one of the indicators, it makes sense to apply pulse oximetry throughout the procedure. However, it’s understood the patient is likely already hypoxic and while intubation attempts cease as SpO2 decreases to 90%, the cricothyrotomy procedure should not. Rather, focus on performing cricothrotomy as smoothly and rapidly as possible. Accurate airway placement is more important than rapid airway placement.

The patient’s neck for all approaches is placed in a neutral mid-line position. Standardize your practice by always working from the same side of the patient. For those who are right handed, work from the patient’s right side, those who are left handed from the left side. This approach allows you an increased range of motion with your dominant hand without being obstructed by the chin. It is unnecessary to establish the patient in the sniffing, or head elevated, position for the procedure. However, tilting the head slightly backward—head extension—may help stabilize the trachea in place should cervical spine stabilization not be indicated.

Keeping in mind this is an emergency procedure, your priority is securing the airway. However, as soon as practical establish IV/IO access and administer an analgesic. Performing a surgical procedure on any individual is extremely painful, even when they are apparently unresponsive. If there is no time to administer an IV analgesic prior to establishing an airway, do so as soon as practical afterward. When available, consider injecting the skin of the neck with 2–3 mL of 1% lidocaine with epinephrine. This combination will reduce bleeding and numb the site as well. Injecting too much fluid prior to beginning a cricothyrotomy may impede your ability to palpate the cricothyroid membrane and other landmarks.

Needle cricothyrotomy is the fastest and least effective method for establishing a surgical airway. By placing a 10–14 gauge angiocath needle through the cricothyroid membrane, the needle cricothyrotomy permits effective oxygenation for about 40 minutes. However, the needle cricothyrotomy is ineffective at carbon dioxide elimination, so CO2 accumulates rapidly. Because of this, the effectiveness of needle cricothyrotomy has also been called into question as an effective airway strategy. A meta-analysis reviewing over 2,005 studies on prehospital airway management found only four studies demonstrating successful prehospital needle cricothyrotomy placement with success rates ranging from 25–77%.6

Further, a 2011 study on surgical airways demonstrated needle cricothyrotomy is ineffective at providing effective tidal volume delivery unless the airway above the cricothyroid membrane is essentially completely occluded. In this study, when the diameter of the upper airway remained open 3 mm or more, it was impossible to deliver tidal volumes over 87 mL.7 Although when total airway occlusion occurred, needle cricothyrotomy permitted a tidal volume of nearly 200 mL, which is considered adequate for oxygenation but not CO2 elimination.7 When using a needle cricothyrotomy on a non-occluded airway it may be necessary to close the upper airway to achieve effective ventilation.

When performing a needle cricothyrotomy prepare the following equipment:

Bag-valve mask

The 15 mL adapter off of a 3.5 ETT

An over-the-needle catheter appropriate for the patient’s age

A 10 mL syringe filled with 5 mL water

An antiseptic solution

Once your equipment is prepared, cleanse the neck with an antiseptic solution as you would an IV site. While iodine-based solutions are preferred, there likely isn’t time to let an iodine-based solution dry, which is the process by which iodine kills bacteria. It’s reasonable to consider another approved solution, such as chlorhexidine, may be used as long as its defined aseptic process is followed. Without the use of sterile gloves throughout this procedure, cleaning the skin likely has limited true value. Once cleansed, palpate and identify the cricothyroid membrane through the skin and:

Stabilize the skin and trachea with your non-dominant hand between your thumb and middle finger, leaving the index finger free to palpate the landmarks.

With the 10 mL syringe attached to your needle, insert the needle through the skin and cricothyroid membrane caudally at a 45⁰ angle.

While inserting the needle, aspirate with the syringe. Bubbles will appear in the syringe once you have penetrated the tracheal lumen.

Stop advancing the needle once bubbles are observed. Decrease your needle angle to 20⁰ and advance the catheter over the needle to its hub so it is completely within the trachea and then remove the needle.

Connect the 15 mL adapter from the 3.5 ETT to the catheter so a BVM may be attached. (Figure 2)

Control bleeding as necessary and stabilize with tape and manually.

With needle cricothyrotomy do not expect to see significant chest rise. This method allows oxygen to be forced into the lungs until a definitive airway can be established. An alternative method for oxygenation is by using a meconium aspirator and oxygen tubing. Attach the meconium aspirator to the 15 mm ETT adapter, and instead of attaching it to suction, connect it to an oxygen source with a flow of at least 15 liters per minute—the higher the better. Simply cover the hole in the meconium aspirator to oxygenate the patient and release it between breaths (Figures 3a and 3b).

Seldinger technique for surgical cricothyrotomy is faster than open cricothyrotomy and has less risk for major vessel injury.8 When using a commercially prepared device, the manufacturer’s packaging should include all of the equipment necessary to perform the procedure. Avoid using systems that require obtaining additional equipment not provided within their kit because time will be wasted assembling the additional equipment. The traditional equipment used for Seldinger technique includes:

A #11 or #10 scalpel

A trousseau dilator

A sterile guide wire

A tracheostomy tube or endotracheal tube

Bag-valve mask

The traditional Seldinger technique follows the initial steps for needle cricothyrotomy only with a needle rather than an angiocath. Then follow the following steps:

Isolate the trachea by inserting a guide wire through the needle and into the trachea and removing the needle

With a 10 gauge scalpel, cut the skin and cricothyroid membrane vertically along the wire

Insert a dilator through an tracheal tube and over the wire

Slide the tracheal tube and dilator into the trachea along the wire

Remove the wire and the dilator

Secure the device

It is uncommon to find an EMS system utilizing the traditional Seldinger technique. Rather, systems are using a manufactured device that uses the same dilation-based approach—such as the built-in dilator on the Quicktrach II—only without a guide wire. Dilation widens the hole created in the skin and cricothyroid membrane to create a passage through which a trach tube can more easily be passed.

Manufactured devices are available with and without a cuff. Uncuffed tracheal tubes such as the Quicktrach and Melker can produce tidal volumes over 500 mL when ventilating lungs with an occluded upper airway. However, their effectiveness is lost as the upper airway opening passes 5 mm. Cuffed tracheal tubes such as the Quicktrach II and the cuffed Meckler have been shown to effectively ventilate at tidal volumes exceeding 600 mL regardless of upper airway size.7

Retrospective studies have shown prehospital cricothyrotomies using a modified Seldinger technique can have success rates exceeding 90%, and be more consistently placed than a needle cricothyrotomy.6 It makes sense to use a device that has as few steps as possible. But whichever device is used, these authors strongly encourage only using devices that have an inflatable cuff.

Open cricothyrotomy ultimately allows a commercial tracheal tube or endotracheal tube to be placed into the trachea through an incision. Performing an open cricothyrotomy requires you obtain the following equipment:

6.5 ETT

Bag-valve mask

10 blade scalpel

A tracheal hook or hemostat

Gum-elastic bougie

Follow a four step rapid approach to the open surgical cricothyrotomy. (Figures 4–7)

Stabilize the thyroid cartilage with the non-dominant hand and then identify and make a 2–3 cm vertical incision over the cricothyroid membrane.

Stab the cricothyroid membrane with your scalpel and then insert either a tracheal hook or hemostats immediately inferior to the scalpel. With a tracheal hook pull inferior traction with slight elevation of the trachea. If using a hemostat, insert and open the device along the vertical plane of the cricothyroid membrane.

Insert the bougie gently caudally until you meet resistance (upon reaching the carina).

Insert the endotracheal tube over the bougie or in the hole beneath the tracheal hook.

While the gum-elastic bougie is traditionally used for oral tracheal intubation, it is a reasonable and proven introducer during surgical cricothyrotomy. Its use was first reported in 2008 and has since become more common.9 It make sense to incorporate the bougie into prehospital surgical cricothyrotomy as the bougie can be used in direct and video laryngoscopy as well.

Ongoing Training

Regardless of the surgical cricothyrotomy method or commercial device used, no provider will maintain proficiency without continuous practice. Simply reading about a procedure is inadequate and sets providers up for failure. Instead, insist on being allowed to perform hands-on practice at a minimum of once per year. In a study on the ongoing proficiency of surgical airway procedures in anesthesia residency, an increased procedure proficiency and protocol compliance was observed when simulation training occurred at 3, 6 and 12 month intervals, with the greatest compliance occurring at 3 month intervals.10

Surgical cricothyrotomy is not a procedure that can be practiced infrequently and have proficiency assumed. Many circles argue surgical airways should no longer be a prehospital skill. While this debate is ongoing, it’s important to prepare with regular practice. With increased practice comes increased confidence and competency.

Definitive Care

A cuffed tube placed in the trachea beyond the vocal cords is considered a definitive airway. That said, EMS is not a definitive environment. Tubes used in an emergency surgical cricothyrotomy will need to be replaced with either an endotracheal tube or a permanent tracheostomy in the hospital within 24 hours. Just because a physician exchanges an airway placed in the prehospital setting does not mean it is a bad airway. Nor are paramedics wrong when they place a surgical airway on a patient who is later successfully intubated by a physician. Once at the hospital physicians have access to other intubation procedures, including fiber-optic intubation, that they may use, which may not be available out of the hospital.

Be sure to communicate when a surgical cricothyrotomy is performed with a device without an inflatable cuff, because a definitive airway has not been placed. Without an inflatable cuff an airway does not protect against aspiration, and it can be difficult to deliver an adequate tidal volume. In these instances do not be surprised to see a more definitive airway placed in the emergency department. This will happen immediately whenever a needle cricothyrotomy is used, as the needle cricothyrotomy does not allow for effective ventilation.

Summary

Managing the airway does not mean intubation, it means managing the airway. Allowing a patient to breathe on their own with appropriate positioning, bag-valve ventilation and blind insertion devices are all airway management options. The surgical cricothyrotomy is a rare and life-saving procedure when managing patients who are in a “can’t intubate, can’t ventilate” situation. These patients will die without aggressive and rapid intervention. While not all surgical cricothyrotomies provide a definitive airway, the needle cricothyrotomy is an ineffective means for ventilation and its use is discouraged. Understand the techniques used in your program and that are within your scope of practice as an EMS provider. Provide your patient the best opportunity for survival by knowing your program’s surgical airway procedure thoroughly, and practice it regularly.

References

1. King DR, et al. Emergent cricothyroidotomies for trauma: training considerations. Am J Emerg Med, 2012; 30: 1429–1432.

2. Brown CA, et al. 4871 Emergency Airway Encounters by Air Medical Providers. Western J Emerg Med, 2014; 15(2): 188–193.

3. Jacobson LE, et al. Surgical Cricothyroidotomy in Trauma Patients: Analysis of Its Use by Paramedics in the Field. J of Trauma: Injury, Infection, and Critical Care, 1996; 41(1): 15–20.

4. Marx JA, Hockberger RS, Walls RM. “Airway.” In Rosen’s Emergency Medicine: Concepts and Clinical Practice, Vol 1., 6th ed. Philadelphia: Mosby Elsevier, 2006.

5. Strange GR, Niederman LG, Henretig FM, King C. “Surgical cricothyrotomy.” In Textbook of Pediatric Emergency Procedures. Baltimore: Williams & Wilkins, 1997, pp. 351.

6. Hubble M, at al. A Meta-analysis of prehospital airway control techniques part II: alternative airway devices and cricothyrotomy success rates. Prehospital Emergency Care, 2010; 14: 515–530.

7. Michalek-Sauberer A, et al. The Efficacy of Spontaneous and Controlled Ventilation with Various Cricothyrotomy Devices: A Quantitative In Vitro Assessment in a Model Lung. J Trauma, 2011; 71: 886–892.

8. Schaumann N, et al. Evaluation of Seldinger Technique in Emergency Cricothyroidotomy versus Standard Surgical Cricothyroidotomy in 200 Cadavers. Anesthesiology, 2005; 102(1); 7–11.

9. Smith M. Use of a gum elastic bougie during surgical crichothyrotomy. Am J Emerg Med, 2008; 26: 738.

10. Hubert V, et al. Effect of Simulation Training on Compliance with Difficult Airway Management Algorithms, Technical Ability, and Skills Retention for Emergency Cricothyrotomy. Anesthesiology, 2014; 120: 999–1008.