a blog series on emergency medicine procedures
In the last post (the cricothyrotomy part 1) we focused on the basics of preparation and technique for the cricothyrotomy procedure. Here we focus on the pearls, pitfalls, and troubleshooting with a strong emphasis on anatomy.
As an aside…
Always consider alternatives to the cricothyrotomy, and especially, the “crash” cricothyrotomy
Try other non-invasive rescue maneuvers including the intubating LMA as Dr. Nestor mentioned last week
Review the difficult airway algorithms that were briefly acknowledged last week, and strive for expertise in airway decision-making
Do not hesitate to overhead anesthesia for assistance in any difficult airway
Avoid paralyzing patients with tenuous airways in appropriate situations, and consider awake (fiberoptic or other) intubation, or even awake cricothyrotomy with ketamine (and local anesthetic)
PEARL #1: KNOW YOUR ANATOMY…
Why is this so important? First let’s explore some potential pitfalls….
PITFALL: You make your vertical incision OFF midline
- You may not find the membrane
- Complications: you may injure the following structures:
- Cricothyroid muscles
- Recurrent laryngeal nerves (uncommon)
- Carotid artery / Internal Jugular vein (very rare)
PITFALL: You make a horizontal cut too SUPERIOR
- Superior to cricothyroid membrane:
- This is above the cords, and likely the location of your issue (i.e.: obstruction or other)
- Complications: increased risk of vascular and nerve damage: superior laryngeal vessels and the internal branch of the superior laryngeal nerve
PITFALL: You make a horizontal cut too INFERIOR
- This is a tracheostomy: an airway for a surgeon. If avoidable, this should not be done in a crash setting
- The tracheal rings do not have a posterior shell (like the cricoid), which theoretically increases the risk of perforating esophagus
- Complications: Damage to trachea, esophagus, and increased risk of vascular and nerve damage (also, thyroid gland)
- Caveat: for distorted anterior neck trauma that needs an airway, directly enter the wound if there are no other options (best done by most experienced trauma surgeon)
PITFALL: You rely wholly on visualization of the cricothyroid membrane
- At minimum, this procedure is highly dependent on palpation of anatomy
- There will be blood
- Do not attempt to obtain hemostasis until after your tube is in
- NOTE: Finding and marking the membrane is even difficult with palpation (compared to ultrasound) in a small study on the percutaneous needle method (1)
Back to PEARL #1: KNOW YOUR ANATOMY…the most reliable way to avoid the aforementioned catastrophes…
The cricothyroid membrane: elastic, subcutaneous, triangular, ~9mm (vertical) x ~30mm (horizontal), anterior midline of the neck, relatively avascular, and finally, below the level of the vocal cords
From Netter’s Atlas of Human Anatomy, 4th ed, 2006
WATCH THIS VIDEO NOW.
From Andy Neill’s Emergency Medicine Ireland, Anatomy for Emergency Medicine 07: Cricothyroidotomy
PEARL: Finding the cricothyroid membrane
- Palpate just inferior to the laryngeal prominence (Adam’s apple)
- Use the Laryngeal Handshake (Levitan, R)
TROUBLESHOOTING: You still cannot find the cricothyroid membrane
- Remember to hyperextend the neck, if not contraindicated (i.e.: trauma)
- Patient with obesity, or massive neck swelling?
- Stay midline throughout this process!
- Extend your vertical incision (superior and inferior) and blunt dissect deeper
- Stay midline throughout this process!
PEARL: the BORDERS of the cricothyroid membrane consist of CARTILAGE in all directions
- Superior: thyroid cartilage and laryngeal prominence (Adam’s apple)
- Inferior and posterior: cricoid cartilage
- Lateral: cricoid and thyroid cartilage (and cricothyroid muscles)
PEARL: How to avoid the cricothyroid artery
- It may help to make the horizontal cut at the most inferior end of the cricothyroid membrane to avoid hitting the small cricothyroid artery
- If you hit this artery, ignore the blood, re-palpate landmarks, and complete the procedure. After airway is secured, ligate this small vessel
TROUBLESHOOTING: You encounter resistance and cannot pass the tube
- Make sure you are not in a peri-tracheal space. Quickly remove and replace!
- Complications: subcutaneous and mediastinal emphysema, cardiac arrest from respiratory failure (time wasted)
- How to avoid: use your obturator, or use the scalpel-finger-bougie method
TROUBLESHOOTING: You are sterile and ready to perform the cricothyrotomy, but neither you or anyone else can find the tracheostomy tube
Modify a 6.0 endotracheal tube.
From Roberts & Hedges’ Clinical Procedures in Emergency Medicine, 6th ed, 2013
- 6mm ETT is preferred for ease of passage via the small cricothyroid membrane. Never > 7mm. Same for tracheostomy tubes.
- Modified = shortened = cut the tube (PROXIMAL TO THE INFLATION DEVICE) and reattach the end portion = decreases risk of kinked tube
- Use a bougie and advance both ETT and bougie ONLY ~5cm from their tips to avoid mainstem intubation. Listen to both lungs immediately after. By delivering air to only 1 lung – barotrauma – tension pneumothorax (2)
- NOTE: exchange the ETT for a tracheostomy tube over bougie ASAP
UP NEXT…PEDIATRIC POINTS ON THE CRICOTHYROTOMY… CLICK HERE
PLEASE SHARE ANY OF YOUR OWN PEARLS, PITFALLS, AND TROUBLESHOOTING ON THE CRICOTHYROTOMY IN THE COMMENTS SECTION
Hebert R, Bose S, Mace. Cricothyrotomy and Percutaneous Translaryngeal Ventilation. Chapter 6, 120-133.e2. In: Roberts J, et al. Roberts & Hedges’ Clinical Procedures in Emergency Medicine. 6th Saunders; 2013
- Elliott DS, Baker PA, Scott MR, Birch CW, Thompson JM. Accuracy of surface landmark identification for cannula cricothyroidotomy. Anaesthesia. 2010 Sep;65(9):889-94. PubMed PMID: 20645953
- Engoren M, de St Victor P. Tension pneumothorax and contralateral presumed pneumothorax from endobronchial intubation via cricothyroidotomy. Chest. 2000 Dec;118(6):1833-5. PubMed PMID: 11115485
Netter, F. Thyroid Gland and Larynx. Section 1, Head and Neck, Plates 74-80. In: Netter, F. Atlas of Human Anatomy. 4th Edition. Saunders; 2006.