Anatomy Pelvis Head Neck · Year 1 · from Anatomy Pelvis Head Neck
Case 3: Emergency Cricothyrotomy for Complete Upper Airway Obstruction
Patient Demographics
- Age: 45 years old
- Sex: Male
- Occupation: Chef
Chief Complaint
Sudden onset of severe throat swelling and inability to breathe.
History of Present Illness
The patient has a known history of angiotensin-converting enzyme (ACE) inhibitor use for hypertension. He was eating dinner at a restaurant when he suddenly developed progressive swelling of his tongue and lips. Despite administration of epinephrine and diphenhydramine by paramedics, his airway obstruction worsened. He became unable to speak and developed stridor, then complete airway obstruction. Multiple attempts at endotracheal intubation were unsuccessful due to massive tongue and pharyngeal edema.
Physical Examination
- Vitals (pre-arrest): HR 140 bpm, BP undetectable, RR agonal, SpO2 undetectable
- General: Unresponsive, cyanotic, massive facial and oral edema
- Airway: Complete obstruction, bag-mask ventilation ineffective
- Neck: Landmarks identifiable; thyroid cartilage and cricoid cartilage palpable
Procedure
Given failed intubation and inability to ventilate, emergency surgical cricothyrotomy was performed. The cricothyroid membrane was identified between the thyroid cartilage superiorly and the cricoid cartilage inferiorly. A horizontal stab incision was made through the membrane, the scalpel handle was used to dilate the opening, and a 6.0 cuffed tracheostomy tube was inserted. Immediate return of ventilation was achieved with SpO2 rising to 96%.
Clinical Image
Anatomical illustration demonstrating the location of the cricothyroid membrane between the thyroid and cricoid cartilages, the site for emergency surgical airway access.
Image Source: Wikimedia Commons - Larynx anatomy, Creative Commons Attribution-Share Alike 3.0
Diagnosis
ACE inhibitor-induced angioedema with complete upper airway obstruction requiring emergency surgical airway.
Anatomical Correlation
The cricothyroid membrane is the preferred site for emergency surgical airway access because it is superficial, avascular, and provides direct access to the airway. It lies between the inferior border of the thyroid cartilage and the superior border of the cricoid cartilage, measuring approximately 9 mm in height and 30 mm in width. The membrane is covered only by skin, subcutaneous tissue, and the investing layer of deep cervical fascia. The superior and inferior cricothyroid arteries (branches of the superior thyroid artery) anastomose across the upper portion of the membrane, so the incision is made in the lower third of the membrane to minimize bleeding. The cricothyroid membrane is located at the level of C5-C6. Landmarks are identified by palpating the laryngeal prominence (Adam's apple), sliding inferiorly over the thyroid cartilage to the gap above the cricoid cartilage. This procedure is preferred over tracheostomy in emergencies because it is faster and more superficial, though tracheostomy is preferred for long-term airway management.
Treatment
- Emergency cricothyrotomy: Immediate airway access
- Convert to formal tracheostomy: Once stabilized, typically within 72 hours
- ICU monitoring: Continued airway management and edema resolution
- Medication management: Discontinue ACE inhibitor permanently; substitute alternative antihypertensive
- Allergy documentation: Ensure ACE inhibitor allergy prominently documented