A 36-year-old man is rushed to the emergency department after sudden onset of shortness of breath and difficulty swallowing. He has visited the emergency department several times before due to food and skin allergies. The patient is unconscious on arrival. Examination shows excessive accessory respiratory muscle use and edematous swelling of the face, lips, and tongue. There is also scattered urticaria over the upper body. Attempts at intubation are unsuccessful due to massive soft tissue edema involving the pharynx. A decision is made to perform an emergency cricothyrotomy. The incisions made during this procedure will most likely pass through which of the following structures?
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This patient is experiencing acute, life-threatening laryngeal edema as part of an anaphylactic reaction precipitated by exposure to an allergen. Laryngeal edema can initially present with throat tightness, difficulty swallowing, dyspnea, and hoarseness. However, the condition can quickly progress to compromise the airway and cause asphyxiation.
Cricothyrotomy is indicated when an emergency airway is required and orotracheal or nasotracheal intubation is either unsuccessful or contraindicated (eg, massive hemorrhage, vomiting, facial trauma, airway obstruction). The procedure establishes an airway through the placement of a tube between the cricoid and thyroid cartilages and requires incision through the following structures:
(Choice A) The buccopharyngeal fascia invests the pharyngeal constrictor muscles and lies anterior to the alar fascia, forming the retropharyngeal space between them. The danger space lies posterior to the retropharyngeal space (between the alar and prevertebral fascia). Retropharyngeal abscesses can drain directly into the superior mediastinum or penetrate into the danger space to extend along the entire length of the mediastinum, causing acute necrotizing mediastinitis.
(Choices B and C) The cricoid cartilage lies inferior to the thyroid cartilage at the level of the C6 vertebra, and the thyroid isthmus lies inferior to the cricoid cartilage. Incisions made during cricothyrotomy should be performed with care to prevent damage to these structures.
(Choice D) The deep cervical fascia is composed of three layers: investing, pretracheal, and prevertebral. The prevertebral layer of the deep fascia surrounds the vertebral column and spinal muscles; it is not penetrated during cricothyrotomy.
Educational objective:
Cricothyrotomy is indicated when an emergency airway is required and orotracheal or nasotracheal intubation is either unsuccessful or contraindicated. The cricothyrotomy incision passes through the superficial cervical fascia, pretracheal fascia, and the cricothyroid membrane.