The following clinical scenario highlights the importance of upper airway point-of-care ultrasound (POCUS) in managing a patient in respiratory distress.
A 65-year-old male patient with a body mass index (BMI) 50 kg·m−² presented to the emergency department in respiratory distress with associated fever, severe sore throat, and drooling. He reported progressive dysphagia and difficult phonating over the past couple of days. The patient’s medical history was otherwise significant for hypertension, diabetes, and dyslipidemia. The patient was oxygenated with high-flow nasal cannula and immediately transferred to the operating room (OR) for an emergency intubation. Prior to airway management, neck landmarks were challenging to palpate on the thick neck, and ultrasonography of the upper airway was performed to identify swelling in the airway and to premark the cricothyroid membrane (CTM) location and its depth in preparation for a double set up with a front-of-neck airway (FONA). In the OR, the patient’s airway was topicalized with lidocaine, and an awake intubation was attempted with a flexible bronchoscope, which revealed an inflamed and erythematous epiglottis. The intubation attempt was unsuccessful, and the patient experienced a complete airway obstruction, losing consciousness shortly after. Without delay, a front-of-neck cricothyrotomy using a scalpel-bougie-tube was successfully performed. The patient was subsequently transferred to the intensive care unit (ICU) and underwent an ultrasound-guided percutaneous tracheotomy (PCT) the next day.
What Is the Role of POCUS in Surgical Cricothyrotomy?
The role of ultrasound for upper airway access has been described for a variety of procedures including endotracheal tube (ETT) placement, predicting difficult airways, and assessing airway anatomy and pathologies prior to surgical airway access.1–3 During instances of “cannot intubate, cannot oxygenate” (CICO), difficult airway guidelines recommend establishing a surgical airway. In emergency settings, cricothyrotomies are preferred to tracheotomies as they are faster and easier to perform.4,5 Successful cricothyrotomies are dependent on the rapid and accurate identification of the CTM. While POCUS has been described for assessment of the difficult airway, there is a relative paucity of literature regarding the use of ultrasound for CTM localization prior to cricothyrotomies. Location of the CTM by digital palpation (DP) has been shown to be challenging in emergency and nonemergency situations enhancing the risk of complications such as esophageal perforation, laryngeal trauma, and false passage cannulation.6–8 Ultrasound plays an important preprocedure role when a surgical airway is a material possibility when managing a difficult airway.
Is the Use of Ultrasound Justified in Locating the CTM in an Emergency?
The utility of ultrasound in identifying the CTM becomes more apparent in individuals with difficult neck anatomy. Ultrasound is noninvasive, can accurately identify the CTM and can be performed relatively quickly. An early study compared CTM identification with ultrasound and conventional DP in higher BMI patients.9 Investigators found that while increased BMI caused a significant ...