Usage of airway ultrasound as an assessment and prediction tool of a difficult airway management.

Airway assessment is important in emergency airway management. A difficult airway can lead to life-threatening complications. A perfect airway assessment tool does not exist and unanticipated difficulty will remain unforeseen. Current bedside clinical predictors of the difficult airway are unreliable but airway ultrasound can be used as an adjunct to predict difficult laryngoscopy. We report a case of a 60-year-old man presenting to the emergency department with shortness of breath, hoarseness of voice and stridor. Airway ultrasound revealed a large laryngeal mass narrowing the upper airway, extending to bilateral vocal cords with heterogenous echogenicity. In view of impending complete upper airway obstruction, acute respiratory distress and airway ultrasound findings, urgent emergency tracheostomy was chosen as definitive airway over endotracheal intubation or surgical cricothyroidotomy. Point of care ultrasound (POCUS) was used to evaluate this patient with severe upper airway obstruction. A laryngeal mass was detected by ultrasound and this pointed towards the presence of a difficult airway. POCUS was a good non-invasive tool used for airway assessment in this uncooperative and unstable patient. Ultrasound predictors of the difficult airway include the inability to visualize the hyoid bone, short hyomental distance ratio, high pretracheal anterior neck thickness and large tongue size. Besides airway assessment, ultrasound can also help to predict endotracheal tube size, confirm intubation and guide emergency airway procedures such as cricothyroidotomy and tracheostomy. Point of care ultrasound of the upper airway can be used in airway assessment to identify distorted airway anatomy, pathological lesions and guide treatment decisions.

Assessment of computed tomography derived cricoid cartilage and tracheal dimensions to evaluate degree of cricoid narrowing in brachycephalic dogs.

The aims of this observational, analytical, retrospective study were to (i) obtain computed tomographic (CT) cricoid dimensions (height, width, and transverse-sectional area), (ii) compare the cricoid dimensions between brachycephalic and mesaticephalic breeds, and (iii) compare cricoid cartilage dimensions between dogs without and affected with brachycephalic airway syndrome. The study is important to help to further evaluate and understand the anatomical components of brachycephalic airway syndrome. Measurements were performed in 147 brachycephalic and 59 mesaticephalic dogs. The cricoid cartilage was found to be significantly more oval in Pugs and French Bulldogs compared to mesaticephalic breeds. The cricoid cartilage transverse-sectional area was smallest for the Pug and, after adjusting for weight, significantly smaller for Pugs (P < 0.001), Boston Terriers (P = 0.001), and French Bulldogs (P < 0.001) compared to Jack Russell Terriers. The tracheal transverse-sectional area at C4 of English Bulldogs was significantly smaller than for Jack Russell Terriers (P = 0.005) and Labradors (P < 0.001). The cricoid cartilage transverse-sectional area:weight ratio was significantly lower in brachycephalic breeds compared to mesaticephalic breeds (P < 0.001). The cricoid cartilage:trachea at C4 transverse-sectional area for brachycephalic dogs was significantly larger than for mesaticephalic dogs (<0.001), demonstrating that the trachea was the narrowest part of the airway. No significant differences were found for cricoid dimensions between dogs affected with and without brachycephalic airway syndrome. However, large individual variation was found among the brachycephalic breeds and further studies investigating the relationship between cricoid cartilage size, laryngeal collapse, concurrent tracheal hypoplasia, and/or severity of brachycephalic airway syndrome are warranted.

Cricoarytenoiditis: CT assessment in rheumatoid arthritis.

The cricoarytenoid (CA) joint is a true diarthrodial joint that can be affected by rheumatoid disease. Its strategic location in the airway anatomy makes its evaluation of clinical importance. Direct fiberoptic laryngoscopy (DFL) and high-resolution computerized tomography (HRCT) were used to assess the larynx in 32 rheumatoid patients. Abnormalities were seen in 75% of patients at endoscopic examination. HRCT studies showed abnormalities in 72%. Erosion-luxation of the CA joint and surrounding soft-tissue swelling can be demonstrated on HRCT scans. A radiologic grading of the rheumatoid larynx is proposed, stressing that accurate evaluation of the larynx should be part of the diagnostic evaluation of every rheumatoid arthritic patient, given the high frequency of occurrence of rheumatoid laryngitis.