Tests
1st tests to order
laryngoscopy
Test
Direct (rigid or flexible) laryngoscopy can be performed. It is the key to confirming diagnosis, but is also therapeutic, as an airway can be established in the same setting if a direct laryngoscopy commences. This should be performed in the operating room, as an emergency surgical airway can be obtained if endotracheal intubation is not possible.
Result
swelling of supraglottic structures
erect lateral neck radiograph
Test
Classically referred to as a high-kilovoltage lateral neck radiograph.
Only to be obtained with healthcare professionals capable of securing the airway with proper equipment available during the test. The patient should be kept in an upright position. The child should not be sent to the radiology department unaccompanied for this examination. Also, the patient should not be perturbed, especially if it is a child. It is usually safe to perform this test in adults who are not in extremis.[Figure caption and citation for the preceding image starts]: Lateral neck film demonstrating thumbprint sign (arrows)From the collection of Dr Petri [Citation ends].
Result
markedly enlarged epiglottis, referred to as a "thumbprint sign"
Tests to consider
complete blood count
Test
Result
leukocytosis with left shift is possible
cultures of blood/supraglottis (epiglottis)
Test
Blood cultures and cultures from the supraglottis or epiglottis are critical in identifying the infecting organism, but should only be taken if possible and permissible without perturbing the patient and/or once the airway has been secured.
Result
positive cultures
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