Approach Considerations
Airway management is the most urgent consideration, and patients should first be assessed for level of distress before any other workup. Adults generally present in a less acute fashion than children. [4] Ensure that an anesthesiologist and an otolaryngologist are available. Patients may deteriorate precipitously, and airway equipment, including that for cricothyrotomy, should be present at the patient's bedside. Some authors have attempted to grade degrees of epiglottitis severity to guide treatment, and this is a practical approach.
Radiographic evaluation for suspected epiglottitis is being replaced by direct visualization of the epiglottis using nasopharyngoscopy/laryngoscopy as the preferred method of diagnosis. Only 79% of epiglottis cases are diagnosed by neck soft-tissue radiographs, underscoring the importance of direct visualization by fiberoptic endoscopy in obtaining a timely and accurate diagnosis.
Unstable patients
A patient in extremis requires immediate airway management. Signs and symptoms associated with a need for intubation include respiratory distress, airway compromise on examination, stridor, inability to swallow, drooling, sitting erect, and deterioration within 8-12 hours. Enlarged epiglottis (thumb sign) on radiographs is associated with airway obstruction. When in doubt, securing the airway is likely the safest approach.
Intubation, or immediate formal tracheostomy or cricothyrotomy, may be performed in the operating room. Needle-jet insufflation (also known as percutaneous transtracheal jet ventilation [PTJV]) may be considered to ventilate the patient temporarily. [5]
In cases of initial failure to intubate by direct laryngoscopy, PTJV may facilitate success in subsequent attempts at tracheal intubation by direct laryngoscopy. PTJV can produce high intratracheal pressures that appear to lift up and open the glottis, with escape of the pressurized gasses causing the glottis edges to flutter, thereby allowing improved identification of the glottic aperture.
Stable patients
Patients without signs of airway compromise, respiratory difficulty, stridor, or drooling, and those who have only mild swelling on laryngoscopy, may be managed without immediate airway intervention by close monitoring in the intensive care unit (ICU). Because of the rapidity with which airway obstruction can occur in these patients, repeat serial evaluations of airway patency and maintenance of a low clinical threshold for airway placement are indicated.
Laryngoscopy is recommended before extubation. An ear, nose, and throat (ENT) specialist and an anesthesiologist should be immediately available at all times.
Nasopharyngoscopy/Laryngoscopy
Direct visualization of the epiglottis using nasopharyngoscopy/laryngoscopy is the preferred method of diagnosis and is replacing radiographic evaluation for suspected epiglottitis. The airway should be secured or should be readily securable if endoscopy is performed.
Radiography
Avoid radiography for patients who present in extremis until the airway is secure due to the danger of sudden obstruction.
Radiographs are generally unnecessary when the diagnosis can be made by history and physical examination alone or with nasopharyngoscopy. Only 79% of epiglottis cases are diagnosed using neck soft-tissue radiographs. Bedside ultrasonography is rapid, noninvasive, and accurate in the hands of a practitioner experienced in its use. [21]
Lateral neck soft-tissue radiography
Most adults are not in extremis and may safely undergo imaging. In evaluating stable patients with suspected epiglottitis, lateral neck soft-tissue radiographs are useful screening tools. Perform radiography with portable equipment, if indicated; this may confirm the diagnosis.
The classic lateral neck radiographic findings are a swollen epiglottis (ie, a thumb sign), thickened aryepiglottic folds, and obliteration of the vallecula (vallecula sign). See the image below.
Soft-tissue lateral neck radiograph reveals edema of epiglottis consistent with acute epiglottitis.
The epiglottis is usually 3-5 mm thick; in a small, retrospective study of 30 patients with epiglottitis, using a criterion of 7-mm thickness provided 100% sensitivity and specificity for adult acute epiglottitis. [22] The same small retrospective study yielded 83% sensitivity and 100% specificity for an aryepiglottic fold width greater than 4.5 mm. [22]
Another useful tool in differentiating epiglottitis is to examine the vallecula (pre-epiglottic space). To locate the vallecula, use a soft-tissue lateral neck radiograph taken while the patient's mouth is closed. The vallecula is the air pocket found at the level of the hyoid bone just anterior to the epiglottis. The vallecula is normally well delineated, deep, and roughly perpendicular to the pharyngotracheal air column. The "vallecula sign of epiglottitis" is present when the normal deep linear air space from the tongue base almost to the epiglottis is made shallow or obliterated. Instead of a deep linear space, a V-shaped shallow space is seen. [23]
Chest radiography
Avoid radiography until the patient's airway is secure. Obtain a chest radiograph (CXR) to assess endotracheal tube (ET) placement. The chest radiograph may reveal pneumonia.
Ultrasonography
Initial studies regarding the applicability of using bedside ultrasonography in the evaluation of the normal epiglottis found it to be both easy to perform and accurate. [24] More recently, Prasad et al suggested complementing a sublingual scanning approach with a transcutaneous approach. [25] Further analysis regarding usage of bedside ultrasonography in evaluating epiglottic disease and pathologic epiglottic enlargement may help determine the future clinical role of ultrasonography in the management of acute epiglottitis.
Microbiology
Blood cultures may be taken, particularly if the patient is systemically unwell. The cultures are positive in approximately 25% of adult cases. Given the relatively large number of infectious agents besides H influenzae type b and Streptococcus species that may cause adult epiglottitis, blood culture and sensitivities may be particularly helpful in this population.
In adults with acute epiglottitis, blood cultures for Haemophilus influenzae are positive in about 25% of cases. In remaining adult cases, H parainfluenzae, Streptococcus pneumoniae, and group A streptococci are frequently isolated from pharyngeal cultures.
If the airway is secure, epiglottic cultures may be performed. Some authors have described successful aspiration of epiglottic abscesses via spinal needle. [26]
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Soft-tissue lateral neck radiograph reveals edema of epiglottis consistent with acute epiglottitis.
