emDOCs Podcast – Episode 64: Epiglottitis

Today on the emDOCs cast with Brit Long, MD (@long_brit), we cover epiglottitis.

Episode 64: Epiglottitis

Epidemiology:

• Steadily increasing with an incidence of 1/100,000 to 4/100,000 in the U.S. in adults
• Pediatric incidence has decreased to 0.5/100,000
  • Previously more common in unvaccinated children, but now more common in adults
• Life-threatening infection of epiglottis
  • Occurs via direct invasion of the epithelial layer by the organism or by bacteremia
    • Bacteremia more commonly associated with pediatric epiglottitis, though does not correlate to the severity of infection
  • Edema and inflammatory cell accumulation in the potential space between the epiglottic cartilage and epithelial layer, resulting in swelling of the epiglottis and supraglottic structures
• Often bacterial though can occur via viral or fungal infection, foreign body ingestion, thermal injury, lymphoproliferative disease or graft-versus-host disease, chronic granulomatous diseases, and caustic ingestions.

Microbiology:

• Often polymicrobial, and predominant bacteria include:
  • Streptococcus pyogenes (group A strep), Staphylococcus aureus (MSSA, MRSA)
  • Pseudomonas aeruginosa should be considered in immunocompromised patients

Evaluation:

• Adult and pediatric patients often differ in presentation.
• Pediatric patients present more common with a sudden decompensation, evidence of respiratory distress/tripod position
• Adult patients present with:
  • 90-100% with odynophagia
  • 85% with dysphagia
  • 74% with voice changes
  • Tripod positioning less common in adults due to larger airway caliber, occurring in less than 50% of adult patients
  • Voice change
  • Retractions
• Rapid onset of symptoms within 12-24 hours is a harbinger of severe disease, though adults usually present in subacute fashion

Examination:

• 90% of patients with epiglottitis with have a normal oropharyngeal exam
• Fever in 26-90%
• Muffled voiced in 50-65%
• Difficulty handling secretions 50-80%
• Cervical lymphadenopathy
• Severe pain with palpation of the external larynx or hyoid bone
• Direct visualization of the epiglottis with nebulized lidocaine
  • Clinician should face the patient and places the Macintosh blade onto patient’s tongue.
  • Ask patient to speak in a high-pitched tone, raising the supraglottic structures several centimeters for potential visualization

Laboratory analysis:

• Limited utility since clinical diagnosis:
  • Cultures
    • Blood: 0-17% yield
    • Throat: 10-33% yield
    • Epiglottis: 75% yield
  • Dehydration due to odynophagia may be present, resulting in renal injury, electrolyte abnormalities

Imaging:

• Upright lateral neck radiograph
  • Thumbprint sign: epiglottic swelling with a sensitivity of 89.2% and specificity of 92.2%
  • Vallecula sign: normal deep linear air space from the base of the tongue to the epiglottis is shallow or absent
  • Epiglottic width greater than 6.3 mm demonstrates has a sensitivity of 75.8% and a specificity of 97.8%.
  • False negative rate of 31.9% so negative radiograph does not rule out diagnosis
• Computed Tomography (CT) with contrast of the neck
  • Requires patient to lay supine
    • May aggravate impending airway occlusion
  • Sensitivity of 88-100% and specificity of 97-96%
  • Can show:
    • Effusion
    • Obliteration of surrounding fat planes
    • Thickening of false vocal cords
    • Retropharyngeal enhancement and edema
    • Epiglottic abscess: Associated with a high likelihood of requiring airway
•  Point of care ultrasound
  • Allows for evaluation in position of comfort
  • Increased anteroposterior diameter of the midpoint and lateral epiglottis associated with epiglottitis
  • Alphabet P sign is also suggestive of epiglottitis
    • hypoechogenicity on a longitudinal view at the thyrohyoid membrane level
  • Direct visualization of epiglottis confirms diagnosis—set up for therapeutic intervention simultaneously

Management:

• Position of optimal patient comfort is key
• Airway management
  • Intubation with flexible intubating endoscopy is the method of choice
  • Intubation occurs in epiglottitis patients in 13.2% of cases
  • Video laryngoscopy is used less commonly but is also an option
  • Do not use supraglottic devices; may not seat well and may cause airway occlusion
  • Factors associated with increased likelihood of intubation:
    • Historical factors: Diabetes mellitus, subjective dyspnea, rapid symptom progression over 12-24 hours, stridor,
    • Objective measures: 20 breaths per minute with subjective complaint of dyspnea required visualization of the airway, while a respiratory rate greater than 30 breaths per minute, hypercarbia (PCO₂ greater than 45 mm Hg)
•   Antibiotics:
  • Ceftriaxone 2g intravenous (IV) or ampicillin-sulbactam 3g IV with vancomycin 20 mg/kg IV for methicillin resistant Staphylococcus aureus (MRSA) coverage
  • Severe penicillin allergy: levofloxacin 750 mg IV
  • Immunocompromised: cefepime 2g IV is recommended for P. aeruginosa coverage
• Corticosteroids are controversial though between 20-83% will receive corticosteroids
  • Have not demonstrated any improvement in ICU length of stay, hospital length of stay, or duration of intubation
• Nebulized epinephrine may help temporize airway by assisting with bronchodilation
  • Do not use in children
    • Generates additional agitation, laryngospasm, and rapid deterioration with no benefit in the literature

Pearls:

• More common in adults who present with odynophagia, dysphagia, and over a more subacute time frame
• Normal oropharynx occurs in 90% of adults with epiglottitis
• Lateral neck radiographs are a screening tool which may show the thumbprint or vallecula sign though have a high false positive rate
• Factors associated with increased rates of intubation are diabetes mellitus, symptoms over 12-24 hours, stridor, drooling, tachypnea, hypercarbia, epiglottic abscess, and subglottic extension
• Airway management has shifted from intubation/surgical airway in the operating room to awake fiberoptic intubation
• Corticosteroids and nebulized epinephrine may assist in decompensating patients, but the literature is controversial

References:

• Bridwell RE, Koyfman A, Long B. High risk and low prevalence diseases: Adult epiglottitis. Am J Emerg Med. 2022 Jul;57:14-20.