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Epiglottitis
Background
Epiglottitis, also known as supraglottitis, is an acute, severe, life-threatening disease of the upper airway. First described in 1878, it was thought to be a disease of adults. It is now thought to be a disease predominately of children, although that, also, is changing. The spectrum of this disease has gone through significant changes since the introduction of the Haemophilus influenzae type B (HIB) vaccine in 1985. This disease had occurred most frequently in children aged 2-7 years and most commonly was caused by HIB. Many other pathogens exist which can cause epiglottitis (group A, B, and C Streptococcus, Streptococcus pneumoniae, Klebsiella pneumoniae, Candida albicans, Staphylococcus aureus, Haemophilus parainfluenza, Neisseria meningitidis, varicella zoster, and several other viruses). Direct trauma and thermal injury also can cause inflammation of the epiglottis. The emergency physician is less likely to see this disease in its traditional presentation. Previously, the emergency physician quickly recognized this disease. With decreasing frequency and variable presentation, this may no longer be the case.
Pathophysiology
As mentioned, epiglottitis most frequently is caused by H influenzae . Although overall incidence of epiglottitis is dropping, H influenzae is still the most common cause. Vaccination only prevents typeable H influenzae . Nontypeable H influenzae rarely can cause epiglottitis. Recently, group A beta-hemolytic Streptococcus (GABHS) has been on the increase, but the sample sizes are too small to say a definite change is occurring. In most cases, invasive H influenzae disease is secondary to a bacteremia. In epiglottitis, usually a local invasion of the epiglottis occurs followed by bacteremia. The epiglottis, aryepiglottic folds, false vocal cords, and supraglottic structures become inflamed and edematous, leading to narrowed airway and respiratory compromise. Inspiratory airway occlusion often occurs prior to total occlusion from supraglottic edema.
Other infectious agents may have a different clinical course, and the affected structures may vary with the infecting organism. A recent report of a child with group A streptococcal epiglottitis described the child's aryepiglottic folds as more involved than the epiglottis. GABHS has been described causing epiglottitis in a child with varicella.
Children who ingest hot liquids may develop symptoms of epiglottitis. Children with scald burns to the face should be observed carefully for this complication. Other causes of an epiglottitislike presentation include caustic ingestions, foreign bodies, inhalation injuries, angioneurotic edema, sidestream exposure to crack cocaine, and burns from a crack cocaine pipe screen filter.
Frequency
- In the US : The prevalence of epiglottitis has shown a dramatic decline since the introduction of the HIB vaccine. Recent epidemiological studies show a decreased incidence in children from 3.47 cases per 100,000 people in 1980 to 0.63 cases per 100,000 people in 1990. A study published in 1994 showed a decrease in hospital admissions for epiglottitis from 10.9 per 10,000 people before 1990 to 1.8 per 10,000 from 1992-1994. Incidence is decreasing in all age ranges, even in adults that have not received the HIB vaccine. This is thought to be because of the decrease in HIB disease in the general population.
- Internationally: Prevalence varies widely by geographic location. Various reports have shown an incidence of 6 cases per 100,000 people in Quebec , Canada ; 14 cases per 100,000 people in Stockholm , Sweden ; and 34 cases per 100,000 people in Geneva , Switzerland .
Mortality/Morbidity
Reports of morbidity and mortality rates vary, depending on time to diagnosis, interventions employed, and use of an established protocol. In centers with pediatric expertise and defined protocols, the mortality rate approaches zero and the morbidity rate less than 4%. Delay in diagnosis is associated with a 9-18% mortality rate. Management of patients without intubation is associated with a 6% mortality rate.
Race
One recent multicenter study demonstrated predominance in blacks and Hispanics. This may represent vaccination status differences. Previous studies have not addressed racial differences.
Sex
Most studies show a 60% male predominance. This has remained true even with the changing epidemiology of epiglottitis.
Age
Epiglottitis traditionally has been most frequent in children aged 3-7 years. During the past 13 years, the median age in the US has increased from 35 months to 80 months. The disease can, however, occur at any age, from the newborn period to adulthood. Prevalence in adults now surpasses prevalence in pediatrics due to success of the HIB vaccination.
History
The classic presentation is a young child who develops a fever and may complain of sore throat. The child may refuse to eat. Over a matter of hours, the child is unable to tolerate even his own secretions and begins to drool. The child develops signs of upper airway obstruction with stridor and a varying degree of respiratory compromise. The older child will sit with his neck extended in the sniffing position.
- Older children may present with a more prolonged prodrome and with more subtle findings. Also, agents other than HIB may present differently.
- The clinical triad of drooling, dysphagia, and distress is the classic presentation. Fever with associated respiratory distress or air hunger occurs in most patients. Drooling occurs in up to 80% of cases.
- The child also has a muffled voice.
- Age of patient, prodrome, type of cough, and degree of toxicity can all contribute to differentiation of epiglottitis from severe croup. Usually, croup occurs in younger children and has a viral prodrome. Most importantly, the child with croup has a barking cough and rarely appears toxic.
Physical
- The child is febrile and appears toxic or anxious.
- The older child assumes a characteristic tripod posture with the neck extended.
- Stridor frequently is present.
- As the child cannot tolerate secretions, drooling frequently is present.
- Cough is rare.
Causes
- Historically, HIB was the predominant organism.
- The HIB vaccine has decreased the number of cases due to infection with this organism.
- Recent reports have shown that even vaccinated children can develop epiglottitis from H influenzae .
- S aureus
- S pneumoniae
- C albicans
- Several viruses
- Traumatic epiglottitis can occur from direct trauma and thermal injury.
Lab Studies
- Securing an airway is the overriding priority. All further evaluations should follow.
- Blood cultures and culture of the epiglottis should be performed only after the airway is secured.
- Leukocytosis with a left shift is common.
Imaging Studies
- Soft tissue lateral neck radiographs may be obtained in uncertain cases but should not delay definitive treatment. An enlarged epiglottis with a "thumbprint" sign is the classic described finding.
- The child must be monitored closely and accompanied by staff members who are able to secure an immediate airway.
- For potentially unstable patients, such films should be performed at the child's bedside in the upright sitting (not supine) position. (Supination has been reported to lead to respiratory arrest.)
- After intubation, a chest radiograph is obtained to ensure appropriate placement.
Other Tests
- Blood cultures and cultures of the epiglottis should be obtained after the airway is secured.
- Blood cultures are positive in more than 80% of cases caused by H influenzae.
- Epiglottic cultures are positive in 50% of cases caused by H influenzae.
Prehospital Care
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Immediate transport to the nearest appropriate facility is necessary (emergency department approved for pediatrics [EDAP] or pediatric critical care center [PCCC]).
- Obtaining vital signs or any other diagnostic procedures are secondary to securing the airway.
- The child should be allowed to assume a position of comfort. The parent should be allowed to hold the child.
- Oxygen may be administered if it does not disturb the child.
- If the child has a respiratory arrest, first attempt ventilation with a bag-valve mask. Long, slow ventilations are best.
- Orotracheal intubation should be attempted if unable to ventilate the child. Needle cricothyroidotomy is used only if unable to secure an airway.
- If the child is to be transported to another facility, the airway should be secured. Only then should an IV line be placed. The child should be sedated and given antibiotics prior to transfer.
Emergency Department Care
- As previously discussed, securing an airway is the first priority. Staff capable of intubation or tracheostomy should accompany the child at all times. Nonblind, fiberoptic-assisted, nasotracheal intubation under controlled conditions is preferred.
- The patient should be allowed to sit upright during the procedure.
- Orotracheal intubation or needle cricothyroidotomy may be necessary in emergent situations.
- Pediatric epiglottis is one of the few instances in which the emergency physician may need to rapidly perform needle cricothyrotomy.
- Most physicians are not aware that normal, volume-controlled, oxygen wall ports are incapable of delivering the pressure needed to adequately oxygenate an adult through a 14-g catheter (50 psi).
- In some trauma centers, needle jet setups specifically are preinstalled to address this concern, with a pressure-controlled port (instead of the volume-controlled port).
- For children, a setting of 1 psi/kg is recommended, although literature is lacking.
- Transtracheal jet insufflation does little for ventilation; however, it may salvage enough time in cases of complete inspiratory airway occlusion to perform tracheostomy or begin extracorporeal bypass maneuvers.
- Lateral neck radiographs may be obtained in uncertain cases, but the child must be closely monitored.
- Direct visualization of the epiglottis should not be performed unless staff members capable of securing an airway are present.
- Establishing an IV line, obtaining cultures, and administering antibiotics and sedation should follow securing an airway.
- Currently, no controlled studies exist on the use of IV steroids for reduction of airway structure edema due to pediatric epiglottitis. Nonetheless, some clinicians routinely use them in cases with adults.
- Despite evidence of an increased morbidity and mortality in patients treated without intubation, reports of children managed on an observation basis have been reported. Some reports have been made of cases managed on an outpatient basis. Patients managed successfully with observation were generally older and able to tolerate their secretions. This approach should be used with caution.
Consultations
- Immediate consultation with a specialist capable of performing a tracheostomy is required.
- As the child should be admitted to an intensive care unit, the intensivist must be consulted.
Further Inpatient Care
- Most children require sedation to avoid accidental extubation.
Transfer
- If the hospital is unable to care for critically ill children, transfer should be arranged to the nearest appropriate facility, which, ideally, would be a hospital with a pediatric intensive care unit.
Deterrence/Prevention
- As mentioned earlier, the HIB vaccine has dramatically reduced the incidence of epiglottitis. This vaccine is recommended for all children. Epiglottitis can still occur in children who are completely vaccinated. Households with at least one unvaccinated child younger than 4 years and proven H influenzae epiglottitis should be considered for prophylaxis with rifampin.
- As other infectious agents can cause epiglottitis, refer to prophylaxis for those agents. Specific recommendations can be found in the American Academy of Pediatrics "Report of the Committee on Infectious Diseases."
Complications
- During the bacteremic phase of the disease, other foci of infection are possible. Pneumonia is the most commonly cited associated illness, with otitis media being the second. Meningitis has been reported in association with epiglottitis.
- As with other causes of upper airway obstruction, pulmonary edema can be observed after the airway has been secured. Accidental extubation and respiratory arrest are the 2 most common complications.
- Accidental extubation can cause additional complications.
Prognosis:
- Once the airway has been secured, prognosis is excellent with mortality rate falling below 1%.
Medical/Legal Pitfalls
- If epiglottitis is suspected, immediate assembly of a team capable of securing a protected airway is the utmost priority.
- Never leave the child unaccompanied.
- No diagnostic tests are required before taking the child to the operating room.
- Direct visualization of the epiglottis in the ED is unwise, although, in reality, no cases of laryngospasm due to such visualization have ever been reported in the literature.
- As the disease becomes more rare, its existence and its quick progression may be forgotten.
- A written protocol should be available for a child presenting with possible epiglottitis.
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