Membranous (Bacterial) TracheitisClinical SummaryMembranous tracheitis is an acute bacterial infection (Staphylococcus aureus, Haemophilus influenzae,streptococci, and pneumococci) of the upper airway capable of causing life-threatening airway obstruction. It may present as a primary infection or occur as a bacterial complication of a viral infection of the upper respiratory tract. The infection produces marked swelling and thick, purulent secretions of the tracheal mucosa below the vocal cords. The secretions can form a thick plug that may ultimately lead to an acute tracheal obstruction. Patients appear toxic, with high fever and a croup-like syndrome that can progress rapidly. The usual treatment for croup is ineffective in these patients. The characteristic "membranes" may be seen on x-rays of the airway as edema with an irregular border of the subglottic tracheal mucosa. On direct laryngoscopy, copious purulent secretions can be found in the presence of a normal epiglottis. The differential diagnosis includes acute laryngotracheobronchitis, retropharyngeal abscess, peritonsillar abscess, foreign-body aspiration, and acute diphtheric laryngitis.Emergency Department Treatment and DispositionOtolaryngologic consultation should be obtained as soon as the diagnosis is considered. Direct visualization of the trachea is more important than a possible radiologic diagnosis. Aggressive airway management, including endotracheal intubation, may be needed to protect the airway and allow for repeated suctioning to prevent acute airway obstruction. The patient should be admitted to the intensive care unit for close monitoring and sedation needs. Appropriate antibiotic coverage against suspected organisms should be instituted immediately.FIGURE 14.65.

View Full Size|Save Figure|Download Slide (.ppt)Membranous Tracheitis.Lateral soft tissue x-ray of the neck in a 13-year-old girl with the acute onset of stridor after 3 days of sore throat. Membranes (arrows) are visible in the subglottic region. (Photo contributor: Matthew R. Mittiga, MD.)Pearls1. Bacterial tracheitis often presents with acute, severe airway obstruction after a short prodrome. It should be suspected in all patients with an atypical croup-like presentation: unusual age group, toxicity, not improving with routine croup therapy, and unusual roentgenographic changes of the trachea.2. Up to 50% of soft tissue films may delineate a subglottic membrane.

AMA CitationMittiga MR, Gonzalez del Rey JA, Ruddy RM.Chapter 14. Pediatric Conditions.In:Knoop KJ, Stack LB, Storrow AB, Thurman R.eds.The Atlas of Emergency Medicine, 3e.New York, NY: McGraw-Hill; 2010

Bacterial TracheitisBacterial tracheitis (pseudomembranous croup) is a severe, life-threatening form of laryngotracheobronchitis. As the management of severe viral croup has been improved with the use ofdexamethasoneand vaccination has decreased the incidence of epiglottitis, tracheitis is a more common cause of a pediatric airway emergency requiring admission to the pediatric intensive care unit. This diagnosis must be high in the differential when a patient presents with severe upper airway obstruction and fever. The organism most often isolated isStaphylococcus aureus,but organisms such asH influenzae,group AStreptococcus pyogenes, Neisseriaspecies,Moraxella catarrhalis,and others have been reported. A viral prodrome is common. Viral coinfections are described and should be treated especially Influenza A and H1N1. The disease probably represents localized mucosal invasion of bacteria in patients with primary viral croup, resulting in inflammatory edema, purulent secretions, and pseudomembranes. Although cultures of the tracheal secretions are frequently positive, blood cultures are almost always negative.Clinical FindingsSYMPTOMS AND SIGNSThe early clinical picture is similar to that of viral croup. However, instead of gradual improvement, patients develop higher fever, toxicity, and progressive or intermittent severe upper airway obstruction that is unresponsive to standard croup therapy. The incidence of sudden respiratory arrest or progressive respiratory failure is high; in such instances, airway intervention is required. Findings of toxic shock and the acute respiratory distress syndrome may also be seen. Recently, subsets of patients with tracheal membranes have been reported with a less severe initial clinical presentation. Nevertheless, these patients are still at risk for life-threatening airway obstruction. Aggressive medical treatment and debridement still must occur in these patients.LABORATORY FINDINGS AND IMAGINGThe white cell count is usually elevated with a left shift. Cultures of tracheal secretions usually demonstrate one of the causative organisms. Lateral neck radiographs show a normal epiglottis but severe subglottic and tracheal narrowing. Irregularity of the contour of the proximal tracheal mucosa can frequently be seen radiographically and should elicit concern for tracheitis. Bronchoscopy showing a normal epiglottis and the presence of copious purulent tracheal secretions and membranes confirms the diagnosis.TreatmentPatients with suspected bacterial tracheitis will require direct visualization of the airway in a controlled environment and debridement of the airway. Most patients will be intubated because the incidence of respiratory arrest or progressive respiratory failure is high. Patients may also require further debridement, humidification, frequent suctioning, and intensive care monitoring to prevent endotracheal tube obstruction by purulent tracheal secretions. Intravenous antibiotics to coverS aureus, H influenzae,and the other organisms are indicated. Thick secretions persist for several days, usually resulting in longer periods of intubation for bacterial tracheitis than for epiglottitis or croup. Despite the severity of this illness, the reported mortality rate is very low if it is recognized and treated promptly.Hopkins, Brandon S et al: H1N1 influenza A presenting as bacterial tracheitis. OtolaryngologyHead and Neck Surgery 2010;142(4):612.[PubMed: 20304287]Tebruegge M et al: Bacterial tracheitis: A multi-centre perspective. Scand J Infect Dis 2009:110.[PubMed: 19401934]

AMA CitationFederico MJ, Stillwell P, Deterding RR, Baker CD, Balasubramaniam V, Zemanick ET, Sagel SD, Halbower A, Burg CJ, Kerby GS.Chapter 19. Respiratory Tract & Mediastinum.In:Hay WW, Jr, Levin MJ, Deterding RR, Abzug MJ, Sondheimer JM.eds.CURRENT Diagnosis & Treatment: Pediatrics, 21e.New York, NY: McGraw-Hill; 2012

BacterialTracheitisPrinciples of Disease.Bacterialtracheitis(membranous croup, bacterial croup, pseudomembranous croup) is a relatively rare but serious cause of stridor and airway obstruction in children. The epidemiology of upper airway infections has changed since widespread immunization forH. influenzaeand use of steroids for croup. This has increased the relative frequency of bacterialtracheitisas a cause of respiratory failure from upper airway infection. A recent series of 35 pediatric ICU admissions for life-threatening airway infections reported that 17 were for bacterialtracheitis, 16 for viral croup, and 2 for epiglottitis.[58]Bacterialtracheitisgenerally affects younger children, with a peak incidence at approximately 3 to 4 years of age. However, it is also reported in patients well beyond this age group, thus making it a diagnosis seen in adolescence and young adulthood as well.The pathogenesis of bacterialtracheitisis severe inflammation of the tracheal epithelium and the production of thick mucopurulent secretions. The lining of the trachea forms a loosely adherent membrane that sloughs into the lumen. Traditionally,S. aureushas been the organism primarily responsible for bacterialtracheitis. More recently, the microbiology of bacterialtracheitishas been better defined. In a review of bacterialtracheitisin 14 children, Brook reported that aerobic bacteria (43%), anaerobic bacteria (20%), and mixed anaerobic and aerobic flora (36%) were cultured. The predominant organisms recovered in tracheal secretions wereS. aureus(5),H. influenzaetype b (4),Moraxella catarrhalis(2),Peptostreptococcusspecies (4),PrevotellaandPorphyromonas(4), andFusobacteriumspecies (2).[59]Others have reportedS. pneumoniae, alpha-hemolytic and group A streptococci, andCandida albicans.Clinical Features.The clinical features of bacterialtracheitisoverlap the symptoms of both croup and epiglottitis (Table 168-2). Patients experience a viral prodrome of fever, barky cough, and stridor. These symptoms typically intensify. The child appears toxic, and signs of airway obstruction and respiratory failure may develop acutely. Differentiation of bacterialtracheitisfrom severe croup or epiglottitis on clinical grounds alone can be difficult. In one report of 16 patients with bacterialtracheitis, an initial diagnosis of croup was made in 7 and acute epiglottitis in 2.[60]Features that suggest bacterialtracheitisinclude a viral prodrome followed by acute decompensation, symptoms atypical for croup (high fever, cyanosis, and severe distress), poor response to usual treatment of croup (steroids and aerosolized epinephrine), and both inspiratory and expiratory stridor.

Table 168-2--Comparison of Croup, Epiglottitis, and BacterialTracheitisCROUPEPIGLOTTITISBACTERIALTRACHEITIS

Peak age6 months to 3 years5-7 years, but can be seen throughout childhood3-5 years, but seen throughout childhood

Pathologic featuresSubglottic inflammation, edemaInflammation and edema of the epiglottis, aryepiglottic foldsBacterial superinfection with inflammation of the tracheal mucosa, copious mucopurulent secretions obstructing the trachea

OrganismsParainfluenza virus, RSV, adenovirusGroup A beta-hemolytic streptococcus,Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzaeStaphylococcus aureusor mixed flora

Clinical featuresOnset follows URI prodrome consisting of croupy cough, hoarse voice, low-grade fever, inspiratory stridorRapid progression of high fever, toxicity, drooling, stridorSeveral-day prodrome of crouplike illness progressing to toxicity, inspiratory and expiratory stridor, marked distress

Laboratory and radiographic findingsSteeple sign on PA view of the neck, or normalThumbprint sign on lateral aspect of the neck, thickened aryepiglottic folds, loss of air in the valleculaNormal upper airway structures, shaggy tracheal air column

ManagementSteroids uncommon, aerosolized epinephrineIntubation, antibioticsIntubation common, antibiotics rare, intubation

PA,posteroanterior;RSV,respiratory syncytial virus;URI,upper respiratory infection.

Diagnostic Strategies.Evaluation of a toxic-appearing child with bacterialtracheitisshould be conducted expeditiously. Laboratory tests are nondiagnostic. The white blood cell count is normal or slightly elevated. Blood cultures are usually negative. Lateral and anteroposterior views of the neck and chest may be helpful. Findings on plain radiographs include subglottic narrowing, a ragged edge of the usually smooth tracheal air column, and a hazy density within the tracheal lumen. The epiglottis and supraglottic structures appear normal. In addition, the chest radiograph may reveal coexisting pneumonia. Bronchoscopy is both diagnostic and therapeutic and should be performed on an emergency basis. This procedure should allow visualization of the supraglottic structures and larynx, exclusion of other disease, suctioning of tracheal secretions and debris, and establishment of an artificial airway.Management.In relatively few cases, severe distress requires immediate intubation and suctioning in the ED. Airway management in the setting of the operating room is preferred. These patients require hospital admission, intensive care, supplemental oxygen, fluid resuscitation, and broad-spectrum antibiotics.Endotracheal intubation is required in the majority of patients.[58,61]The duration of intubation in patients with bacterialtracheitisis reported to be 4 or 5 days, as opposed to 48 hours for croup and 54 hours for epiglottitis.[60]Complications that have been reported in association with bacterialtracheitisinclude toxic shock syndrome, septic shock, renal failure, postintubation pulmonary edema, acute respiratory distress syndrome, and need for reintubation.[61]

Marx: Rosen's Emergency Medicine - Concepts and Clinical Practice,8th ed.Copyright 2013 Saunders, An Imprint of Elsevier