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Retropharyngeal Abscess, Emergency Medicine

Basics

Description

- Prognosis is good when promptly diagnosed and aggressively managed with IV antibiotics and/or surgical drainage - Complications due to mass effect, rupture, or spread are the major source of morbidity and include: - Airway compromise (most common) - Aspiration pneumonia due to rupture - Sepsis - Spontaneous perforation - Necrotizing fasciitis - Mediastinitis - Thrombosis of the internal jugular vein - Jugular vein suppurative thrombophlebitis (Lemierre syndrome) - Erosion into carotid artery (primarily adults) - Atlantoaxial dislocation from erosion of ligaments - Cranial nerve palsies (typically IX " XII) - Epidural abscess - Recurrent abscess formation (1 " 5%)

- Bacteriology: Predominately polymicrobial with anaerobes and aerobes - Most common organisms are: - Streptococcus pyogenes and Streptococcus viridans - Staphylococcus aureus (including MRSA) - Respiratory anaerobes (including Prevotella, Fusobacterium, and Veillonella)

- Less common organisms are: - Haemophilus species - Acid-fast bacilli - Klebsiella pneumoniae - Escherichia coli - Mycobacterium tuberculosis - Aspergillus and Candida species

- Additional presenting symptoms: - Stridor, dyspnea - Muffled voice - Trismus

- Portable films appropriate if concern for airway compromise - Lateral neck radiographs: - Film taken in inspiration with neck slightly extended - May not get good exposure of soft tissue if cannot adequately extend neck due to pain or difficulty cooperating in young age - Increased suspicion if: - Retropharyngeal space anterior to C2 >7 mm or 2 the diameter of the vertebral body (sensitivity 90%) - Space anterior to C6 >14 mm in preschool children or 22 mm in adults - Loss of normal cervical lordosis

- CT of neck with IV contrast: - Now preferred imagining modality - Obtain when x-rays nondiagnostic or to determine exact size and location of abscess noted on x-ray - Abscess appears as hypodense lesion with peripheral ring enhancement in retropharyngeal space - Sensitivity: 64 " 100% - Specificity: 45 " 88% - Can aid in operative planning, revealing extent of invasion into retro/parapharyngeal spaces - Unclear if it reliably can distinguish abscess from cellulitis and lymphadenitis - Due to radiation exposure and need for sedation, CT should only be obtained in young children if x-rays are nondiagnostic

- Early endotracheal intubation or tracheostomy for patients with respiratory distress or impending obstruction: - Caution must be used with induction, as sedation medications may lead to relaxation of airway muscles causing complete obstruction - Rescue airway equipment such as a laryngeal mask airway available, as pharyngeal swelling may make intubation difficult - Cricothyrotomy may be required if upper airway is obstructed

- ICU admission for patients with: - Airway compromise - Sepsis - Altered mental status - Hemodynamic instability - Infants and toxic-appearing children - Major comorbidities

  • Deep tissue infection of the retropharyngeal space:Potential space bound anteriorly by buccopharyngeal fascia, posteriorly by alar fascia, superiorly by skull base, inferiorly by fusion of fascial layers at T2Space fused by raphe at midline with chains of lymph nodes extending down each sideAlar fascia is poor barrier and allows retropharyngeal infections to spread into "danger " space and posterior mediastinum
  • Primarily a disease of children, but increasing frequency in adults:Peak incidence at 3 " 5 yr when retropharyngeal nodes most prominent
  • Prognosis is good when promptly diagnosed and aggressively managed with IV antibiotics and/or surgical drainage
  • Complications due to mass effect, rupture, or spread are the major source of morbidity and include:Airway compromise (most common)Aspiration pneumonia due to ruptureSepsisSpontaneous perforationNecrotizing fasciitisMediastinitisThrombosis of the internal jugular veinJugular vein suppurative thrombophlebitis (Lemierre syndrome)Erosion into carotid artery (primarily adults)Atlantoaxial dislocation from erosion of ligamentsCranial nerve palsies (typically IX " XII)Epidural abscessRecurrent abscess formation (1 " 5%)

Etiology

  • Causes:Most often arises from infection of nasopharynx, paranasal sinuses, or middle earInfection then spreads to lymph nodes between posterior pharyngeal wall and alar fasciaTrauma, foreign bodies, and iatrogenic introduction of infection from instrumentation also common cause, especially in adultsDiabetes and other immunosuppressed states may predispose to this infection
  • Bacteriology: Predominately polymicrobial with anaerobes and aerobes
  • Most common organisms are:Streptococcus pyogenes and Streptococcus viridansStaphylococcus aureus (including MRSA)Respiratory anaerobes (including Prevotella, Fusobacterium, and Veillonella)
  • Less common organisms are:Haemophilus speciesAcid-fast bacilliKlebsiella pneumoniaeEscherichia coliMycobacterium tuberculosisAspergillus and Candida species

Diagnosis

Signs and Symptoms

May differ between adults and children

History

  • Most common:Sore throatNeck pain/stiffnessOdynophagiaDysphagiaFever
  • Additional presenting symptoms:Stridor, dyspneaMuffled voiceTrismus

Young children may present with only:

  • Poor oral intake
  • Lethargy or irritability
  • Cough

Physical Exam

  • Adults:Posterior pharyngeal edemaNuchal rigidityCervical adenopathyFever (67%)DroolingStridorDysphonia (cri du canard)Tracheal "rock " sign: Tenderness on moving the larynx and trachea side to side
  • Children and infants:Cervical adenopathyFeverNeck stiffness with extension most frequently limitedRetropharyngeal bulgeTrismusTorticollisDroolingAgitationRespiratory distress

Essential Workup

Rapid assessment of airway and respiratory status:

  • Normal exam does not rule out diagnosis
  • No lab tests make the diagnosis
  • When suspicious, obtain lateral neck x-ray or CT of neck with IV contrast

Diagnosis Tests & Interpretation

Lab

  • CBC (WBC >12,000 in 91% of children):
  • Blood cultures (both aerobic and anaerobic)
  • Throat cultures

Imaging

  • Portable films appropriate if concern for airway compromise
  • Lateral neck radiographs:Film taken in inspiration with neck slightly extendedMay not get good exposure of soft tissue if cannot adequately extend neck due to pain or difficulty cooperating in young ageIncreased suspicion if:Retropharyngeal space anterior to C2 >7 mm or 2 the diameter of the vertebral body (sensitivity 90%)Space anterior to C6 >14 mm in preschool children or 22 mm in adultsLoss of normal cervical lordosis
  • Chest radiograph:Indicated if abscess identified to assess for inferior spread of infection and/or aspiration of ruptured abscess contentsMediastinal widening is suggestive of mediastinitis and possible rupture
  • US of neck:Low sensitivityNot recommended
  • CT of neck with IV contrast:Now preferred imagining modalityObtain when x-rays nondiagnostic or to determine exact size and location of abscess noted on x-rayAbscess appears as hypodense lesion with peripheral ring enhancement in retropharyngeal spaceSensitivity: 64 " 100%Specificity: 45 " 88%Can aid in operative planning, revealing extent of invasion into retro/parapharyngeal spacesUnclear if it reliably can distinguish abscess from cellulitis and lymphadenitisDue to radiation exposure and need for sedation, CT should only be obtained in young children if x-rays are nondiagnostic
  • MRI:More sensitive than CTAlso useful for imaging vascular lesions such as jugular thrombophlebitis

Diagnostic Procedures/Surgery

  • Surgical drainage/needle aspiration should be performed in OR:Presence of pus is gold standard for making diagnosisAbscess should be completely evacuatedPus should be sent for Gram stain and culture
  • No role for nasopharyngolaryngoscopy

Differential Diagnosis

  • Tonsillopharyngitis
  • Epiglottitis
  • Peritonsillar abscess
  • Croup
  • Foreign body
  • Tracheitis
  • Meningitis
  • Retropharyngeal hemorrhage
  • Dystonic reactions
  • Cervical osteomyelitis
  • Dental infections
  • Mononucleosis
  • Epidural abscess
  • Other deep space infection of the neck

Treatment

Pre-Hospital

  • Keep child in position of comfort:Forcing child to sit up or flex neck may occlude airway
  • Pulse oximetry, cardiac monitor
  • Supplemental oxygen
  • Adequate hydration
  • Suction, endotracheal tube, tracheostomy equipment ready for potential emergent intubation
  • Airway control will be required for:Airway compromisePrior to long transport

Initial Stabilization/Therapy

  • Assess and control airway
  • Provide supplemental oxygen
  • IV access:Avoid if signs of airway compromise

Ed Treatment/Procedures

  • Early endotracheal intubation or tracheostomy for patients with respiratory distress or impending obstruction:Caution must be used with induction, as sedation medications may lead to relaxation of airway muscles causing complete obstructionRescue airway equipment such as a laryngeal mask airway available, as pharyngeal swelling may make intubation difficultCricothyrotomy may be required if upper airway is obstructed
  • Surgical consultation (ear/nose/throat if available)
  • Early administration of IV antibiotics

Medication

Empiric IV antibiotic therapy to cover group A streptococci, S. aureus (including MRSA), and respiratory anaerobes:

  • Antibiotic tailored to local preferences and susceptibilities
  • Coverage is narrowed when culture results and sensitivities return
  • Use of corticosteroids is controversial and recommended only after consultation with ear/nose/throat
  • Immunocompromised, diabetics, IV drug users, institutionalized patients, and young children (<1 yr) at high risk for MRSA

First Line

Several antibiotic regimens are available:

  • Clindamycin: 600 " 900 mg (peds: 25 " 40 mg/kg/24 h) IV q8h (max. 4.8 g/d)
  • Clindamycin + Metronidazole (loading dose 15 mg/kg IV not to exceed 4 g/d followed by 7.5 mg/kg PO/IV)
  • Penicillin G + Metronidazole
  • Cefoxitin 1 g IV q6 " 8h/3 " 4 g/d max.
  • Ticarcillin/Clavulanate 3.1 g IV q4 " 6h
  • Piperacillin/Tazobactam 3.375 g IV q6h

Second Line

If patients do not respond or there is concern for MRSA:

  • Vancomycin: 15 " 20 mg/kg (peds: 40 " 60 mg/kg/24 h IV q6 " 8h) IV q12h
  • Linezolid: 600 mg (peds: 0 " 11 yr: 30 mg/kg/24 h q8h; >12 yr: Adult dose) IV/PO q12h

Follow-Up

Disposition

Admission Criteria

  • All patients with retropharyngeal abscess should be admitted to the hospital for IV antibiotics and possible surgical drainage
  • Criteria for surgical drainage:Airway compromise or other life-threatening complicationsLarge (>2 cm hypodense area on CT)Failure to respond to parenteral antibiotic therapy
  • ICU admission for patients with:Airway compromiseSepsisAltered mental statusHemodynamic instabilityInfants and toxic-appearing childrenMajor comorbidities

Discharge Criteria

Patients with retropharyngeal abscesses should not be discharged

Issues for Referral

Transfer should be considered if facility does not have the ability to drain infection:

  • Airway should be stabilized prior to transfer

Pearls and Pitfalls

  • Diagnosis should be considered in all children who present with fever, stiff neck, or dysphagia:High clinical suspicion is required in children, as they present with nonspecific signs and symptoms
  • Adult cases most often present in the setting of underlying illness, recent intraoral procedures, neck trauma, or head and neck infections
  • When imaging is nondiagnostic and clinical suspicion remains high, surgery should be consulted
  • Early surgical consultation and administration of IV antibiotics is essential to prevent complications such as airway compromise and extension into mediastinal structures

Additional Reading

  • Chow AW. Deep neck space infections. UpToDate February 17, 2012. Available at http://www.uptodate.com/contents/deep-neck-space-infections.
  • Marx JA, Hockberger RS, Walls RM, et al. Rosens Emergency Medicine: Concepts and Clinical Practice. 7th ed. St. Louis, MO: Mosby; 2010.
  • Page NC, Bauer EM, Lieu JE. Clinical features and treatment of retropharyngeal abscess in children. Otolaryngol Head Neck Surg. 2008;138:300 " 306.
  • Reynolds SC, Chow AW. Severe soft tissue infections of the head and neck: A primer for critical care physicians. Lung. 2009;187:271 " 279.
  • Wald ER. Retropharyngeal infections in children. UpToDate August 17, 2012. Available at http://www.uptodate.com/contents/retro pharyngeal-infections-in-children.

See Also (Topic, Algorithm, Electronic Media Element)

  • Epiglottitis
  • Peritonsillar Abscess

Codes

ICD9

478.24 Retropharyngeal abscess

ICD10

J39.0 Retropharyngeal and parapharyngeal abscess

SNOMED

  • 18099001 retropharyngeal abscess (disorder)