PROLOGUE: A MYSTERY CASE

CASE: HPI BV. 14 year old F Remote tonsillectomy and ESS x 2 In the ED with 9 d h/o sore throat and

odynophagia. Antecedent ‘head cold’ 4 d prior, has since resolved with conservative measures.

Developed intense L otalgia 2 d ago. Treated with amoxicillin for putative AOM → no improvement.

Last night, spiked fevers to 101. 5 F. Had emesis. Not tolerating PO.

Courtesy of BCM Dept. OTO-HNS. Grand Rounds Archives. 16 Sept 2010

CASE: PHYSICAL VITALS: T 102.5 | BP 138/66 | HR 116 | R 24 | SpO2

97% RA GEN: Sitting comfortably. Phonation is normal. No

drooling. EARS: L pre-auricular tenderness. External ears normal.

TMs quiet bilaterally. NOSE: Normal nares, septum, and turbinates. MOUTH: Mandible centered. Moderate trismus.

Tonsils surgically absent. Posterior pharynx with L > R fullness, no erythema or exudates.

NECK: No meningismus. Mildly restricted active ROM to L. Tenderness at Level II on L > R.

PULM:Respirations relaxed. No stridor. Lung fields clear throughout.

NEURO: Mental status is clear. No lateralizing deficits.

CASE: LABS and STUDIES CBC: WBC 21,000 with 85% PMNs, 15% band

forms BMP: Na 149, K 5.1, Cr 1.4, BUN: 30 Rapid Strep: Non-reactive AP Neck Film: Unremarkable CXR: Unremarkable

Common Infections of the Deep Neck Spaces: An Overview

Victor Tseng, MS-3OTO-HNS Subrotation

DEEP NECK SPACES: Eleven anatomic or potential compartments created by interfascial planes within the neck

DEEP NECK INFECTION: A supperative (usually bacterial) infection within the deep neck spaces of the deep cervical fascia

DEFINITIONS

AXIAL ANATOMY

SAGITTAL ANATOMY

SAGITTAL ANATOMY

RADIOLOGIC ANATOMY

HEAD AND NECK AXIAL MRI

FLYTHROUGH (LINK)

A MENU OF SPACES: PEARLSSUPRAHYOID

PARAPHARYNGEAL (PP): A major nexus of contiguous spread. Transmits the carotid sheath. Isolated involvement is uncommon.

SUBMANDIBULAR (SM): Infection may lead to upper airway obstruction MASTICATOR: Most closely associated with trismus. Almost exclusively

secondary to odontogenic causes. PAROTID: Most likely seen in dehydrated and decrepit patients with poor

dentition TEMPORAL: Between temporalis fascia and temporal bone periostium PERITONSILLAR (PTS): Most common site overall, but not aknowledged as a

true DNI, since it is not defined by fascial apposition

INFRAHYOID RETROPHARYNGEAL (RPA): Extends from skull base to level of carina (T2).

Does not communicate with the pleural space. DANGER: Infection easily escapes into the mediastinum and pleural space PREVERTEBRAL (PV): Extends to coccyx and may develop into psoas absess. CAROTID: Associated with IVDA and septic thromboembolism PRETRACHEAL (PT): Associated with anterior perforation of the esophageal

wall

HOOFBEATS: COMMONS

PERITONSILLAR (49%) RETROPHARYNGEAL (22%, 43% non-

PTS) Most common DNI across all age groups But it is predominantly a pediatric

infection SUBMANDIBULAR (14%, 27% non-PTS) PAROTID (11%)

RETROPHARYNGEAL ABSCESS (RPA) EPIDEMIOLOGY

> 75% of cases occur < 6 years old. 50% of cases occur by 12 mos. Overall (treated) mortality approximately 1%

ETIOLOGY Children (< 18 years): 60% related to supperative LAD due to URI,

AOM, acute sinusitis Adults: Mostly due to trauma, foreign body, instrumentation, or

contiguous extension from primary DNI MICROBIOLOGY

>90% are polymicrobial. Average n = 5 microbes isolated from culture.

>50% of isolates grow anerobes S. pyogenes > S. aureus > oropharyngeal anaerobes > H. influenzae

PATHOPHYSIOLOGY supperative lymphadenitis → organized phlegmon → mature abscess Morbidty and mortality is due to development of complications

RETROPHARYNGEAL ABSCESS (RPA) CLINICAL PRESENTATION

Adults: Sore Throat > Fever > Dysphagia > Odynophagia > Nuchal Pain > Dyspnea > Hoarseness

Children: Sore Throa (84%) > Fever (64%) > Odynophagia (55%) > Cough

Infants: Neck Fullness (97%) > Fever (85%) > Poor PO (55%) DIFFERENTIAL DIAGNOSIS

Epiglottitis, PTA, Croup, Diphtheria Angioedema Respiratory lymphagiomas or hemangiomas Traumatic esophagus or airway, foreign body impaction

COMPLICATIONS Acute Mediastinitis: very high (>50%) mortality Empyema Pericardial effusion with tamponade physiology Mass effect: supraglottic airway obstruction (anterior) or epidural

abscess (posterior)

RETROPHARYNGEAL ABSCESS (RPA) PHYSICAL FINDINGS

Adults: pharyngeal edema > cervical LAD > nuchal rigidity > drooling > stridor

Children: fever and nuchal rigidity (64%) > retropharyngeal bulge and neck mass (55%) > agitation or lethargy > drooling (22%) > respiratory distress or stridor

Other: dystonic reactions (torticollis), dysphonia (‘hot potato’ voice), trismus

In a drooling or stridorous patient, be minimally invasive when examining the pharynx

LABORATORY CBC: 20% of cases may not show leukocytosis or relative left shift Standard GAS rapid throat swab and culture Blood cultures: rarely return positive growth Wound culture: 91% sensitivity for polymicrobial infection CRP and ESR to follow baseline. CRP is actually prognostic of

hospitalization legnth. Pre-operative labs in anticipation of surgical intervention (coagulation

panel, metabolic panel, type and cross)

RETROPHARYNGEAL ABSCESS (RPA) IMAGING

Lateral Neck Film: look for widened AP diameter of retropharyngeal tissue. Maximal reported sensitivity of 88%.

CT Neck with Contrast Most important imaging test to consider Hypodense lesion of retropharyngeal space with rim enhancement Absolute Indications: equivocal LNF, negative LNF with high clinical

suspicion Sensitivity 77 – 100% , Specificity 95%

High-Resolution U/S Maybe used to track abscess during hospitalization. Some anatomic

insight into surrounding vascular structures. Proof of concept. No data to support routine use.

MRI: Not recommended for initial evaluation due to untimeliness

Flexible Endoscopy: not recommended

RETROPHARYNGEAL ABSCESS (RPA)

RETROPHARYNGEAL ABSCESS (RPA) MEDICAL MANAGEMENT PARENTERAL ANTIBIOTIC THERAPY is guided by suspected source of infection!

Must have MRSA coverage if strain is endemic, poor clinical response to clindamycin, or in patients with very severe disease

SUSPECTED SOURCE

FIRST-LINE THERAPY ALTERNATIVE

Odontogenic Ampicillin-Sulbactam 3 g IV q6h

Penicillin G 2-4 MU IV q4-6h + Metronidazole 500 mg IV q6-8h

Clindamycin 600 mg IV q6-8h

Imipenem 500 mg IV q6h

Meropenem 1 g IV q8h

Rhinogenic and Otogenic

Ampicillin-sulbactam 3 g IV q6h

Ceftriaxone 1 g IV q24h +Metronidazole 500 mg IV q6-8h

Ciprofloxacin 400 mg q12h + Clindamycin 600 mg IV q6-8h

As above

Immuncompromised Cefipime 2 g IV q12h + Metronidazoole 500 g IV q6h

Piperacillin-Tazobactam 4.5 g IV q6h

As above

RETROPHARYNGEAL ABSCESS (RPA) SURGICAL INDICATIONSImportant: > 50% of patients with uncomplicated RPA

achieve spontaneous resolution with medical therapy alone

Respiratory distress Urgent complication of RPA (e.g. mediastinitis,

empeyema, septic thrombophlebitis) Diameter of abscess > 2 cm on CT Neck No response to ABx therapy at 48 hrs

SURGICAL APPROACH U/S guided FNA: preferred in hemodynamically unstable

patients, or those with small and accessible loculations I/D: Usually requires trans-cervical entry. Small abscesses may

be drained via trans-oral aspiration.

QUESTIONS