1. PROLOGUE: A MYSTERY CASE

2. Courtesy of BCM Dept. OTO-HNS. Grand Rounds Archives. 16 Sept 2010
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 F. Had emesis. Not tolerating PO.
Courtesy of BCM Dept. OTO-HNS. Grand Rounds Archives. 16 Sept 2010

3. CASE: PHYSICAL
VITALS: T | 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.

4. 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

5. Common Infections of the Deep Neck Spaces: An Overview
Victor Tseng, MS-3
OTO-HNS Subrotation

6. DEFINITIONS
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

7. AXIAL ANATOMY

8. SAGITTAL ANATOMY

9. SAGITTAL ANATOMY

10. HEAD AND NECK AXIAL MRI FLYTHROUGH (LINK)
RADIOLOGIC ANATOMY
HEAD AND NECK AXIAL MRI FLYTHROUGH (LINK)

11. A MENU OF SPACES: PEARLS
SUPRAHYOID
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

12. 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%)

13. 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

14. 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)

15. 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)

16. 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

17. RETROPHARYNGEAL ABSCESS (RPA)

18. 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

19. RETROPHARYNGEAL ABSCESS (RPA)
SURGICAL INDICATIONS
Important: > 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.

20. QUESTIONS