What anesthesia methods are recommended for treating retropharyngeal abscess?

Anesthesia Management for Retropharyngeal Abscess

Primary Recommendation

For retropharyngeal abscess requiring surgical drainage, awake fiberoptic intubation with topical anesthesia is the safest approach when feasible, as it maintains spontaneous ventilation and airway patency in patients with critical upper airway obstruction. 1, 2, 3

Critical Airway Assessment

Pre-Anesthetic Evaluation

• Assess airway patency immediately using CT or MRI imaging to determine abscess size, location, and degree of airway narrowing 4, 2, 5
• Retropharyngeal abscesses can cause airway diameter reduction to as little as 8 mm with lateral epiglottic displacement 3
• Severe cases may present with stridor, dyspnea, and restricted cervical mobility requiring immediate airway intervention 4, 2, 5
• Interdental distance measurement is essential, as trismus (opening <1.5 cm) indicates difficult direct laryngoscopy 3

Risk Stratification

• Pediatric patients and those with massive abscesses are at highest risk for complete airway obstruction during induction 5
• One case report documented failed intubation by an experienced airway surgeon requiring emergent tracheotomy in a 14-month-old 5
• Upper airway obstruction is considered standard indication for neuromuscular blockade in adults when airway control is anticipated to be successful 1

Recommended Anesthetic Techniques

First-Line: Awake Fiberoptic Intubation (High-Risk Patients)

This is the gold standard for patients with significant airway compromise, immunocompromised status, or inability to tolerate general anesthesia. 2, 3

Technique:

• Patient positioned sitting upright to optimize airway patency and reduce aspiration risk 1, 3
• Gargle 10 mL of 0.5% lidocaine for oropharyngeal topicalization 3
• Advance pediatric fiberoptic bronchoscope (3.1 mm) through orally-inserted nasopharyngeal airway to identify glottis 3
• Spray 0.5% lidocaine onto airway mucosa under direct visualization 3
• Replace nasopharyngeal airway with reinforced 6.5 mm internal diameter endotracheal tube over the bronchoscope 3
• Advance tube into trachea before inducing general anesthesia 3

Advantages:

• Maintains spontaneous ventilation throughout intubation 1, 2
• Avoids risks of general anesthesia in critically ill, immunocompromised patients 2
• Minimizes postoperative complications 2
• Successfully used in a 76-year-old with massive abscess, diabetes, and ischemic heart disease 2

Second-Line: Rapid Sequence Intubation with Neuromuscular Blockade

For patients with adequate airway patency where mask ventilation is anticipated to be possible, rapid sequence intubation with short-acting agents is appropriate. 1

Pre-Induction Preparation:

• Pre-oxygenate with 100% FiO2 via facemask with reservoir bag 1
• Position patient head-elevated or reverse Trendelenburg to reduce aspiration risk 1
• Have emergency tracheotomy equipment immediately available at bedside 1, 5
• Prepare videolaryngoscope as first-line intubation device 1
• Apply cricoid pressure during induction to reduce aspiration risk 1

Induction Agents:

• Propofol (1-2.5 mg/kg) or sevoflurane are the hypnotics of choice due to rapid reversibility 1, 6
• For elderly or ASA III-IV patients: reduce propofol to 1-1.5 mg/kg (approximately 20 mg every 10 seconds) 6
• Remifentanil 0.5-1 mcg/kg/min can be added to improve intubating conditions, though it increases apnea risk 1, 7

Neuromuscular Blockade:

• Succinylcholine 1 mg/kg (real weight) is recommended for its short duration allowing return of spontaneous ventilation if intubation fails 1
• Muscle relaxants improve both mask ventilation and intubation conditions in patients with upper airway obstruction 1
• Quantitative neuromuscular monitoring is mandatory 1

Intubation Technique:

• Videolaryngoscopy should be used as first-line device rather than direct laryngoscopy, as it significantly reduces Cormack-Lehane grade III/IV views 1
• Gum elastic bougie should be immediately available for optimization 1
• Limit to 1-2 intubation attempts by the most experienced practitioner before moving to rescue techniques 1
• If videolaryngoscopy fails, consider fiberoptic technique or surgical airway 1

Third-Line: Local Anesthesia with Intraoral Drainage

For critically ill patients who are not candidates for general anesthesia, drainage via posterior oropharyngeal wall incision under local anesthesia is a viable alternative. 2

• Successfully performed in a 76-year-old with multiple comorbidities and massive abscess 2
• Provides immediate symptom relief without risks of general anesthesia 2
• Requires cooperative patient and accessible abscess location 2

Critical Pitfalls to Avoid

Do NOT:

• Never perform rapid bolus induction in elderly or hemodynamically unstable patients - this causes severe cardiorespiratory depression 6
• Never assume mask ventilation will be possible - have backup oxygenation devices (supraglottic airways) immediately available 1
• Never proceed without emergency tracheotomy equipment at bedside - complete airway obstruction can occur suddenly 5
• Avoid testing mask ventilation before neuromuscular blockade administration - no evidence supports this practice 1

Essential Safety Measures:

• Maintain deep anesthesia with rapidly reversible agents to optimize mask ventilation if intubation fails 1
• Ensure 360° patient access on ambulance trolley or OR table at comfortable working height 1
• Perform verbal challenge-response checklist before induction confirming equipment, drug doses, and failed intubation plan 1
• Have minimum of 4 personnel: anesthesia provider, assistant, cricoid pressure provider, and backup surgeon 1

Surgical Approach Considerations

• Transoral drainage (n=5), transcervical (n=3), or combined approaches are all viable depending on abscess location 4
• MRI-guided transnasal drainage can be used for abscesses close to skull base 4
• Streptococcal species are the most common organisms (identified in 6/11 cases) 4
• All patients in one series recovered with surgical drainage, though one required tracheotomy during disease course 4

Post-Intubation Management

• Confirm tube placement with waveform capnography immediately - failure to use capnography contributes to airway-related deaths 8
• Consider extubation over Cook Airway Exchange Catheter in high-risk patients 3
• Extubation should only occur when TOF >90%, spontaneous breathing adequate, and patient awake 1
• Deep extubation may be considered to prevent coughing and surgical site disruption, but requires at least 1 MAC volatile agent and close monitoring for obstruction 1