Is Unasyn (ampicillin and sulbactam) effective for treating acute mastoiditis in pediatric patients?

Unasyn (Ampicillin-Sulbactam) for Acute Mastoiditis in Pediatrics

Unasyn is NOT the recommended first-line antibiotic for acute mastoiditis in pediatric patients; high-dose amoxicillin-clavulanate (80-90 mg/kg/day) or third-generation cephalosporins are preferred as initial intravenous therapy. 1

Recommended Antibiotic Regimen

For acute mastoiditis, initiate intravenous broad-spectrum antibiotics immediately upon diagnosis, with amoxicillin-clavulanate at 80-90 mg/kg/day (maximum 4000 mg/day) as the preferred first-line agent. 1

Specific Dosing for IV Amoxicillin-Clavulanate

• Administer 1333 mg IV every 8 hours (total 4000 mg/day) or 2000 mg IV every 12 hours (total 4000 mg/day) 1
• The higher end of dosing (80-90 mg/kg/day of amoxicillin component) is preferred for serious infections like mastoiditis 1

Alternative Antibiotic Options for Complicated Cases

If initial therapy fails or complications develop, broader coverage should include: 1

• Vancomycin PLUS one of the following:
  • Piperacillin-tazobactam
  • A carbapenem
  • Ceftriaxone plus metronidazole
  • A fluoroquinolone plus metronidazole

Pathogen-Specific Considerations

• Streptococcus pneumoniae remains the most common causative organism (32.5% of cases) 2, 3
• Staphylococcus aureus accounts for 21.5% of cases 2
• For confirmed Streptococcus pyogenes, consider adding clindamycin to penicillin therapy 1
• Cephalosporins are the antibiotic of choice given the prevalence of S. pneumoniae 3

Treatment Algorithm

Initial Management (0-48 Hours)

Start IV antibiotics immediately with or without myringotomy, then reassess at 48 hours. 1

• Pain management is critical and should be addressed concurrently 1
• Myringotomy with or without tympanostomy tube insertion should be considered as part of initial management 1

Decision Point at 48 Hours

If no improvement after 48 hours of IV antibiotics OR clinical deterioration at any point: 1

• Obtain CT temporal bone with IV contrast to assess for bony erosion and complications 1
• Proceed to mastoidectomy if infection is not controlled 4

Surgical Intervention Indications

Mastoidectomy should be performed if: 1, 4, 5

• Patient fails to improve after 48 hours of IV antibiotic therapy
• Clinical deterioration occurs at any time
• Coalescent mastoiditis is present
• Subperiosteal abscess develops
• Intracranial complications are identified

Treatment Success Rates

• Antibiotics alone: 10% success rate 1
• Antibiotics plus myringotomy: 68% success rate 1
• Antibiotics plus mastoidectomy: 22% of cases require this approach 1

Imaging Strategy

Obtain CT temporal bone with IV contrast if the patient fails to improve or deteriorates, as this provides high spatial resolution for assessing bony erosion and intratemporal complications. 1

Consider MRI without and with IV contrast if intracranial complications are suspected (brain abscess, subdural empyema, meningitis, or dural venous sinus thrombosis), as MRI has higher sensitivity and specificity than CT for these conditions. 1

Monitoring for Complications

Monitor vigilantly for: 1, 3

• Sigmoid sinus thrombosis
• Seizures
• Meningismus and neck rigidity
• Neurological deficits
• Facial nerve palsy
• Labyrinthitis

Brain abscess is the most common intracranial complication of otomastoiditis. 1

Transition to Oral Therapy

Once clinical improvement is noted, transition to oral antibiotics may be considered. 1

• Antibiotic choices should be guided by culture results when available 1
• Consider clindamycin with or without coverage for Haemophilus influenzae and Moraxella catarrhalis for patients who fail initial therapy 1

Follow-Up Care

Regular follow-up is essential to ensure complete resolution and monitor for complications or recurrence. 1

• Persistent middle ear effusion is common after resolution of acute symptoms and should be monitored 1
• Hearing assessment should be performed if effusion persists for ≥3 months 1

Critical Pitfalls to Avoid

Prior antibiotic treatment does NOT prevent the development of mastoiditis - 33-81% of patients diagnosed with acute mastoiditis had received antibiotics before admission. 1

No reliable clinical signs distinguish patients with coexistent intracranial complications, making imaging crucial in non-resolving cases. 1

Early mastoidectomy prevents serious complications, and broad mastoidectomy with posterior attic and facial recess exposure may prevent recurrence of acute mastoiditis. 4