Management of Lung Abscess

Initial Approach

• The initial approach for a patient with lung abscess should include intravenous antibiotics with anaerobic coverage, such as ceftriaxone 1-2g IV every 12-24 hours PLUS clindamycin 600-900mg IV every 8 hours or metronidazole 500mg IV every 8 hours, as recommended by the American Journal of Respiratory and Critical Care Medicine and the Infectious Diseases Society of America 1, 2
• Clinical assessment every 48-72 hours is necessary to monitor fever resolution, improvement in cough and sputum production, decreasing leukocytosis, and improved appetite and activity level, with a strength of evidence based on clinical guidelines 2

Antibiotic Therapy

• The European Respiratory Journal recommends initiating a multidrug regimen with at least three active drugs based on susceptibility testing for patients with lung abscess, and considering surgical resection for localized disease 3
• Initial empiric therapy with intravenous third-generation cephalosporin, such as ceftriaxone 1-2g IV every 12-24 hours or cefotaxime 2g IV every 6-8 hours, for a minimum of 2-4 weeks based on clinical response, is recommended by the American College of Physicians 4
• Combination therapy with intravenous amikacin, intravenous imipenem or cefoxitin, and tigecycline, with the addition of oral macrolide if sensitive, is recommended for lung abscess treatment 5, 6, 7
• The following antibiotic regimen is recommended:

• For lung abscesses caused by specific pathogens like M. abscessus, targeted therapy based on culture and sensitivity is essential, with a multidrug regimen including at least three active drugs for a minimum of 12 months after culture conversion, as recommended by the Infectious Diseases Society of America 8
• The European Respiratory Society and Clinical Infectious Diseases society recommend a treatment regimen that includes at least three antibiotics active against M. abscessus, guided by in vitro susceptibility, for a minimum of 4 weeks in the initial phase 3, 8

Surgical Consultation

• Surgical consultation should be considered if there is failure to respond to medical therapy after 7-10 days, significant hemoptysis, large abscess (>6cm), or suspected underlying malignancy, as surgical intervention is required in approximately 10% of lung abscess cases 3
• Surgery is indicated in approximately 10% of lung abscess cases, specifically for failure of medical and interventional therapy, prolonged sepsis, significant hemoptysis, bronchopleural fistula, empyema, suspected underlying malignancy, and for M. abscessus, surgical resection combined with chemotherapy is the only predictably curative therapy for focal disease 5, 6, 9

Monitoring and Follow-up

• Patients should be monitored for clinical improvement, with follow-up chest imaging at 4-6 weeks to document resolution, and calcium levels should be monitored weekly after discharge until normalized, then monthly for 3 months 3
• Chest radiograph at 7-10 days is recommended to assess for improvement, and consider repeat CT scan if clinical deterioration or inadequate response occurs 2
• The total antibiotic duration is typically 4-8 weeks depending on clinical and radiographic response, as recommended by clinical evidence 2
• Switch to oral antibiotics when patient shows clinical improvement, including being afebrile for 48-72 hours, improved symptoms, and decreasing white blood cell count, as a general principle of antibiotic stewardship 2
• Patients are eligible for discharge when they demonstrate overall clinical improvement, including activity level and appetite, decreased fever for at least 12-24 hours, stable oxygen saturation >90% on room air, and ability to tolerate oral antibiotics, based on general principles of patient care 2

Risk Factors and Prevention

• Poor oral hygiene and periodontal disease are risk factors for lung abscesses, particularly in patients over 65 years old, with a history of residence in care institutions, and those with chronic pulmonary diseases or comorbidities such as cardiovascular, neurological, or renal diseases, as suggested by the European Respiratory Society 10
• Recent hospitalization, especially within the last year, increases the risk of developing lung abscesses due to potential exposure to multidrug-resistant pathogens, as noted by the European Respiratory Society and the American Journal of Respiratory and Critical Care Medicine 10, 11
• Implementing strategies to reduce the risk of lung abscesses, including strict infection control, hand hygiene with alcohol-based disinfectants, and surveillance for multidrug-resistant pathogens, is recommended by the American Journal of Respiratory and Critical Care Medicine 11

Diagnosis and Prognosis

• Diagnosis of pulmonary abscess is based on clinical manifestations (cough with purulent expectoration, fever, chest pain, dyspnea, and hemoptysis) and imaging studies, including computed tomography (CT) scans, which show a cavity with a fluid level, thick walls, and necrotic content, as noted by the European Respiratory Society and Thorax 3, 9, 12
• Prognosis of pulmonary abscess depends on factors such as underlying diseases, immune status, response to initial antibiotic treatment, and size and location of the abscess, as stated by the Thorax journal and the American College of Radiology 13, 9