pulmonary disorders
Lung Abscess
Treatment of Lung Abscess
IV antibiotics or, for less seriously affected patients, oral antibiotics Percutaneous, endobronchial, or surgical drainage of any abscess that does not respond to antibiotics or of any empyema The primary choice is a combination beta-lactam/beta-lactamase inhibitor, for example,ampicillin/sulbactam1.5 g (1 gampicillinplus 0.5 g sulbactam) to 3 g (2 gampicillinplus 1 g sulbactam) IV or IM every 6 hours; the dose should not exceed 12 g per day . Alternatives include a carbapenem (eg,imipenem/cilastatin500 mg IV every 6 hours) or combination therapy withmetronidazole500 mg every 8 hours plus penicillin 2 million units IV every 6 hours. In patients who are allergic to penicillin,clindamycin600 mg IV every 8 hours,moxifloxacin400 mg once daily, or combination therapy withlevofloxacin750 mg once daily withmetronidazole500 mg every 8 hours are alternative choices. Less seriously ill patients may be given oral antibiotics such asamoxicillin/clavulanic acid1 g (875/125 mg) orally every 12 hours or, in patients allergic to penicillin,clindamycin300 mg orally every 6 hours. IV regimens can be converted to oral ones when the patient defervesces. For very serious infections involving MSRA, the best treatment islinezolidorvancomycin. If gram-negative bacilli are cultured in significant concentrations from sputum or blood and are identified on gram stain, the antibiotic regimen should be modified to cover the specific pathogen in addition to anaerobes. Clindamycin600 mg IV every 6 to 8 hours was the drug of choice because it has excellent activity against streptococci and anaerobic organisms; however, it has become a second-line drug because of concern for the substantial rate ofClostridioides(formerly,Clostridium)difficileinfection ifclindamycintherapy is prolonged. It is still a useful choice in penicillin-allergic patients. Optimal duration of treatment is unknown, but common practice is to treat until the chest x-ray shows complete resolution or a small, stable, residual scar, which generally takes 3 to 6 weeks or longer. In general, the larger the abscess, the longer it will take for x-rays to show resolution. Most authorities do not recommend chest physical therapy and postural drainage because of the potential for spillage of infection into other bronchi with extension of the infection or acute obstruction. An accompanying empyema must be drained. Surgical removal or drainage of lung abscesses is necessary in the roughly 10% of patients in whom lesions do not respond to antibiotics, and in those who develop pulmonary gangrene. Resistance to antibiotic treatment is most common with large cavities and with post-obstructive abscesses. If patients fail to defervesce or to improve clinically after 7 to 10 days, they should be evaluated for resistant or unusual pathogens, airway obstruction, and noninfectious causes of cavitation. When surgery is necessary, lobectomy is the most common procedure; segmental resection may suffice for small lesions (<6 cm diameter cavity). Pneumonectomy may be necessary for multiple abscesses unresponsive to drug therapy or for pulmonary gangrene. In patients likely to have difficulty tolerating surgery, percutaneous drainage or, rarely, bronchoscopic placement under ultrasound guidance of a pigtail catheter can help facilitate drainage. . 