Key Points

• Acute lower respiratory infections are a global public health problem, causing significant morbidity and mortality, in addition to a high economic toll.
• Pneumonias are treated based on where it was acquired (community or hospital), severity of illness, comorbidities, and risk factors for atypical or multidrug resistant organisms.
• Empiric treatment of pneumonia is started until culture results are available, at which time antibiotics are tailored to culture-sensitivities.
• For community-acquired pneumonias (CAP), the vast majority are treated on an outpatient basis for five days with a macrolide antibiotic.
• For Hospital-acquired pneumonias (HAP), empiric treatment includes agents with activity against Staphylococcous aureus, Pseudomonas aeruginosa, and other gram-negative bacilli.
• Treatment duration for HAP is at minimum 7 days, with total duration depending upon response to therapy and clinical condition of the patient.
• A multidisciplinary strategy for prevention of ventilator-associated pneumonia (VAP) is recommended that includes non-invasive positive pressure ventilation for able patients, sedation and weaning protocols, head of bed elevation and oral care, and removal of subglottic secretions.
• The most common organisms causing aspiration pneumonia and lung abscesses are oral anaerobes.
• Indications for intervention for lung abscesses include failure of medical therapy, size larger than 4 to 6 cm in diameter, necrotizing infection with multiple abscesses, complications (hemoptysis and rupture into pleural space), and high degree of suspicion for cancer.
• Patients with early empyema should be treated with drainage, patients in the fibrinopurulent stage can be treated with VATS or possibly fibrinolytics, and patients in the organized stage need a decortication to remove the rind and fully re-expand the lung.

Acute lower respiratory tract infections are a worldwide public health problem. For perspective, pneumonias cause a greater burden of disease than HIV, cancer, heart disease or malaria [1]. In the US, they continue to be a major source of morbidity and mortality over any other infection. Despite advances in the field of medicine, there has been little change in mortality due to respiratory tract infection over the past five decades [1],[2]. The goal of this chapter is to detail the diagnostic work-up and treatment for three conditions in adults – pneumonia, lung abscess and empyema – with a focus on the pragmatic approach for the Thoracic surgeon.