[Pulmonary suppuration]

Pulmonary suppuration is defined as necrosis of the pulmonary parenchyma caused by microbial infection. Pulmonary suppuration may be primary or secondary based upon the presence or absence of common associated conditions. Abscesses in patients prone to aspiration are usually considered primary; the term secondary lung abscess typically indicates an associated bronchogenic neoplasm or systemic disease that compromises immune defenses, such as the acquired immunodeficiency syndrome (AIDS) or organ transplantation. In 70 to 90% of cases it is caused by anaerobic bacteria or by co-infection of anaerobic and aerobic bacterium. Thus, pulmonary suppuration is treated with antibiotics, which leads to recovery from the disease in at least 80% of cases. For patients who do not respond to antibiotic administration or those with secondary pulmonary suppuration (particularly following primary lung cancer), surgical resection or percutaneous transthoracic drainage (PTD) are the procedures of choice. Although surgery leads to good recovery rates, the risk of developing post-operative complications and mortality are also elevated. Unlike surgical resection, performing PTD provokes little loss of pulmonary function and therefore, it should be recommended to high risk patients who cannot undergo lung resection.