Lung abscess is least likely a complication of

Lung abscess can be divided on acute (less than 6 weeks) and chronic (more than 6 weeks). It can be called primary as a result of aspiration of oropharyngeal secretions (dental/periodontal infection, para nasal sinusitis, disturbance states of consciousness, swelling disorders, gastro-oesophageal reflux disease, frequent vomiting, necrotizing pneumonia's or in immunocompromised patients. Secondary lung abscesses occurred in bronchial obstructions (by tumor, foreign body or enlarged lymph nodes), with coexisting lung diseases (bronchiectasis, bullous emphysema, cystic fibrosis, infected pulmonary infarcts, lung contusion), then spreading from extrapulmonary sites-hematogenous (abdominal sepsis, infective endocarditis, infected canula or central venous catheter, septic thromboembolisms) or by direct spreading (broncho-oesophageal fistula, subphrenic abscess) (6). Based on way of spreading, lung abscess can be bronchogenic (aspiration, inhalation) and haematogenic-dissemination from other infected sites. Division of lung abscesses: According to the duration: Acute (less than 6 weeks); Chronic (more than 6 weeks); By etiology: Primary (aspiration of oropharyngeal secretions, necrotizing pneumonia, immunodeficiency); Secondary (bronchial obstructions, haematogenic dissemination, direct spreading from mediastinal infection, from subphrenium, coexisting lung diseases); Way of spreading: Brochogenic (aspiration of oropharyngeal secretions, bronchial obstruction by tumor, foreign body, enlarged lymph nodes, congenital malformation); Haematogenic (abdominal sepsis, infective endocarditis, septic thromboembolisms). Ref Davidson edition23rd pg 584