Geriatric lung abscesses are clinically divided into three types 1. Aspiration lung abscesses Formed by aspiration of oropharyngeal and nasal contents. Among lung abscesses caused by anaerobic bacterial infections, 85% to 90% of cases have risk factors such as inhalation of oral contents or having periodontal disease. Disorders of consciousness (anesthesia, alcohol overdose, use of sedatives, head injury, cerebrovascular accidents and grand mal seizures), swallowing disorders caused by various reasons, destruction of the normal airway defense system after the occurrence of acute neurological diseases, and suppression of the cough reflex can be the cause of aspiration by mistake, and having periodontal disease that changes the quality of oral contents can also be the cause of lung abscess, but there are However, 10% to 15% of patients do not have significant periodontal disease or aspiration risk factors. The site of aspiration lung abscess is related to the anatomical characteristics of the bronchus, as aspirated material moves with gravity and obstructs the bronchus of a lung segment. Because the angle of the left main bronchus is greater than that of the right and the bronchial diameter is thicker, lung abscesses are two times more likely to occur in the right lung than in the left.
twice as likely as the left lung. In the supine position, lung abscesses tend to occur in the dorsal segment of the lower lobe or the posterior segment of the upper lobe, and lung abscesses occurring in these two sites account for 75% of all lung abscess cases. Critically ill patients in intensive care units are prone to lung abscesses caused by Gram-negative bacillus infections in such patients because of the increased colonization of oral Gram-negative bacilli due to the administration of antacids histamine H2-receptor antagonists to prevent stress ulcers. 2.Hematogenous lung abscess Bacteria or emboli in sepsis or septic lesions can reach the lungs via blood circulation, causing embolism of small pulmonary arteries and forming hematogenous lung abscess. It is mostly seen in staphylococcal sepsis, acute purulent osteomyelitis, otitis media, postpartum endometritis and subacute bacterial endocarditis, and also in purulent infections of the face and skin. 3.Secondary lung abscess Certain bacterial pneumonia such as staphylococcal pneumonia, pneumococcal pneumonia, Haemophilus influenzae pneumonia and Legionella pneumonia can develop into cavitary lesions and secondary lung abscess. When a tumor or foreign body obstructs a bronchus, it can cause distal secretion retention and secondary bacterial infection causing lung abscess. Infections of organs near the lungs, such as mediastinitis, liver abscesses, and subdiaphragmatic abscesses that penetrate the diaphragm to the lungs can also cause secondary lung abscesses. The pathology of lung abscess is characterized by local inflammation caused by fine bronchial obstruction, followed by inflammatory embolism of small blood vessels, resulting in rapid necrosis of lung tissue, and after aspiration occurs, 7 to 10
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The abscess is visible on X-ray in 7-10 days after the aspiration. In case of inhalation, the abscess is often solitary and connected to the bronchus; in case of hematogenous, the abscess is multiple and not connected to the bronchus; tension pulmonary pneumocysts caused by Staphylococcus aureus pneumonia are mostly round with thin walls and the surrounding tissue can be squeezed into pulmonary atelectasis. If the abscess occurs on the surface of the lung, it can cause limited fibrinous pleurisy, such as tension abscess breaking into the chest cavity. After treatment, abscess closure mostly forms scar, and if lung abscess is large or improperly treated, scar tissue wrapped abscess cavity is formed, and chronic lung abscess is formed by prolonged treatment. As a result of vascular damage in the abscess wall of lung abscess forming hemangioma, it may cause repeated large or medium amount of hemoptysis; rich granulation tissue vascularity in the abscess wall may also cause small amount of hemoptysis.