Question

Choose two infectious disease processes that either affect ventilation, oxygenation or perfusion. Describe in detail how the infectious process affects the lungs in each selected disease process. Focus on how the infections can cause problems with ventilation, gas exchange/diffusion across the alveoli, and oxygenation. Of the two infectious disease processes chosen, list the risk factors for each that predispose the patient to the infectious disease process. What are the complications of each disease process if left untreated?

Answer 1

Thr lungs are most vulnerable organs because it has direct external contact by the air that flows through it.

Knowledge of the radiologic pattern of infectious lung disease in a given patient often helps to narrow the scope of the differential diagnosis.

Fortunately the recognized histopathologic patterns of lung infection are fairly limited (airway disease, acute lung injury, cellular infiltrates, alveolar filling, and nodules), and these typically correlate with a particular group of organisms.

Tuberculosis maybe the most important disease but fungal agents causes Histoplasmosis.

Histoplasmosis is a pulmonary and systemic infection that is caused by infective spores (fungi), most commonly found in the soil of the central and eastern United States. Histoplasmosis is transmitted by inhalation of dust from the soil or bird and bat feces. The spores form lesions within the lung parenchyma that can be spread to other tissues. The incidence of fungal infection is rising, particularly in immunocompromised, immunosuppressed, and chronically debilitated individuals who may also be receiving corticosteroid, antineoplastic, and multiple antibiotic therapy.

Different clinical forms of histoplasmosis are (1) acute, benign respiratory disease, which results in flulike illness and pneumonia; (2) acute disseminated disease, which can result in septic-type fever; (3) chronic disseminated disease, which involves lesions in the bone marrow, spleen, and lungs and can result in immunodeficiency; and (4) chronic pulmonary disease, which manifests as progressive emphysema.

Management of histoplasmosis may include the following

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Antiinfective agents

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Corticosteroids

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Antihistamines

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Antifungal therapy

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Supportive care appropriate for affected areas in the various forms of histoplasmosis.

Tuberculosis mostly occurs in the right lung coz of the bronchus is shorter and broader.

The aerobic bacteria needs an oxygen rich environment so right lung upper pole has a low ventilation perfusion ratio so the oxygen is present more. Aerobic bacteris easily grow in upper pole.

Tuberculosis bacilli thus has a site of lower part of upper pole and upper part of lower pole.

Damages the parenchyma of lungs and disturbs alveolar gas exchange.

complications- Tuberculosis may manifest whole body organs. So dangerous. Also lung parenchyma forms ghon complex. Lungs get damaged so need to be dissected.