Respiratory Flashcards

Question

Sarcoidosis

Answer 1

Systemic disease characterized by noncaseating granulomas in multiple organs; classically seen in African American females Etiology is unknown; likely due to CD4+ helper T-cell response to an unknown antigen Granulomas most commonly involve the hilar lymph nodes and lung leading to restrictive lung disease. * Characteristic stellate inclusions ('asteroid bodies') are often seen within giant cells of the granulomas Other commonly involved tissues include the uvea (uveitis), skin (cutaneous nodules or erythema nodosum), and salivary and lacrimal glands (mimics Sjogren syndrome); almost any tissue can be involved) Clinical features 1. Dyspnea or cough (most common presenting symptom) 2. Elevated serum ACE 3. Hypercalcemia (1-alpha hydroxylase activity of epithelioid histiocytes converts vitamin D to its active form) 4. Treatment is steroids; often resolves spontaneously without treatment.

Answer 2

* Exposure to carbon dust; seen in coal miners * Massive exposure leads to diffuse fibrosis ('black lung'); associated with rheumatoid arthritis (Caplan syndrome) * Mild exposure to carbon (e.g., pollution) results in anthracosis (collections of carbon-laden macrophages); not clinically significant)

Answer 3

* Exposure: silica, seen in sand blaster and silica miners * Pathologic Finding: Fibrotic nodules in upper lobes of the lung * Increased risk for TB; silica impairs phagolysosome formation by macrophages.

Answer 4

* Exposure: Beryllium, seen in beryllium miners and workers in the aerospace industry * Pathologic finding: Noncaseating granulomas in the lung, hilar lymph nodes, and systemic organs * Increased risk for lung cancer

Answer 5

* Exposure: Asbestos fibers; seen in construction workers, plumbers, and shipyard workers * Pathologic Finding: Fibrosis of lung and pleura [plaques) with increased risk for lung carcinoma and mesothelioma; lung carcinoma is more common lhan mesothelioma in exposed individuals. * Lesions may contain long, golden- brown fibers with associated iron (asbestos bodies), which confirm exposure to asbestos

Answer 6

* Granulomatous reaction to inhaled organic antigens (e.g., pigeon breeder's lung) * Presents with fever, cough, and dyspnea hours after exposure; resolves with removal of the exposure * Chronic exposure leads to interstitial fibrosis.

Answer 7

High pressure in the pulmonary circuit (mean arterial pressure \> 25 mm Hg; normal is 10 mm Hg) Characterized by atherosclerosis of the pulmonary trunk, smooth muscle hypertrophy of pulmonary arteries, and intimal fibrosis; plexiform lesions are seen with severe, long-standing disease Leads to right ventricular hypertrophy with eventual cor pulmonale D. Presents with exertional dyspnea or right-sided heart failure Subclassified as primary or secondary based on etiology PRIMARY PULMONARY HYPERTENSION * Classically seen in young adult females * Etiology is unknown; some familial forms are related to inactivating mutations of BMPR2, leading to proliferation of vascular smooth muscle. SECONDARY PULMONARY HYPERTENSION * Due to hypoxemia (e.g., COPD and interstitial lung disease) or increased volume in the pulmonary circuit (e.g., congenital heart disease); may also arise with recurrent pulmonary embolism

Answer 8

Diffuse damage to the alveolar-capillary interface (diffuse alveolar damage) Leakage of protein-rich fluid leads to edema and formation of hyaline membranes in alveoli Clinical features * Hypoxemia and cyanosis with respiratory distress—due to thickened diffusion barrier and collapse of air sacs (increased surface tension) * 'White-out' on chest x-ray Secondary to a variety of disease processes including sepsis, infection, shock, trauma, aspiration, pancreatitis, DIG, hypersensitivity reactions, and drugs. * Activation of neutrophils induces protease-mediated and free radical damage of type 1 and II pneumocytes Treatment * Address underlying cause * Ventilation with positive end-expiratory pressure (PEEP) Recovery may be complicated by interstitial fibrosis; damage and loss of type 11 pneumocytes leads to scarring and fibrosis.

Answer 9

Respiratory distress due to inadequate surfactant levels * Surfactant is made by type II pneumocytes; phosphatidylcholine (lecithin) is the major component. * Surfactant decreases surface tension in the lung, preventing collapse of alveolar air sacs after expiration. * Lack of surfactant leads to collapse of air sacs and formation of hyaline membranes. Associated with * Prematurity—Surfactant production begins at 28 weeks; adequate levels are not reached until 34 weeks. * Amniotic fluid lecithin to sphingomyelin ratio is used to screen for lung maturity. * Phosphatidylcholine (lecithin) levels increase as surfactant is produced; sphingomyelin remains constant. A ratio \> 2 indicates adequate surfactant production. * Caesarian section delivery—due to lack of stress-induced steroids; steroids increase synthesis of surfactant, * Maternal diabetes—Insulin decreases surfactant production, and grunting Clinical features * Increasing respiratory effort after birth, tachypnea with use of accessory muscles * Hypoxemia with cyanosis * Diffuse granularity of the lung ('ground-glass' appearance) on x-ray Complications * Hypoxemia increases the risk for persistence of patent ductus arteriosus and necrotizing enterocolitis. * Supplemental oxygen increases the risk for free radical injury. Retinal injury leads to blindness; lung damage leads to bronchopulmonary dysplasia

Answer 10

Most common cause of cancer mortality in the US; average age at presentation is 60 years. Key risk factors are cigarette smoke, radon, and asbestos. * Cigarette smoke contains over 60 carcinogens; 85% of lung cancer occurs in smokers, * Polycyclic aromatic hydrocarbons and arsenic are particularly mutagenic. * Cancer risk is directly related to the duration and amount of smoking ('pack-years'). Radon is formed by radioactive decay of uranium, which is present in soil. * Accumulates in closed spaces such as basements * Responsible for most of the public exposure to ionizing radiation; 2nd most frequent cause of lung carcinoma in US * Increased risk of lung cancer is also seen in uranium miners. Presenting symptoms are nonspecific (e.g., cough, weight loss, hemoptysis, and postobstructive pneumonia). Imaging often reveals a solitary nodule ('coin-lesion'); biopsy is necessary for a diagnosis of cancer * Benign lesions, which often occur in younger patients, can also produce a 'coin- lesion * Examples include * Granuloma—often due to TB or fungus (especially Hittoplasma in the Midwest) * Bronchial hamartoma—benign tumor composed of lung tissue and cartilage; olien calcified on imaging TNM staging 1. T—Tumor size and local extension * Pleural involvement is classically seen with adenocarcinoma, * Obstruction ofSVC leads to distended head and neck veins with edema and blue discoloration of arms and face (superior vena cava syndrome). * Involvement of recurrent laryngeal (hoarseness) or phrenic (diaphragmatic paralysis) nerve * Compression of sympathetic chain leads to Horner syndrome characterized by ptosis (drooping eyelid), miosis (pinpoint pupil), and anhidrosis (no sweating); usually due to an apical (Pancoast) tumor 2. N—spread to regional lymph nodes (hilar and mediastinal) 3. M—unique site of distant metastasis is the adrenal gland. Overall, 15% 5-year survival; often presents late due to the absence of an effective screening method

Answer 11

Accumulation of air in the pleural space Spontaneous pneumothorax is due to rupture of an emphysematous bleb; seen in young adults * Results in collapse of a portion of the lung (Fig. 9.24); trachea shifts to the side of collapse. Tension pneumothorax arises with penetrating chest wall injury. * Air enters the pleural space, but cannot exit; trachea is pushed opposite to the side of injury. * Medical emergency; treated with insertion of a chest tube

Answer 12

Malignant neoplasm of mesotheiial cells; highly associated with occupational exposure to asbestos Presents with recurrent pleural effusions, dyspnea, and chest pain; tumor encases the lung

Respiratory Flashcards

(36 cards)