Ch 5 Practice Q's

A 56-year-old man with a 40-pack-year smoking history presents with progressive dyspnea, a barrel-shaped chest, and diminished breath sounds. ABG shows PaO2 58 mmHg, PaCO2 52 mmHg, and pH 7.35. Which pathophysiologic change most directly explains his CO2 retention?

• Increased respiratory drive from hypoxemia

• Loss of elastic recoil reducing expiratory airflow and trapping gas

• Increased surfactant production causing airway collapse

• Impaired diffusion capacity from pulmonary embolism

A 3-year-old child presents with fever, drooling, inspiratory stridor, and sitting in a tripod position. Which immediate intervention is most critical before diagnostic testing?

• Administer nebulized epinephrine

• Obtain a throat culture

• Secure the airway to prevent complete obstruction

• Give IV corticosteroids

A patient presents with severe dyspnea, hypotension, and absent breath sounds on the right after a motor vehicle accident. Trachea is deviated to the left. Which mechanism is causing the hemodynamic instability?

• Increased pulmonary vascular resistance

• Increased intrathoracic pressure compressing vena cava and reducing preload

• Decreased compliance from surfactant loss

• V/Q mismatch from alveolar consolidation

A 48-year-old man with COPD develops worsening hypoxemia after starting high-flow supplemental oxygen. Which mechanism best explains this paradoxical drop in oxygenation?

• Oxygen toxicity causing alveolar damage

• Reduced hypoxic pulmonary vasoconstriction increasing V/Q mismatch

• Increased oxygen binding affinity reducing tissue delivery

• CO₂ displacement from hemoglobin increasing acidity

A 60-year-old woman develops acute respiratory distress syndrome (ARDS) after sepsis. Chest X-ray shows bilateral infiltrates. Which primary pathophysiologic event leads to her hypoxemia?

• Bronchospasm narrowing small airways

• Increased alveolar-capillary membrane permeability causing non-cardiogenic pulmonary edema

• Alveolar destruction reducing surface area

• Microthrombi obstructing pulmonary vessels

A patient with a history of tuberculosis presents with hemoptysis, night sweats, and weight loss. Which cellular process is primarily responsible for lung tissue destruction in this disease?

• Neutrophil elastase release

• Caseating granulomatous inflammation from T-cell–mediated macrophage activation

• Apoptosis of type II alveolar cells

• Surfactant inactivation by bacterial toxins

A 19-year-old man with cystic fibrosis presents with increased cough, purulent sputum, and fever. Which mechanism most directly contributes to his recurrent infections?

• Loss of IgA secretion in respiratory tract

• Increased elastase activity in alveolar macrophages

• Defective chloride transport leading to thick, dehydrated mucus

• Hypersensitivity reaction to bacterial antigens

A patient with pneumonia has a PaO2 of 55 mmHg despite receiving 100% oxygen. Which abnormality best explains this finding?

• Low V/Q mismatch

• Right-to-left shunt from alveoli completely filled with exudate

• Dead space ventilation from embolism

• Increased diffusion distance in alveolar walls

A 7‑year‑old child presents with wheezing, chest tightness, and cough triggered by pollen exposure. Which mediator is most responsible for his acute bronchoconstriction?

• IL‑- 5

• TNF - a

• Histamine released from mast cells

• Platelet-activating factor

A 52‑year‑old man presents with progressive exertional dyspnea. Pulmonary function tests show a restrictive pattern with reduced lung volumes. Which finding best distinguishes this from an obstructive disorder?

• Decreased FEV₁/FVC ratio

• Increased total lung capacity

• Normal or increased FEV₁/FVC ratio

• Increased residual volume