The hallmark manifestation of acute respiratory distress syndrome (ARDS) is:

• A. Severe hypoxemia that is refractory to oxygen therapy
• B. Wheezing and bronchospasm
• C. Chronic hypercapnia
• D. Productive cough with purulent sputum

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the condition described in the problem, Acute Respiratory Distress Syndrome (ARDS). ARDS is a severe lung condition characterized by widespread inflammation and fluid accumulation in the alveoli, leading to impaired gas exchange.
2. Step 2: Review the hallmark manifestation of ARDS. The key feature of ARDS is severe hypoxemia (low blood oxygen levels) that does not improve with supplemental oxygen therapy. This occurs because the alveoli are filled with fluid, preventing oxygen from effectively diffusing into the bloodstream.
3. Step 3: Analyze the options provided in the problem. Severe hypoxemia refractory to oxygen therapy aligns with the hallmark manifestation of ARDS. The other options, such as wheezing and bronchospasm, chronic hypercapnia, and productive cough with purulent sputum, are more characteristic of other respiratory conditions like asthma, chronic obstructive pulmonary disease (COPD), or pneumonia.
4. Step 4: Eliminate incorrect options based on the pathophysiology of ARDS. Wheezing and bronchospasm are typically associated with airway obstruction, not ARDS. Chronic hypercapnia (elevated CO2 levels) is more common in chronic respiratory diseases. A productive cough with purulent sputum is indicative of infection, such as pneumonia, rather than ARDS.
5. Step 5: Conclude that the hallmark manifestation of ARDS is severe hypoxemia that is refractory to oxygen therapy, as this is the defining feature of the condition based on its pathophysiology.