A person with emphysema will exhibit signs of
Group of answer choices
chronic metabolic acidosis.
chronic respiratory acidosis.
chronic respiratory alkalosis.
acute respiratory acidosis.
metabolic alkalosis.
The Correct Answer and Explanation is :
The correct answer is:
Chronic respiratory acidosis.
Explanation:
Emphysema is a chronic lung disease that falls under the umbrella of chronic obstructive pulmonary disease (COPD). It is characterized by the destruction of alveolar walls, leading to reduced surface area for gas exchange and air trapping in the lungs. As a result, the primary problem in emphysema is impaired exhalation, which leads to the retention of carbon dioxide (CO₂) in the blood.
Why Chronic Respiratory Acidosis?
- CO₂ Retention:
- In a healthy person, CO₂ is efficiently expelled from the lungs. However, in emphysema, damaged alveoli reduce lung elasticity, making it difficult to fully exhale. This leads to the accumulation of CO₂ in the bloodstream (hypercapnia).
- pH Imbalance:
- The body maintains pH balance (7.35–7.45) by regulating CO₂ (respiratory system) and bicarbonate (HCO₃⁻) (renal system). CO₂ reacts with water to form carbonic acid (H₂CO₃), which lowers blood pH, causing respiratory acidosis.
- Chronic Compensation:
- Because emphysema is a long-term condition, the kidneys try to compensate by increasing bicarbonate (HCO₃⁻) reabsorption to neutralize the acidic pH. However, this compensation is not perfect, and the patient remains in a state of chronic respiratory acidosis.
Why Not the Other Choices?
- Chronic metabolic acidosis: This results from kidney disease, diabetic ketoacidosis, or severe diarrhea—not CO₂ retention.
- Chronic respiratory alkalosis: Would occur if the patient hyperventilates and expels too much CO₂, which is not the case in emphysema.
- Acute respiratory acidosis: Emphysema is chronic, not acute. Acute cases happen with sudden lung failure or airway obstruction.
- Metabolic alkalosis: This occurs due to vomiting or excessive bicarbonate intake, unrelated to emphysema.
Thus, chronic respiratory acidosis is the correct answer.