The cause for respiratory acidosis among the following is:

AIIMS BHOPAL NO- 2018( Shift-2nd)

Medical & Surgical Nursing

Medium

Appeared in: AIIMS BHOPAL NO- 2018( Shift-2nd)

Explanation

Respiratory acidosis is defined by hypoventilation (inadequate breathing), which prevents the body from expelling enough carbon dioxide (CO₂).
A respiratory obstruction, such as from a foreign object, severe asthma, or COPD, physically blocks the airways, impairing exhalation.
This blockage traps CO₂ in the blood, a condition called hypercapnia. The excess CO₂ increases carbonic acid levels and lowers the blood's pH, leading to acidosis.

Option A: This causes respiratory alkalosis. Rapid, deep breathing ('hyperventilation') blows off too much CO₂, decreasing its level in the blood and raising the pH.
Option B: This causes metabolic alkalosis. The loss of stomach acid (hydrochloric acid) through vomiting leads to a relative increase in bicarbonate in the blood, raising the pH.
Option D: This causes metabolic acidosis. In the absence of sufficient insulin, the body breaks down fats for energy, producing acidic byproducts called ketone bodies. Their accumulation lowers blood pH.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of Respiratory Acidosis as background academic context rather than a clinical decision trigger.
Nurses must quickly identify the cause of respiratory acidosis to provide life-saving interventions, such as clearing an airway, administering bronchodilators, or preparing for mechanical ventilation.
A key safety consideration is oxygen administration in patients with chronic respiratory acidosis (like COPD). Their respiratory drive is often stimulated by low oxygen (hypoxic drive), not high CO2. Giving too much oxygen can suppress their drive to breathe, worsening the acidosis.
What if? If the patient had Kussmaul respirations (deep, rapid breathing) and a fruity odor on their breath, the cause would likely be Diabetic Ketoacidosis (Metabolic Acidosis), and the priority would be insulin administration and fluid replacement, not airway management for obstruction.

How to Approach the Question

First, break down the question: it asks for a cause of 'respiratory acidosis'.
Recall the core mechanism: 'Respiratory' refers to the lungs and CO₂. 'Acidosis' means too much acid (low pH). Therefore, respiratory acidosis is caused by the lungs retaining too much CO₂.
Analyze each option based on its effect on CO₂ or body acids.
Option A (Hyperventilation): 'Hyper' means over-breathing. This would blow off CO₂, causing alkalosis. Incorrect.
Option B (Vomiting): This is a gastrointestinal issue involving loss of stomach acid. This is a 'metabolic' problem, not respiratory. Incorrect.
Option C (Respiratory obstruction): An obstruction would prevent breathing out, thus trapping CO₂. This directly matches the pathophysiology of respiratory acidosis. Correct.

Concept Tested & Keywords

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