In Metabolic Acidosis there is -

Appeared in: UPPSC 2023

Explanation

Metabolic acidosis is fundamentally defined by a primary decrease in the body's main buffer, bicarbonate (HCO₃⁻), or an increase in metabolic acids.
The loss of bicarbonate directly lowers the blood's buffering capacity, causing the pH to become more acidic.
A classic cause of bicarbonate loss is severe diarrhea, where large amounts of bicarbonate-rich fluid are expelled from the gastrointestinal tract.

Option B: In metabolic acidosis due to bicarbonate loss, chloride is retained by the kidneys to maintain electroneutrality, leading to hyperchloremia (increased chloride), not a decrease.
Option C: While sodium loss can occur concurrently in conditions like diarrhea, it is not the primary cause or defining characteristic of metabolic acidosis. The critical change is the loss of the bicarbonate buffer.
Option D: Metabolic acidosis causes a shift of potassium from inside the cells to the bloodstream in exchange for hydrogen ions, leading to hyperkalemia (increased potassium), not a loss.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of metabolic acidosis as background academic context rather than a clinical decision trigger.
Nurses must closely monitor Arterial Blood Gas (ABG) results to identify metabolic acidosis (low pH, low HCO₃⁻) and track the patient's response to treatment.
A critical nursing assessment is monitoring for signs of hyperkalemia (e.g., ECG changes like peaked T-waves, muscle weakness, dysrhythmias), a life-threatening complication of metabolic acidosis.
Rapid correction of acidosis with bicarbonate can cause a sudden shift of potassium back into cells, leading to severe hypokalemia. Therefore, potassium levels must be monitored carefully during treatment.

How to Approach the Question

First, identify the core concept in the question stem, which is 'Metabolic Acidosis'.
Recall the definition of this acid-base imbalance. 'Metabolic' points to a problem with bicarbonate (HCO₃⁻), and 'acidosis' means a state of excess acid (low pH).
Therefore, the primary problem in metabolic acidosis is either a gain of acid or a loss of base (bicarbonate).
Evaluate the options based on this core principle. 'Excessive loss of Bicarbonates' directly aligns with the pathophysiology.
Systematically eliminate the other options by recalling the associated electrolyte changes in acidosis: potassium levels typically rise (hyperkalemia), and in cases of bicarbonate loss, chloride levels also rise (hyperchloremia).

Concept Tested & Keywords

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E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart A (pp 1-239 of 478) p. 82-84

E6 Nursing Fundamentals Potter Perry 12e Part 5 p. 56-58

E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 69-71

Practise the full UPPSC 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.