Fluid & Electrolyte Q 54

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The presence of which of the following electrolytes contributes to acidosis?

  

    A. Sodium

    B. Potassium

    C. Hydrogen

    D. Chloride

    

    

Correct Answer: C. Hydrogen

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The presence of hydrogen ions determines a solution’s acidity. Acidosis is defined as an abnormal clinical process that causes a net gain in hydrogen ions (H+) in the extracellular fluid. Metabolic acidosis occurs when there is an accumulation of H+ or a loss of bicarbonate ions (HCO3?) and is reflected by a decrease in plasma HCO3? (<22 mEq/L).

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Option A: Adrenocortical insufficiency that occurs in Addison’s disease causes hyponatremia and renal tubular acidosis (RTA). Hyponatremia results from both aldosterone and cortisol insufficiency. RTA is due to aldosterone insufficiency.

Option B: A frequently cited mechanism for these findings is that acidosis causes potassium to move from cells to extracellular fluid (plasma) in exchange for hydrogen ions, and alkalosis causes the reverse movement of potassium and hydrogen ions.

Option D: An increased plasma chloride ion concentration relative to sodium and potassium concentrations will produce a smaller plasma strong ion difference, leading to an increased hydrogen ion concentration, and therefore acidosis.

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