Acute acidosis in the neonate often results in which electrolyte disturbance?

• A. Hypokalemia
• B. Hyperkalemia
• C. Hyponatremia
• D. Hyperchloremia

Answer: (B)

Acute acidosis causes potassium to shift from the inside of cells to the outside. When hydrogen ions accumulate in the blood, cells exchange H+ for other cations like potassium to help balance charge, so potassium leaves the cells and rises in the extracellular fluid. In neonates, immature kidneys are less able to excrete this extra potassium, so serum potassium tends to become elevated. This combination makes hyperkalemia the typical electrolyte disturbance seen with acute acidosis in newborns. Hyponatremia isn’t a direct consequence of acidosis, and while some acid-base states can involve changes in chloride, the most characteristic shift with acute acidosis is an increase in potassium.