Medical Surgical ABGs & Acid Base Imbalances #2

Question

A client is admitted to the ER with confusion, restlessness, and diaphoresis. Lab studies reveal pH 7.1, PCO2 48, and a potassium of 5.6. Which acid-base balance disorder does the data collected indicate?

Answers

  1. Respiratory acidosis
    • Rationale:

      This answer is correct because the client’s labs indicate that the body is retaining carbon dioxide, making the body more acidic by decreasing the blood pH. This is also evidenced by the client’s symptoms of confusion, restlessness, and diaphoresis. Hyperkalemia occurs as a result of the low blood pH which shifts potassium out of the cells and into extracellular fluid.

  2. Respiratory alkalosis
    • Rationale:

      This answer is not correct since the labs or symptoms do not represent respiratory alkalosis. Respiratory alkalosis occurs when the pH of the blood rises and becomes too alkaline and potassium moves from the extracellular fluid into the cells.

  3. Metabolic acidosis
    • Rationale:

      This answer is not correct because the labs indicate the PaCO2 is increased. In metabolic acidosis, the PaCO2 will be normal or decreased.

  4. Metabolic alkalosis.
    • Rationale:

      This answer is not correct because the labs show that the pH of the blood is decreased. In metabolic alkalosis, the pH will be increased.

Overview

Respiratory acidosis is when the lungs cannot remove enough carbon dioxide causing the blood pH to decrease below 7.35 and the partial pressure of CO2 to increase above 45. Symptoms include restlessness, mental status changes, diaphoresis, cyanosis, and hyperkalemia.

Explanation

Learning Outcomes

Respiratory acidosis is when the lungs cannot remove enough carbon dioxide causing the blood pH to decrease below 7.35 and the partial pressure of CO2 to increase above 45. Symptoms include restlessness, mental status changes, diaphoresis, cyanosis, and hyperkalemia. Respiratory alkalosis occurs when the pH of the blood rises and becomes too alkaline and potassium moves from the extracellular fluid into the cells. This will show an increase in pH and a decrease in PCO2. The potassium value will decrease. In metabolic acidosis, the PaCO2 will be normal or decreased and the potassium will be increased. In metabolic alkalosis, the pH will be increased.

Test Taking Tip

Know your arterial blood gas values: The pH will be decreased in respiratory and metabolic acidosis and will be increased in respiratory alkalosis and metabolic alkalosis. In the PCO2/HCO3, the respiratory will be opposite and the metabolic will be equal. Remember: ROME (Respiratory Opposite, Metabolic Equal).

Video Rationale