PAEA Surgery End Of Rotation (EOR) Practice Exam

What does HCO3 loss typically lead to in terms of acidosis or alkalosis?

1. Respiratory alkalosis

2. Metabolic acidosis

3. Respiratory acidosis

4. Metabolic alkalosis

The correct answer is: Metabolic acidosis

Loss of HCO3, or bicarbonate, typically results in metabolic acidosis. Bicarbonate acts as a primary buffer in the body's acid-base balance; it helps to neutralize acids and maintain a stable pH level. When there is a loss of bicarbonate, either through gastrointestinal losses (like diarrhea) or renal losses, it leads to a decrease in the bicarbonate concentration in the blood. This decrease causes a relative increase in hydrogen ion concentration, which decreases the pH of the blood, indicating acidosis. In contrast, respiratory alkalosis occurs primarily due to hyperventilation, which decreases carbon dioxide levels and increases pH. Respiratory acidosis is a result of hypoventilation, leading to increased carbon dioxide and lower pH. Metabolic alkalosis is related to an increase in bicarbonate or a loss of acid that raises the pH. Thus, the specific loss of HCO3 directly correlates with the development of metabolic acidosis.