What lab result would the nurse anticipate for a patient with metabolic acidosis?

A. Elevated pH: A high pH (alkalemia) indicates a decrease in hydrogen ion concentration, which is characteristic of alkalosis. Metabolic acidosis is defined by a low arterial pH, typically less than 7.35. The acidic state results from either an accumulation of fixed acids or a loss of base. B. Elevated PaO2: Partial pressure of arterial oxygen measures the amount of oxygen dissolved in the blood and is a marker of oxygenation. It is not a direct component of the acid-base balance equation. While hypoxia can cause metabolic acidosis (via lactic acid), an elevated PaO2 is not a characteristic finding. C. Decreased bicarbonate: Bicarbonate (HCO3-) is the primary buffer in the extracellular fluid. In metabolic acidosis, bicarbonate levels drop as it is consumed while neutralizing excess hydrogen ions or because it is lost through the kidneys or GI tract. A value below 22 mEq/L is a hallmark of this condition. D. Increased PaCO2: An elevated partial pressure of carbon dioxide indicates respiratory acidosis or a compensatory response to metabolic alkalosis. In metabolic acidosis, the body typically tries to compensate by hyperventilating to blow off CO2, which would result in a decreased PaCO2. This is the body's respiratory compensation mechanism.