Final answer:
Bicarbonate (HCO3-) levels increase with metabolic alkalosis and decrease with metabolic acidosis. They are crucial in identifying metabolic imbalances but are less relevant for respiratory disturbances, which are more closely related to CO2 levels.
Step-by-step explanation:
The level that increases in metabolic alkalosis and decreases in metabolic acidosis is bicarbonate (HCO3-).
Bicarbonate levels are indicative of metabolic acid-base disturbances. In metabolic acidosis, the bicarbonate levels decrease due to the relative deficit in HCO3- caused by an excess of acids or loss of base in the body. Conversely, in metabolic alkalosis, there is an excess of bicarbonate, often resulting from a decrease in hydrogen ion concentration or an increase in base intake.
Assessing bicarbonate levels is less useful for respiratory acid/base disturbances because respiratory problems typically affect carbon dioxide (CO2) levels rather than bicarbonate levels directly. However, the kidneys can compensate for respiratory issues by adjusting bicarbonate retention or excretion to maintain acid-base balance.