Critical Care Paramedic Practice Exam

When the bicarbonate (HCO3) level is below 22 mEq/L, it typically indicates acidosis. The bicarbonate level is a crucial component of the body's acid-base balance, and it serves as a buffer against acids. A low level of bicarbonate suggests an excess of hydrogen ions or other acids in the bloodstream, leading to a state of acidosis.

In the context of acidosis, there are two main types: metabolic acidosis and respiratory acidosis. Metabolic acidosis is characterized by a direct decrease in bicarbonate due to conditions such as kidney failure, diabetic ketoacidosis, or lactic acidosis. In respiratory acidosis, while bicarbonate levels may eventually decline in compensation, the initial cause is usually elevated carbon dioxide levels due to inadequate ventilation.

This reduction in bicarbonate reflects the body’s attempt to correct an existing acidotic state or may indicate an accumulation of acids due to metabolic processes. Therefore, a low HCO3 level is commonly associated with acidosis, confirming that the interpretation of a level below 22 mEq/L points towards an acid-base disturbance requiring further evaluation and management.