What condition is indicated by a pH of 7.28 and HCO3 of 18 mEq/L?

A pH of 7.28 indicates that the blood is more acidic than the normal range (which is 7.35-7.45), and this low pH suggests a state of acidosis. The bicarbonate (HCO3) level of 18 mEq/L is also below the normal range (22-26 mEq/L), further supporting the diagnosis of acidosis because bicarbonate is a base that helps to buffer the acidity in the blood.

In metabolic acidosis, the primary issue is a decrease in bicarbonate, which is exactly what is observed here with the HCO3 being at 18 mEq/L. This decrease leads to an acidotic state in the body, resulting in the blood pH dropping below the normal range.

The presence of a low pH combined with a low bicarbonate level distinctly points to metabolic acidosis. Other conditions such as metabolic alkalosis or respiratory acidosis would not typically present with these specific lab values. Metabolic alkalosis would show elevated pH and increased HCO3, while respiratory acidosis would typically demonstrate a low pH with an elevated level of carbon dioxide (CO2), rather than a decrease in bicarbonate alone.

Therefore, the combination of a low p