What is the normal range for HCO3 in ABGs?

What is the normal range for HCO3 in ABGs?

• A. 22-28 mEq/L
• B. 18-26 mEq/L
• C. 30-34 mEq/L
• D. 12-22 mEq/L

Answer: (A)

In arterial blood gas interpretation, HCO3− is the metabolic component of acid-base balance, reflecting the kidneys’ buffering work. The normal range used for ABG bicarbonate is about 22 to 28 mEq/L. This span accounts for typical biological variation and is the range many clinical references and exams use. Values within this window indicate no primary metabolic abnormality. If HCO3− rises above 28, that suggests metabolic alkalosis or metabolic compensation to a chronic respiratory acidosis; if it falls below 22, that suggests metabolic acidosis or metabolic compensation to a chronic respiratory alkalosis. The broader 22–28 range is preferred over narrower ranges because it better accommodates lab and patient variability.

In arterial blood gas interpretation, HCO3− is the metabolic component of acid-base balance, reflecting the kidneys’ buffering work. The normal range used for ABG bicarbonate is about 22 to 28 mEq/L. This span accounts for typical biological variation and is the range many clinical references and exams use. Values within this window indicate no primary metabolic abnormality. If HCO3− rises above 28, that suggests metabolic alkalosis or metabolic compensation to a chronic respiratory acidosis; if it falls below 22, that suggests metabolic acidosis or metabolic compensation to a chronic respiratory alkalosis. The broader 22–28 range is preferred over narrower ranges because it better accommodates lab and patient variability.