From the Guidelines
The average bicarbonate level in the blood should be maintained between 22 and 29 milliequivalents per liter (mEq/L) or 22-29 mmol/L, with treatment aimed at keeping levels within this normal range, especially in patients with chronic kidney disease (CKD) or those at risk of metabolic acidosis, as indicated by the most recent guideline 1.
Normal Bicarbonate Range
The normal bicarbonate concentration in the bloodstream for healthy adults is between 22 and 29 mmol/L. This range is crucial for maintaining proper pH balance, with bicarbonate serving as a key buffer in the body to neutralize acids. The kidneys and lungs work together to regulate bicarbonate levels, with the kidneys retaining or excreting bicarbonate and the lungs controlling carbon dioxide levels, which affects bicarbonate through the carbonic acid-bicarbonate buffer system.
Importance of Monitoring Bicarbonate Levels
Regular monitoring of bicarbonate levels is important, particularly for patients with kidney disease, respiratory conditions, or those taking medications that affect acid-base balance. Significant deviations from the normal range require medical attention, as they can indicate serious underlying health issues affecting the body's acid-base homeostasis. Levels below 22 mEq/L may indicate metabolic acidosis, while levels above 29 mEq/L could suggest metabolic alkalosis.
Treatment of Metabolic Acidosis
According to the most recent guideline 1, acidosis in adults should only be treated with pharmacologic agents when bicarbonate < 18 mmol/l or if there is a clear indication to do so. A reasonable goal would be to increase bicarbonate levels toward but not greater than the normal range with sodium bicarbonate or other agents. This approach is supported by previous guidelines, which suggest treating metabolic acidosis to maintain serum bicarbonate within the normal range, unless contraindicated 1.
Key Considerations
- Maintaining Normal Bicarbonate Levels: The goal is to keep bicarbonate levels within the normal range (22-29 mmol/L) to prevent complications associated with metabolic acidosis or alkalosis.
- Monitoring and Treatment: Regular monitoring and appropriate treatment, such as oral bicarbonate supplementation, are crucial for managing patients with CKD or at risk of metabolic acidosis.
- Recent Guidelines: The most recent guideline 1 provides updated recommendations on the treatment of metabolic acidosis, emphasizing the importance of maintaining bicarbonate levels within the normal range.
From the FDA Drug Label
Plasma concentration is regulated by the kidney through acidification of the urine when there is a deficit or by alkalinization of the urine when there is an excess. Bicarbonate (HCO3-) is a normal constituent of body fluids and the normal plasma level ranges from 24 to 31 mEq/liter The average bicarbonate level is between 24 and 31 mEq/liter 2.
- The normal range for plasma bicarbonate level is 24-31 mEq/liter.
- This range is applicable to a healthy adult with normal kidney function.
From the Research
Average Bicarbonate Levels
- The average bicarbonate level is not explicitly stated in the provided studies, but target values for predialysis serum bicarbonate concentration have been established primarily based on observational studies and expert opinion 3.
- According to 3, the predialysis serum bicarbonate level should be kept at least at 22 mmol/l.
- A study published in 4 found that serum bicarbonate showed a significant U-shaped association with all-cause mortality, with the highest mortality rate observed in patients with baseline serum bicarbonate levels <22 mmol/L.
- The same study 4 found that the lowest mortality was observed in patients with baseline serum bicarbonate of 26-29 mmol/L.
Bicarbonate Levels and Mortality
- Lower serum bicarbonate levels are associated with increased all-cause mortality in patients with moderate and advanced non-dialysis-dependent CKD 4.
- Higher serum bicarbonate levels are also associated with increased all-cause mortality in patients with moderate and advanced non-dialysis-dependent CKD 4.
- Treatment of metabolic acidosis with sodium bicarbonate improves kidney and patient survival in patients with CKD stages 3-5 5.
Bicarbonate Supplementation
- Sodium bicarbonate supplementation can increase serum bicarbonate levels and improve kidney function in patients with CKD 5, 6.
- Sodium citrate and sodium bicarbonate have similar effects on kidney function decline and serum bicarbonate levels, but sodium bicarbonate is associated with higher rates of medication discontinuation due to adverse events 6.