HCO3-, Arterial

Decreased levels of HCO3- (bicarbonate) in arterial blood, known as metabolic acidosis, indicate an excess of acid in the body or a loss of bicarbonate. This condition disrupts the body's normal acid-base balance and can result from several underlying causes:

1. Diabetic Ketoacidosis (DKA): In uncontrolled diabetes, the body breaks down fat for energy, producing ketones, which are acidic, leading to a decrease in bicarbonate levels.

2. Chronic Kidney Disease: The kidneys are unable to excrete enough acid or retain sufficient bicarbonate, leading to metabolic acidosis.

3. Lactic Acidosis: Caused by an accumulation of lactic acid in the blood, often due to conditions like sepsis, shock, or intense exercise, which overwhelms the buffering capacity of bicarbonate.

4. Diarrhea: Severe diarrhea can lead to the loss of bicarbonate from the digestive tract, causing a decrease in bicarbonate levels.

5. Toxic Ingestion: Ingesting substances like methanol, ethanol, or salicylates (aspirin) can increase the production of acid in the body, lowering bicarbonate levels.

6. Starvation or Malnutrition: Prolonged fasting or inadequate food intake can lead to the production of ketones from fat metabolism, contributing to acidosis.

Decreased bicarbonate levels indicate a disruption in the body's ability to buffer acid, and identifying the underlying cause is essential for proper treatment and correction of the imbalance.

The HCO3- - Arterial marker on Labcorp's Arterial Blood Gas (ABG) Panel measures the concentration of bicarbonate ions (HCO3-) in the arterial blood. Bicarbonate plays a crucial role in maintaining the acid-base balance of the body, functioning as a buffer to regulate the pH of blood. It helps neutralize excess acids or bases, thus stabilizing the body’s pH levels. HCO3- is closely linked with the respiratory system's ability to excrete CO2 and the kidneys' ability to excrete or retain bicarbonate, making it a key indicator of both metabolic and respiratory health.