Sodium bicarbonate

Overview of sodium bicarbonate in medical use

Sodium Bicarbonate

File:Sodium-bicarbonate-3D-vdW.png

3D model of a sodium bicarbonate molecule

Sodium bicarbonate, commonly known as baking soda, is a chemical compound with the formula NaHCO_. It is a salt composed of a sodium cation (Na_) and a bicarbonate anion (HCO__). Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). It is a component of the mineral natron and is found dissolved in many mineral springs.

Medical Uses

Sodium bicarbonate is used in a variety of medical applications. It is primarily used to treat conditions caused by high acidity in the body, such as metabolic acidosis, which can occur in severe renal disease, uncontrolled diabetes, and circulatory insufficiency due to shock or severe dehydration.

Metabolic Acidosis

In cases of metabolic acidosis, sodium bicarbonate is administered to increase the pH of the blood. This is crucial in conditions where the body produces excessive acid or when the kidneys are not removing enough acid from the body. Sodium bicarbonate acts as a buffer, neutralizing excess acid in the blood.

Cardiac Arrest

During cardiac arrest, sodium bicarbonate may be used as part of advanced cardiac life support (ACLS) to correct acidosis and improve the effectiveness of other medications. However, its use is controversial and should be guided by arterial blood gas analysis.

Hyperkalemia

Sodium bicarbonate is also used in the treatment of hyperkalemia, a condition characterized by elevated levels of potassium in the blood. It helps to shift potassium into cells, thereby lowering the potassium concentration in the blood.

Urinary Alkalinization

Sodium bicarbonate can be used to alkalinize the urine in cases of urinary tract infections or to enhance the excretion of certain drugs and toxins. By increasing the pH of urine, it can help prevent the crystallization of certain compounds, reducing the risk of kidney stones.

Mechanism of Action

Sodium bicarbonate acts as a buffer by dissociating into sodium and bicarbonate ions in solution. The bicarbonate ion can neutralize hydrogen ions, forming carbonic acid, which then decomposes into water and carbon dioxide. This reaction helps to maintain the pH balance in the body.

Side Effects

While sodium bicarbonate is generally safe when used appropriately, it can cause side effects, especially when used in large amounts or for prolonged periods. Common side effects include:

• Metabolic alkalosis
• Hypernatremia (elevated sodium levels)
• Hypokalemia (low potassium levels)
• Edema due to sodium retention

Administration

Sodium bicarbonate can be administered orally or intravenously, depending on the clinical situation. Oral administration is typically used for mild acidosis or urinary alkalinization, while intravenous administration is reserved for more severe cases.

Related Pages

• Acid-base homeostasis
• Renal physiology
• Electrolyte imbalance
• Buffer solution