Sodium hydrogen carbonate is a sodium salt and belongs to the hydrogen carbonates. Colloquially, the substance is also known as sodium bicarbonate.
What is sodium hydrogen carbonate?
Sodium hydrogen carbonate is a sodium salt and belongs to the hydrogen carbonates. Colloquially, the substance is also known as sodium bicarbonate. Sodium hydrogen carbonate has the molecular formula NaHCO3. The substance is a sodium salt of carbonic acid and belongs to the group of hydrogen carbonates. Hydrogen carbonates, formerly also known as bicarbonates, are salts of carbonic acid that are formed by neutralizing the acid with a base. Hydrogen carbonates have a solid state of aggregation. Ionic bonds are present between the hydrogen carbonate ions and the cations, which provide a solid bond. Normally, sodium hydrogen carbonate is colorless, but in powder form it appears white. The substance is odorless and can be dissolved in water. Sodium hydrogen carbonate decomposes at a temperature above 50 °Celsius. Among other things, water and carbon dioxide are formed. In the United States, sodium hydrogen carbonate occurs as the natural mineral nahcolite. It is found finely dispersed in oil shale and can thus be obtained as a byproduct in the extraction of oil. However, sodium hydrogen carbonate can also be produced synthetically. For this purpose, purified sodium carbonate solution is reacted with carbon dioxide. Sodium hydrogen carbonate is then obtained by filtration. This must be dried very carefully so that it does not dissolve again. Sodium hydrogen carbonate is also produced in the Solvay process (also known as the ammonia-soda process). However, the sodium hydrogen carbonate produced in this process is contaminated by ammonium chloride and is therefore not usually used.
Pharmacological effect
Sodium bicarbonate used to be widely used to treat diseases with increased acidity in the stomach. Sodium bicarbonate causes an increase in intragastric pH. Within a short time, the pH in the stomach rises above 7. This is because sodium bicarbonate can bind stomach acid. However, sodium bicarbonate binds acids not only in the stomach but throughout the body.
Medical application and use
Because of its acid-binding properties, sodium hydrogen carbonate is used for various diseases. In the past, sodium bicarbonate was commonly used to treat heartburn as an antacid. Although the treatment is now considered outdated, many products for heartburn and stomach problems still contain sodium bicarbonate. For example, the well-known Bullrich salt consists of 100 percent sodium hydrogen carbonate. Sodium hydrogen carbonate performs a buffering function not only in the stomach, but also in the blood. For example, it is used as a buffer substance to compensate for the lack of bases in hemodialysis. In hemodialysis, fluid and dissolved molecules are removed from the circulating blood via filter systems outside the body. A dialyzer is used for this purpose. Dialysis is mainly performed in cases of kidney disease. However, hyperacidity, known as metabolic acidosis, can develop during this process. Sodium hydrogen carbonate is used to correct acidosis. In bicarbonate dialysis, the substance is added to the dialysate. The advantage over other agents for acidosis, such as acetate or lactate, is that sodium bicarbonate does not have to be metabolized before it can exert its full effect. This is why sodium bicarbonate is one of the buffer substances most commonly used in hemodialysis worldwide. When hemodialysis is accompanied by sodium bicarbonate, blood pressure drop, cramps, nausea and vomiting occur much less frequently. However, sodium bicarbonate is not only used in hemodialysis, but generally in the treatment of metabolic acidosis. Metabolic acidosis is a term for metabolic acidification of the blood and body. Causes include increased proton attack, decreased excretion of protons, or loss of bicarbonates. Thus, metabolic acidosis can occur in diabetic metabolic derailment, poisoning with acidic substances, severe diarrhea, or chronic renal insufficiency. Furthermore, sodium hydrogen carbonate is used in hyperkalemia. In hyperkalemia, there is too much potassium in the blood.The life-threatening electrolyte disturbance can be triggered by kidney diseases, various drugs or severe injuries to the muscles. Typical symptoms include paresthesias, muscle twitching, and cardiac arrhythmias. However, cardiovascular arrest is often the first, only, and usually fatal symptom. In the USA, many toothpastes contain sodium hydrogen carbonate. There, the substance is falsely attributed an abrasive effect. Abrasive substances are abrasives. In dental care, these substances are supposed to remove plaque from teeth, making them whiter.
Risks and side effects
When sodium bicarbonate is used to treat heartburn, it can make symptoms worse. The rapid increase in pH in the stomach leads to an increased release of the hormone gastrin. Gastrin is the strongest stimulus for stomach acid production. Thus, after ingestion of sodium bicarbonate, there is a reactively increased production of gastric acid, so that after some time there is even more acidification of the stomach. In addition, CO2 develops in the stomach when sodium hydrogen carbonate is ingested. Many patients find this very unpleasant. Belching and flatulence are the consequences. In the case of an overdose of sodium hydrogen carbonate, alkalosis can also develop. In this case, the pH of the blood rises due to an increase in bicarbonate to a value of over 7.45. The intracellular hydrogen ions are then exchanged for extracellular potassium, so that hypokalemia (a potassium deficiency) develops. Typical symptoms of a decreased blood potassium level include muscular adynamia with paralysis, reflex weakening or abolition, constipation, bladder paralysis, bowel obstruction, and cardiac arrhythmias. Rhabdomyolysis may also occur. In this case, the muscle fibers of the striated muscles break down. As a result, affected individuals suffer from muscle pain and weakness. In the worst case, the flooding of the muscle breakdown products into the kidney can cause acute renal failure.
