Difference Between Metabolic and Respiratory Acidosis

Acidosis roughly means something with acidity. Both metabolic and respiratory acidosis are related with changes in acidity of the blood of animals, especially humans. For mammals, there is a tolerable range of pH levels in the blood, which is usually between 7.35 and 7.5 for a healthy individual. However, no individual could tolerate any pH level in blood outside the range of 6.8 – 7.8. Therefore, acidosis is a very important phenomenon to be concerned of, and it can cause irreversible damage to cells. This article will discuss the exact facts regarding both metabolic and respiratory acidosis with the all-important differences between the two.

Metabolic Acidosis

Metabolic acidosis is generally the increase of acidity or decrease of the pH level of blood and/or any other related body tissue. Metabolic acidosis can mainly take place when acids are produced through metabolism. However, the condition can also occur when the kidneys do not excrete unnecessary acids, or when the rate of excretion process is slowed down. Additionally, the production of acids via other means such as lactic acid formation could also be resulted in metabolic acidosis. Lactic acid formation takes place when there is not enough oxygen being delivered to tissues (especially to muscle fibres), and the exec lactate condition causes lactic acid formation in the tissue that cramp the muscle eventually. However, the condition is usually corrected with proper delivery or diffusion of oxygen to the muscles.

The general metabolic acidosis is usually rectified through the lungs by increasing the exhalation process, which is a method of hyperventilation stimulated through chemoreceptors known as Kussmaul breathing. However, when the metabolic acidosis is not compensated by the body, proper treatment to the condition should be taken by correcting the real cause of the acid accumulation in the tissues or in the blood. The metabolic acidosis can occur when the blood pH level is dropped from 7.35, but that value for a developing foetus is 7.2 (Foetal metabolic acidemia). When the pH level is dropped below 6.8, it is very difficult to rectify the problem.

Respiratory Acidosis

When the respiratory system suffers with increased level of acidity or decrease of pH level of pulmonary blood, respiratory acidosis is taking place. Usually, this condition takes place when carbon-dioxide concentration becomes high in the blood, which is known as the hypercapnia. Hypoventilation or reduced ventilation of the blood would be the closest reason for hypercapnia condition to occur. It would be important to know that respiratory acidosis is not mainly caused through respiratory problems, but anaesthetic and sedative drugs or problems associated with brain such as tumours or head injuries could cause the increases of carbon-dioxide in blood. Additionally, asthma, pneumonia, bronchitis, and many other conditions could also be causing respiratory acidosis in humans. Some of those causing the condition may have resulted from remedial effects of metabolic alkalosis, as well.

The bicarbonate concentration can either increase or stay normal during respiratory acidosis conditions. An increased bicarbonate concentration will automatically try to compensate the problem, but sometimes there may be irreversible damages from chronic respiratory acidosis conditions. It would also be important to state that the foetal respiratory acidemia takes place when the placental pH value drops below 7.2.

Metabolic Acidosis vs Respiratory Acidosis

• Both conditions are increases of acidity of blood, but the places and processes are different as the names indicate.

• Metabolic acidosis has more causes than respiratory acidosis.

• Metabolic acidosis is more severe than respiratory acidosis.

• Bicarbonate concentration can be either normal or increased in respiratory acidosis, whereas metabolic acidosis features a low level of bicarbonates.

• Hyperactivity can cause metabolic acidosis while respiratory acidosis can take place due to reduced inactiveness.