METABOLIC ACIDOSIS : DEFINITION , CAUSES, MECHANISM AND SYMPTOMS :

METABOLIC ACIDOSIS : DEFINITION , CAUSES, MECHANISM AND SYMPTOMS :

 

METABOLIC ACIDOSIS

 

Metabolic acidosis is a sinister acid base disorder in which there is accumulation of excessive acid in the blood and body tissues.It is a serious and life threatening condition

 

PATHOPHYSIOLOGY OF METABOLIC ACIDOSIS

 

OCCURS DUE TO THREE MAIN MECHANISMS:

 

1. EXCESSIVE PRODUCTION OF ACID IN THE BODY

 

2. LOSS OF ACID BUFFERING SYSTEM WHICH IS LACK OF BICARBONATE IN THE BODY

 

3 . INABILITY OF KIDNEYS TO GET RID OF EXCESSIVE ACID FROM THE BODY

 

PATHOPHYSIOLOGY

 

Metabolic acidosis can lead to acidemia, which is defined as arterial blood pH that is lower than 7.35

 

Acute metabolic acidosis, lasting from minutes to several days, often occurs during serious illnesses or hospitalizations, and is generally caused when the body produces an excess amount of organic acids (ketoacids or lactic acid).

 

Chronic metabolic acidosis, lasting several weeks to years, can be the result of impaired kidney function (Chronic Kidney Disease) and/or bicarbonate wasting.

 

CAUSES OF METABOLIC ACIDOSIS

 

There are several types of metabolic acidosis:

 

Diabetic acidosis (also called diabetic ketoacidosis and DKA) develops when substances called ketone bodies (which are acidic) build up during uncontrolled diabetes.

 

Hyperchloremic acidosis is caused by the loss of too much sodium bicarbonate from the body, which can happen with severe diarrhea.

 

Kidney disease (uremia, distal renal tubular acidosis or proximal renal tubular acidosis).

 

Lactic acidosis.

 

Poisoning by aspirin, ethylene glycol (found in antifreeze), or methanol.

 

Severe dehydration.

 

 

 

MECHANISM OF METABOLIC ACIDOSIS

 

Metabolic acidosis is characterized by a low concentration of bicarbonate (HCO−3), which can happen with increased generation of acids (such as ketoacids or lactic acid), excess loss of HCO-3 by the kidneys or gastrointestinal tract, or an inability to generate sufficient HCO−3.

 

The body regulates the acidity of the blood by four buffering mechanisms.

 

Bicarbonate buffering system.

 

Intracellular buffering by absorption of hydrogen atoms by various molecules, including proteins, phosphates and carbonate in bone.

 

Respiratory compensation. Hyperventilation will cause more carbon dioxide to be removed from the body and thereby decrease pH.

 

Kidney compensation

 

SYMPTOMS OF METABOLIC ACIDOSIS

 

Symptoms

 

Most symptoms are caused by the underlying disease or condition that is causing the metabolic acidosis.

 

Metabolic acidosis itself most often causes rapid breathing.

 

Acting confused or very tired may also occur.

 

Severe metabolic acidosis can lead to shock or death.

 

In some situations, metabolic acidosis can be a mild, ongoing (chronic) condition.