Respiratory acidosis

Acid - base balance is important in our body and is done primarily by three mechanisms.

1. Buffering mechanism

2. Respiratory mechanism

3. Renal mechanism

The main buffers in our body is the bicarbonate ion and CO2.

The CO2 combines with H2O and forms carbonic acid (H2CO3).

This carbonic acid is split into H+ and HCO3-

In acidemia,

there is an increase in concentration of carbonic acid in plasma. This is due to decrease in alveolar ventilation leading to retention of CO2.

The reason for decrease alveolar retention is:

1. Obstruction to respiration: this may be due to pulmonary diseases like pneumonia, emphysema etc.

2. Depression of respiration: maybe due to depressant drugs like morphine.

3. Cardiac arrest: due to hypoxia.

This results in respiratory acidosis.

(Actually, acidosis or alkalosis are pathological states used to describe the conditions of acidemia and alkalemia.)

Now, the body tries to compensate this condition by:

1. Increasing renal absorption of bicarbonate ions.

2. Elevation of acidic output in urine.

3. Stimulation of respiratory centers (except in the case of depressant).