RESPIRATORY MEDICINE MADE SIMPLE : RESPIRATORY ACIDOSIS : INTRODUCTION , CLINICAL FEATURES AND CAUSES

 RESPIRATORY ACIDOSIS

Respiratory acidosis is a pathological state of the body in which there is excessive accumulation of Carbon dioxide in the blood due to inability of the lungs / failure of respiratory system to exhale the required carbon di oxide from the body necessary for maintaining a normal Acid Base balance.

pH is the parameter used to detect acid base balance in the body.

Normal Blood pH is between 7.35 – 7.45. Acidosis occurs when blood pH becomes lower than 7.35 and if it is due to respiratory pathology resulting in accumulation of Carbondioxide that combines with water to form Carbonic acid, this is called as Respiratory Acidosis

Respiratory acidosis is typically caused by an underlying disease or condition. This is also called respiratory failure or ventilatory failure.

Normally, the lungs take in oxygen and exhale CO2. Oxygen passes from the lungs into the blood. CO2 passes from the blood into the lungs. However, sometimes the lungs can’t remove enough CO2. This may be due to a decrease in respiratory rate or decrease in air movement due to an underlying condition such as:

Asthma

COPD

Pneumonia

Sleep apnea

Forms of respiratory acidosis

There are two forms of respiratory acidosis: acute and chronic.

Acute respiratory acidosis occurs quickly. It’s a medical emergency. Left untreated, symptoms will get progressively worse. It can become life-threatening.

Chronic respiratory acidosis develops over time. It doesn’t cause symptoms. Instead, the body adapts to the increased acidity. For example, the kidneys produce more bicarbonate to help maintain balance.

Chronic respiratory acidosis may not cause symptoms. Developing another illness may cause chronic respiratory acidosis to worsen and become acute respiratory acidosis.

Symptoms of respiratory acidosis

Initial signs of acute respiratory acidosis include:

Headache

Anxiety

Blurred vision

Restlessness

Confusion

Without treatment, other symptoms may occur. These include:

Sleepiness or fatigue

Lethargy

delirium or confusion

Shortness of breath

Coma

The chronic form of respiratory acidosis doesn’t typically cause any noticeable symptoms. Signs are subtle and nonspecific and may include:

Memory loss

Sleep disturbances

Personality changes

Common causes of respiratory acidosis

The lungs and the kidneys are the major organs that help regulate your blood’s pH. The lungs remove acid by exhaling CO2, and the kidneys excrete acids through the urine. The kidneys also regulate your blood’s concentration of bicarbonate (a base).

Some common causes of the acute form are:

Conditions that affect the rate of breathing

Muscle weakness that affects breathing or taking a deep breath

Obstructed airways (due to choking or other causes)

Sedative overdose

Cardiac arrest

Some common causes of the chronic form are:

Asthma

Chronic obstructive pulmonary disease (COPD)

Acute pulmonary edema

Severe obesity (which can interfere with expansion of the lungs)

Neuromuscular disorders (such as multiple sclerosis or muscular dystrophy)

Scoliosis