Maintenance of acid base balance in the body fluids is vital for normal functioning of tissues. Measure of acidity or alkalinity of fluids is expressed numerically as pH. In normal health, pH of arterial blood and other body fluid remains between 7.37 and 7.42. Blood pH below 6.8 and above 7.8 is detrimental to health.
Acidosis occurs when there is rise of acid level in the body fluids or there is a disturbance to remove alkali from the body fluids. The body regulates acid alkaline balance with the help of renal, respiratory and metabolic mechanism. Acidosis can be of two types, respiratory acidosis and metabolic acidosis.
Respiratory acidosis occurs when there is elevation of carbon dioxide in the body fluids and compensatory rise of bicarbonate. In lungs the diffusion of carbon dioxide from the blood vessels into the tiny alveoli (primary compartment of lungs where exchange of gases occurs) is so rapid that a rise of carbon dioxide in plasma (body fluid) can occur only if there is inadequate ventilation.
Causes Of Metabolic And Respiratory Acidosis
Some of the causes for respiratory acidosis are:
- Depression of respiratory center as a result of narcotic overdose, anesthesia, head injury, damage of blood vessels or infection.
- Weakness of chest muscles caused due to conditions like myasthenia gravis, transverse myelitis, muscle relaxant drugs or severe decrease in body potassium.
- Obstruction in wind pipe as a result of foreign body or as a result of severe bronchospasm.
- Chest injury.
- Chronic lung diseases such as chronic bronchitis, emphysema, spinal deformities such as kyphoscoliosis,
- Acute lower respiratory tract infections.
Metabolic acidosis occurs when acid level elevates in the body fluid or the kidney is not able to remove acid from the body. The types of metabolic acidosis include:
- Diabetic ketoacidosis. There is presence of ketone bodies as a result of uncontrolled diabetes.
- Hyperchloremic acidosis occurs when there is loss of sodium as in cases of diarrhea, or due to diuretics.
- Lactic acidosis occur when there is built up of lactic acid in the body. It occurs due to overproduction, hepatic failure, impaired kidney capacity to excrete acids etc. Alcohol intoxication, medications, low blood sugar, salicylate poisoning etc.
Symptoms Of Acidosis
Deep and rapid breathing is characteristic of metabolic acidosis. Patient may become confused, drowsy, and ultimately slip into coma. This usually occurs in severe case of keto acidosis or lactic acidosis. Cardiac function can be impaired. In chronic metabolic acidosis osteoporosis, osteomalacia which may cause bone pains. Fatigue from slightest work, headache, nausea, abdominal discomfort, diarrhea, and low blood pressure are some of the symptoms. Rise of potassium level in blood is common in spite of loss of potassium.
Respiratory acidosis symptoms:
The symptoms mainly depend on the severity and its rapid onset. When respiratory acidosis is acute and severe the patient feels sleepy which may later on progress to coma.
Tremor is common in such patient. Headache due to raised intracranial pressure is also common. The patient has difficulty in breathing and rapid respirations are another sign of respiratory acidosis.
Treatment For Acidosis
The treatment of acidosis varies and depends on the cause, its acuteness, and the severity. Many acute conditions are often associated with fluid loss and electrolytes. Replacement of electrolyte and fluid is necessary in such conditions.
In metabolic acidosis underlying condition should be carefully handled. If the cause is diabetic ketoacidosis, the primary treatment is insulin and replacement of fluids through intravenous route. Alcoholic ketoacidosis can be controlled with intravenous dextrose and normal saline. In case of lactic acidosis, prompt administration of sodium bicarbonate may be considered by the doctor.
In case of respiratory acidosis, oxygen may help the patient. There may be a need for mechanical ventilation. In some cases sodium bicarbonate may be given.