Name common acid base disorders with their primary defect and cause and compensation.

1. Respiratory Acidosis:

a. Primary defect: Increase pCO₂

b. Cause:

·        Ventilatory failure

·        Chronic bronchitis and bronchial asthma

·        Emphysema

·        Depression of nervous system

·        Morphine poisoning

c. Compensation: Compensated by renal mechanism. Excess CO₂ is counteracting by renal HCO₃ retention and increased H⁺ secretion and excretion.

2. Respiratory alkalosis:

a. Primary defect: Decrease in pCO₂ as result of hyperventilation.

b. Causes:

·        Hyperventilation (voluntary, forced, hysterical)

·        CNS disease affecting the respiratory centers

·        Salicylate poisoning

·        Hepatic coma.

c. Compensation: Compensated by kidneys. Low pCO₂ in the arterial blood is compensated by increased HCO₃ excretion in urine.

3. Metabolic acidosis:

a. Primary defect: Decrease HCO₃

b. Causes

1)     Metabolic acidosis with normal anion gap

a)      Increased gastrointestinal bicarbonate loss

i)        Diarrhea

ii)      Fistulae

iii)    Uretero-sigmoidostomy

b)     Increased renal bicarbonate loss

i)        Renal tubular acidosis

ii)      Carbonic anhydrase inhibitors

iii)    Tubular damage

c)      Increased HCl production

i)        Ammonium chloride production

2)     Metabolic acidosis with an increased anion gap

i)        Diabetic ketoacidosis

ii)      Lactic acidosis

iii)    Exogenous acid

iv)    Renal failure

c. Compensatory mechanism: Primarily compensated by respiratory system. A low P^H stimulates respiratory centers, the patient hyperventilates and blow out CO₂.

4. Metabolic Alkalosis:

a. Primary defect: Increase in plasma HCO₃ Concentration.

b. Causes:

·        Loss of acid (Vomiting)

·        Diuretic therapy

·        Potassium deficiency

·        Extracellular volume depletion

·        Excess mineralocorticoids (Primary and secondary aldosteronism, Cushing’s syndrome)

·        Excess alkali administration

·        Post hypercapnic alkalosis

c. Compensation: Compensated by respiratory system by hypoventilation resulting in an increase in plasma pCO₂.