Pathology - Metabolic Acidosis

Pathology - Metabolic Acidosis 
Causes of anion-gap metabolic acidosis include renal failure, lactic acidosis, diabetic ketoacidosis, specific poisons such as methanol, paraldehyde, phenformin, cyanide, carbon monoxide, ethanol, ethylene glycol, salicylate, and INH.
Causes of normal anion-gap metabolic acidosis include traveler's diarrhea, acetazolamide overdose, glue sniffing, renal tubular acidosis, and hyperchloremic metabolic acidosis.

Pathology 
Primary Disturbance: Reduction in HCO3 levels.
Compensatory response: Reduction in Pco2 causes vasodilation and reduced cardiac contractility (insensitive to catecholamines), potentially resulting in shock.

Symptoms and signs 
Hyperventilation or Kussmaul breathing (deep, sighing respirations); other signs and symptoms vary based on the underlying etiology of metabolic acidosis.
Laboratory results: pH, pc02, and HCO3 levels have reduced.


Therapy 
Administer bicarbonate if pH is below 7.1, address the root cause, and closely observe fluid volume and electrolyte levels.
Calculation of anion gap: Anion gap is calculated by subtracting the sum of chloride and bicarbonate ions from the sodium ion concentration. The usual range for anion gap is 6-12 mEq/L, and it increases when an unmeasured anion replaces HC03-.
Compensation computation using Winter's formula: The decrease in PCO2 can be calculated using the formula: 1.5(HCO3-) + 8 ± 2.