- See also: Metabolic acidosis
In medicine, acidosis is an acid-based imbalance that is a "pathologic condition resulting from accumulation of acid or depletion of the alkaline reserve (bicarbonate) content of the blood and body tissues, and characterized by an increase in hydrogen ion concentration (decrease in pH). (Dorland, 27th ed)."
In evaluating acidosis, there can be a number of calculations for which computer assistance is helpful. Listed below are several Web-based calculators. Specialists make extensive use of programmable calculators and personal digital assistant applications.
- Winter's formula (Expected pCO2 = 1.5 * HCO3 + 8 ± 2)
- Multiple anion gap calculations
- Anion Gap (without K): Na - (Cl + HCO3)
- Anion Gap (with K): (Na + K) - (Cl + HCO3)
- Delta Gap (without K): [Na - (Cl + HCO3)] - 12
In acute respiratory acidosis, for each increase in the PaCO2 of 10 mmHg, the pH decreases by 0.08.
"Metabolic acidoses are classified in terms of the anion gap."
High anion gap
Examples include: Diabetic ketoacidosis
Low anion gap
"A decrease in the normal AG occurs in dilutional states, hypoalbuminemia, hypercalcemia, hypermagnesemia, hypernatremia, diseases associated with hyperviscosity, bromide intoxication, and in certain paraproteinemias."
Also, surgery that created urinary diversion into the intestines (such as an ileal conduit) can cause hyperchloremic metabolic acidosis due to reabsorption of sodium. This acidosis may be worse during worsening of renal failure.
For each increase in the anion gap over 12 the bicarbonate should fall by the same amount. Thus Δ/Δ (Δ anion gap /Δ HCO3):
- Δ/Δ < 1 suggests "that a mixed high AG and hyperchloraemic acidosis is present"
- Δ/Δ > 1 suggests "mixed metabolic alkalosis and metabolic acidosis is likely to be present"
- Anonymous (2021), Acidosis (English). Medical Subject Headings. U.S. National Library of Medicine.
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