User:Je.rrt/Acid-base disorders

Each day approximately 15,000 mmol of carbon dioxide (CO2, which can generate carbonic acid as it combines with water) and 50 to 100 meq of nonvolatile acid (mostly sulfuric acid derived from the metabolism of sulfur-containing amino acids) are produced. Acid-base balance is maintained by normal pulmonary and renal excretion of carbon dioxide and acid, respectively.

Renal excretion of acid is achieved by combining hydrogen ions with either urinary titratable acids, mainly phosphate (HPO42- + H+ → H2PO4-), or with ammonia to form ammonium (NH3 + H+ → NH4+). When increased quantities of acid must be excreted by the kidney, the major adaptive response consists of increases in ammonia production (derived from the metabolism of glutamine) and ammonium excretion into the urine.

Acid-base status is usually assessed by measuring the components of the bicarbonate-carbon dioxide buffer system in blood:

Dissolved CO2 + H2O ↔ H2CO3 ↔ HCO3- + H+

Most commonly, the partial pressure of CO2 (PCO2) and the pH are each measured using specific electrodes. The serum HCO3- concentration is then calculated from the Henderson-Hasselbalch equation