CHLORIDE PHYSIOLOGY

Chloride is the predominant anion in the ECF volume. Hyperchloremic, metabolic acidosis results from excess intake or inadequate excretion due to renal dysfunction. When administering infusions to such patients, bicarbonate, acetate, citrate, or phosphate salts should be substituted for chloride salts.

Excess loss of chloride in gastric secretions or urine causes hypochloremic alkalosis. Chloride depletion tends to limit bicarbonate excretion, and this may be caused by reduced delivery of chloride to the collecting tubules, where chloride is needed for bicarbonate secretion by means of bicarbonate-chloride exchange. Sodium reabsorption is enhanced in chloride-depleted states because it is generally associated with ECF volume depletion. When less chloride is available for reabsorption, a greater fraction of the sodium must be reabsorbed with bicarbonate through increased proton secretion.^[60] Sodium or potassium chloride should be administered if intravascular volume depletion or hypokalemia is present. If these are not a problem, 0.1 N hydrochloric acid (HCl) should be administered through a central catheter.

Chloride dose = (Cl_desired − Cl_measured ) × 0.2 × Weight (kg)