II. Physiology
- Background
- Chloride is an important negative ion (anion) in the maintenance of Fluid and Electrolyte Balance
- Chloride is also an important constituent of gastric fluid
- Chloride and Bicarbonate Balance
- Serum Chloride concentrations are inversely proportional to serum bicarbonate levels
- Serum Chloride increases when serum bicarbonate decreases
- Serum Chloride decreases when serum bicarbonate increases
- Chloride is the most common extracellular anion, and increases when bicarbonate anions are deficient
- Renal mechanisms maintain chloride when serum bicarbonate is low (acidosis)
- Serum Chloride concentrations are inversely proportional to serum bicarbonate levels
- Chloride also follows Sodium concentrations
- Chloride typically increases and decreases in line with Sodium concentration
- Chloride and Red Blood Cell (and Hemoglobin) Relationship
- Peripheral tissue CO2 enters Red Blood Cell (RBC)
- In the RBC, CO2 combines with H2O to form Hydrogen Ion and bicarbonate (via carbonic anhydrase)
- Bicarbonate leaves the RBC
- Chloride enters the cell (and Hydrogen Ion binds Hemoglobin)
- Lung tissue O2 enters Red Blood Cell
- Inspired Oxygen combines with Hemoglobin displacing Hydrogen Ion
- Hydrogen Ion combines with bicarbonate, forming H2O as well as CO2 which is expired
- Chloride leaves the Red Blood Cell
- Peripheral tissue CO2 enters Red Blood Cell (RBC)
- Chloride and Acid-Base
- Hypochloremic Acidosis
- Renal absorption of Sodium and bicarbonate increases when pH decreases (acidosis)
- When bicarbonate absorption increases, chloride absorption decreases (ion balance)
- Most often, acidosis is accompanied with Hypochloremia (except in cases as below)
- Hyperchloremic Acidosis
- Renal tubules may be unable to secrete Hydrogen Ion
- Without Hydrogen Ion, bicarbonate remains in the renal tubule as an anion that cannot be absorbed
- Chloride is absorbed instead when bicarbonate cannot be absorbed
- Hypochloremic Acidosis
III. Interpretation: Abnormal
-
Hyperchloremia
- Increased Serum Chloride
-
Hypochloremia
- Decreased Serum Chloride
IV. References
- Goldberg (2014) Clinical Physiology, p. 26-7
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Related Studies
| Concepts | Laboratory Procedure (T059) |
| SnomedCT | 166694004 |
| English | serum Cl-, SERUM CHLORIDE ION TESTS, Serum chloride, serum cl, chloride serum, serum chloride, Chloride - serum, Serum Chloride Ion Test |
| Dutch | serum chloride |
| French | Chlorure sérique |
| German | Chlorid im Serum |
| Italian | Cloruro sierico |
| Portuguese | Cloreto sérico |
| Spanish | Cloruro en suero |
| Japanese | 血清クロール, ｹｯｾｲｸﾛｰﾙ |
| Czech | Chloridy v séru |
| Hungarian | Szérum klorid |
