Chloride (Blood Chloride, Cl¯ )
- This is done on the serum or plasma of the patient.
- Except emergency collect fasting sample because there is a slight decrease after the meal.
- Chloride estimated in sweat to rule out cystic fibrosis.
- Other samples are CSF and 24 hours of Urine.
Purpose of the test (Indications)
- As a part of electrolytes, acid-base balance.
- It gives status fo hydration.
- For the diagnosis of cystic fibrosis.
- Separate serum or plasma from the cells, as a change in pH, will alter the distribution of chloride.
- Avoid hemolysis.
- Serum, plasma, and urine are stable for one week at 1 to 4 °C or room temperature.
- A frozen sample can be kept for one year.
- Drugs that may increase the chloride level are ammonium chloride, acetazolamide, cortisones, androgens, and estrogens.
- Drugs that may decrease the chloride level are aldosterone, corticosteroids, thiazide diuretics, and loop diuretics.
- Chloride is the major negative electrolyte(anion) in the extracellular fluid.
- Chloride with sodium represents the majority of the osmotically active constituents of plasma.
- The plasma interstitial fluid of chloride anion is 103 mmol/L.
- Its concentration in intracellular fluid (RBC) is 45 to 54 mmol/L.
- While in the intracellular fluid of other tissue is only 1 mmol/L.
Extracellular fluid ECF meq/L Intracellular fluid ICF meq/L Sodium 142 10 Potassium 5 156 Chloride 104 4 Bicarbonate 24 12
- Chloride ions in the food are absorbed completely in the intestine.
- They are filtered from the plasma at the glomerular level and passively reabsorbed, along with Na+ in the proximal tubules.
- Chloride interacts with sodium to maintain the osmotic pressure of blood.
- Its main purpose is to maintain the electrical neutrality as salt with sodium.
- Aldosterone increases the reabsorption of sodium than chloride maintains the neutrality.
- Chloride acts as a buffer to help in acid-base balance.
- The concentration of the Cl– changes inversely with the changes in concentration of HCO3–.
- Chloride filtered at glomerulus passively and reabsorbed at proximal tubules. Further absorption at the loop of Henle.
- There is a chloride pump in the ascending limb of the loop of Henle.
- Sodium is absorbed passively while Chloride is absorbed actively by the pump.
- Excess of the chloride is excreted in the urine and sweat.
- Functions :
- Maintenance of water balance and osmotic pressure with the help of sodium.
- Chloride moves into cells in exchange for bicarbonate produced in the cells.
- It can maintain electrical neutrality.
- It helps as a buffer to help in the acid-base balance.
- Anion-cation balance in the extracellular fluid compartment.
- chloride provides electroneutrality, particularly in relation to Na+.
Sign and symptoms of Hypochloremia
- There is the loss of Cl–, usually, the result of hyponatremia or elevated HCO3– concentration, as in metabolic alkalosis.
- This will develop with vomiting and loss of HCL.
- Cystic fibrosis is characterized by hypochloremia.
- Restricted use of salt or in use of diuretics is accompanied by Cl– deficiency.
- There is hyperstimulation of the nervous system and muscles.
- Shallow breathing.
Sign and symptoms of Hyperchloremia
- This will take place when there is too much sodium or too little bicarbonate.
- More than a normal amount of Cl/ can be expected with hypernatremia or metabolic acidosis.
- Ingestion of excessive Cl- accompanies the use of an ammonium chloride diuretic.
- Usually, no specific symptoms are associated with chloride excess.
- There are lethargy and weakness.
- Deep breathing.
- Serum = 95 to 105 meq / L (98 to 106 mmol/L)
- Urine = 110 to 250 meq/ 24 hours
- normal = 5 to 40 meq/L
- marginal value = 30 to 70 meq/L
- cystic fibrosis = 60 to 200 meq/L
- CSF :
- Infant = 110 to 130 meq/L
- Adult = 118 to 132 meq/L
- These are 15% higher than those in serum.
- Saliva without stimulation = 5 to 20 meq/L
|Serum or plasma|
|Cord blood||96 to 104|
|Premature infant||95 to 110|
|0 to 30 days||98 to 113|
|Adult||98 to 107|
|>90 years||98 to 111|
|Urine 24 hours||meq/24 hours|
|Infants||2 to 10|
|<6 years||15 to 40|
|Male 6 to 10 years||36 to 110|
|Female 6 to 10 years||18 to 74|
|Male 10 to 14 years||64 to 176|
|Female 10 to 14 years||36 to 173|
|Adult||110 to 250|
|>60 years||95 to 195|
|Infant||110 to 130|
|Adult||118 to 132|
|Feces 24 hours||meq/L|
|3.2 to ± 0.7|
|Normal||5 to 35|
|Marginal||30 to 70|
|Cystic fibrosis||60 to 200|
|normal without stimulation||5 to 20|
- urinary tract obstruction, glomerulonephritis, renal tubular acidosis, and acute renal failure.
- Diabetes Insipidus.
- Salicylate intoxication.
- Prolonged diarrhea with the loss of sodium bicarbonate.
- Respiratory alkalosis.
- Some cases of primary hyperparathyroidism.
- Maybe because of excessive intake.
- Cushing syndrome.
- Renal tubular acidosis.
- Due to the excessive infusion of normal saline.
Decreased level (Hypochloremia):
- excessive sweating.
- Prolonged vomiting.
- Gastric suction.
- Salt losing nephritis.
- Addisonian crises.
- Metabolic acidosis, associated with increased organic anions.
- Respiratory acidosis.
- Water intoxication.
- Diuretic therapy.
Critical values in serum or plasma are:
- >115 meq/L or <80 meq/L.