Anion Gap Blood
(AG)

Panel includes:

Bicarbonate (HCO3) Chloride (Cl) Potassium (K) Sodium (Na)

Sample type:

Blood sample (Plasma or Serum), Plasma is preferred specimen type.

Uses:

The anion gap blood test shows whether your electrolytes are out of balance or if your blood is too acidic or not acidic enough.Both conditions can be serious.

Precautions:

Avoid Hemolysis.
Use sample free of gross lipemia.
Prolonged exposure to air will falsely decrease bicarbonate results.
After collection, gently invert tube 8-10 times.
Specimen should be processed within 2 hours – See Processing Instruction.
Plasma: Centrifuge after collection.
Serum: Allow blood to clot for 30 minutes in a vertical. position and centrifuge within 2 hours.
Minimum plasma/serum: 0.5 Ml.

Interference:

The anion gap falls by approximately 2.5 mEq/L for every 1 g/dL reduction in serum albumin concentration.
Hyperlipidemia may cause under measurement of Na+ (sodium) and falsely decrease AG..
Drugs that increase the AG include: carbenicillin, carbonic anhydrase inhibitors (e.g., acetazolamide), diuretics, ethanol, methanol, penicillin, and salicylate.
Drugs that decrease AG may include acetazolamide, lithium, polymyxin B, spironolactone, and sulindac.
Changes to fluid intake or fluid loss from the body.
Disorders affecting the kidneys, liver, lungs, adrenal glands, or heart.
Malnutrition, gastrointestinal problems, or changes to how nutrients are absorbed.
Use of certain medications, including those that can affect fluid levels or acid-base balance.
Prolonged exposure to air will falsely decrease bicarbonate results.

Pre-analytical errors:

let the specimen into the air without stopper,Hemolysis or Lipemia or Icterus sample.

The corrective action:

The sample must be rejected and another sample be obtained.

Post analytical errors:

write the wrong name in the report or the wrong results.

The corrective action:

If the report is not delivered to the patient and this error is discovered, the correct result or the correct name must be written, but if the report is delivered to the patient, you must communicate with him, apologise to him, and tell him that an error has occurred and replace it with the correct report.

Reference Range:

SODIUM

0 up to 3 Years: 132-144 mmol/L

3 Years up to 18 Years: 134-146 mmol/L

18 Years and up: 134-146 mmol/L

POTASSIUM

0 up to 3 Days: 4.5-6.5 mmol/L

3 Days up to 90 Days: 3.8-5.5 mmol/L

90 Days and up: 3.4-5.0 mmol/L

CHLORIDE

98-112 mmol/L

HCO3

0 up to 3 Years: 20-26 mmol/L

3 Years and up: 21-29 mmol/L

ANION GAP

9-18 mmol/L