Reference Ranges

Question 1

Sodium

Clinical Significance

Answer 1

133-146 mmol/L

ISE: glass or PVC with crown ether

<125 / >155

High: Conn’s, Hyperadrenalism, 2° aldosteronism, Dehydration, Diabetes Insipidous
Low:
N Osm - Electolyte Exclusion
H Osm - hyperglycemic, uremia, mannitol
L Osm - Liver, Kidney, Heart diease. Addisons. SIADH

Question 2

Bicarbonate (HCO3)

Answer 2

23-31 mmol/L

pH: glass membrane

ISE: gas permeable (teflon, silicon)
Exposure to air: decrease [CO2]

High: Metabolic ALKALOSIS
Low: Metabolic ACIDOSIS

Question 3

Anion Gap

Answer 3

Na - (Cl + HCO3)
4-16 mmol/L

Unmeasured Ions (proteins, sulphates, phosphates)

Inc: Diabetic ketoacidosis, lactic acidosis, renal failure, intoxication
Dec: Hypoalbuminemia, hypercalcemia, hypermagnesemia

Question 4

Lactate Dehydrogenase

Answer 4

100-225 U/L

found: throughout body (liver, heart, sk muscle, RBC, PLT)
CoEnz: NAD+

Non-specific indicator of Anemia, Liver or Heart Disease

Question 5

Alkaline Phosphatase (ALP)

Answer 5

30-130 U/L

Liver, intestine, bone, placenta, RBC
*Osteoblasts, Hepatocytes

Activator: Zn, Mg
Inhib: PO4, Anticoag

Question 6

Calcium

Answer 6

2.10-2.60

<1.65 / >3.25
ISE: calcium ionphore on solid support

High: Parathyroid adenoma, Malignancy, Tumours invading bone, Renal failure, Acromegaly, hyper/hypo thyroidism
Low: Hypoalbuminemia, Liver and heart disease, Chronic renal failure, Proteinuria, Hyperphosphatemia, Hypoparathyroidism, Neck surgery

Question 7

Potassium

Answer 7

3.5-5.0
<2.6 / >6.2

ISE: PVC & Valinomycin

*Hemolysis, thrombocytosis, leukocytosis

High: Acidosis, IVH, rhabdomyolysis, burns, tissue hypoxia, addisons, hypoaldosteronism, treatment of ACE inhibitors
Low: Insulin therapy, renal tubular acidosis and necrosis, corticoid hormone excess, met acidosis

Question 8

Chloride

Answer 8

96-109 mmol/L

ISE: polymer with quaternary ammonium salt

High: Conn’s, Hyperadrenalism, 2° aldosteronism, Dehydration, Diabetes Insipidous
Low:
N Osm - Electolyte Exclusion
H Osm - hyperglycemic, uremia, mannitol
L Osm - Liver, Kidney, Heart diease. Addisons. SIADH

Question 9

Magnesium

Answer 9

0.70-1.00 mmol/L
<0.40 / >1.90

*Hemolysis, Icterus, Lipemia

High: Hospital patients, Excess administration of antacids, enemas and fluids
Low: Hospital patients, diarrehea, vomiting, bowel surgery, diabetes mellitus, diuretics, antibiotics, alcoholism

Question 10

Blood pH

Answer 10

<7.35 acidemia
>7.45 alkalemia

CO2 + H2O <-> H2CO3 <-> H + HCO3-

Question 11

Phosphorus

Answer 11

0.80 - 1.45 mmol/L
<0.40

*hemolysis, icterus, lipemia

High: Acromegaly, Hypoparathyroidism, pseudoparathyroidism
Low: Shift from ECF to ICF (resp. Alk, glucose administration, insulin), Renal wasting, Hyperparathyroidism, Fanconi’s syndrome, inherited rickets, osteomalacia