Laboratory Tests

What is Hemoglobin?

Oxygen-carrying pigment protein in a red blood cell

normal hemoglobin range

135-180g/L

What does a LOW HEMOGLOBIN value indicate?

• More concerning

• Could be caused from:

  • blood loss

  • inadequate nutrition (iron deficiency anemia or renal failure)

  • lack of erythropoietin that is stimulating the bone marrow (EPO stimulates bone marrow to produce RBC’s)

What does a HIGH HEMOGLOBIN value indicate?

• Living at higher elevation due to their increased need for oxygen,

• those living with COPD to due to their increased oxygen demand

• those doping with erythropoietin

• Rarely is a high hemoglobin linked to a pathological condition.

What is Hematocrit

The proportion of red blood cells in a whole blood sample

normal Hematocrit range

0.41-0.52 L/L

What does a LOW HEMATOCRIT level indicate?

often secondary to:

• overhydration

• nutritional deficiencies

• blood loss

• bone marrow suppression

• leukemia

• lead poisoning

• Hodgkin's lymphoma

• chemotherapy treatment

What does a HIGH HEMATOCRIT level indicate?

• dehydration

• hypoxia

• cigarette smoking

• polycythemia

• Vera tumors

• erythropoietin abuse

• lung diseases

• blood doping

• core pulmonal

What CBC values usually fluctuate similarly?

RBC’s, Hgb, and Hct

What are Platelets?

Measures number of platelets — colorless blood cells integral to clotting

What medication can interfere with platelet fromation/aggregation

aspirin

normal Platelets range

150 - 400 x 109/L

What does a LOW PLATELETS number indicate?

Thrombocytopenia

• caused by ineffective bone marrow production of platelets or accelerated destruction of platelets

• If bleeding is severe though generally speaking was something we often treat it with IVIG (intravenous immunoglobulin)

• patients are usually asymptomatic with low levels unless they have a platelet value that's less than 50,000

What does a HIGH PLATELETS number indicate?

• Can be primary i.e. as a standalone condition or secondary caused by another condition like anemia or cancer.

  • Sometimes patients who have high levels of platelets are more at risk for clotting complications such as stroke, DVT, P/E, or MI.

What is in the WBC Count + Differential

• WBC’s

• Neutrophils

• Lymphocytes

• Basophils

• Eosinophils

• Monocytes

What are White Blood Cells (WBC’s)?

• Exist in the blood, lymphatic system and tissues

• Are an important part of the body’s immune system

• Protect against infection and have a role in inflammation and allergic reactions

normal WBC’s range

4.0 - 11.0 x 109/L

What does a LOW WBC number indicate?

Leukopenia:

• cancer treatment

• antipsychotic medication use

• HIV

• hepatitis

• rheumatoid arthritis

What does a HIGH WBC number indicate?

Leukocytosis:

• infection

• post-op

• bone marrow disease

• reaction to medicine

• sudden stress

• smoking

Neutrophils

increase with bacterial infection

Lymphocytes

increase with viral infection

Eosinophils

increase with allergic reactions

Blast cells

Immature WBC’s

• Normally, we should not see immature white blood cells circulating in the bloodstream, but during severe or prolonged infections, the bone marrow may release them early as part of the body’s response

What is C-reactive protein (CRP)?

A protein made by the liver

normal CRP range

less than 10 mg/L

What does a HIGH CRP number indicate?

• Increased levels indicate non-specific inflammation

• Released within a few hours after injury, start of infection, or inflammation, so it is helpful for trending severity of inflammation and/ or response to treatment

  • can occur after trauma, after a heart attack, with active or untreated autoimmune disorders, and with serious bacterial infections such as in sepsis

normal Sodium (Na+) range?

135-145 mmol/L

What do you think can cause a LOW sodium in the blood?

• Changes can be associated with too little fluid (dehydration) or with too much fluid (edema) often resulting in swelling in the legs

• decrease in aldosterone (decrease sodium levels)

What can cause a HIGH level of sodium in the blood?

• Thirst

• CNS impairment

• confusion

• neuromuscular excitability

• hyperreflexia

• seizures

• coma

normal Chloride (Cl-) range

98 -108 mmol/L

What does a LOW CHLORIDE number indicate? 

• Emphysema

• chronic lung diseases

• vomiting 

What does a HIGH CHLORIDE number indicate?

• Dehydration

• kidney disease

• hyperventilation

normal potassium (K+) range

3.5 - 5.0mmol/L

How are Potassium levels mainly controlled?

Levels are mainly controlled by aldosterone, a hormone produced by the adrenal glands above the kidneys.

What can happen when there is an imbalance in Potassium levels?

Levels that are too low or too high can alter the function of the nerves and muscles and there can be serious health complications such as:

• shock

• breathing problems

• irregular heartbeats

• the heart muscle can even lose its ability to contract

What can impact Potassium levels?

• Low dietary intake

• blood loss

• nausea and vomiting

• diarrhea

• renal loss due to diuretics

What does a LOW POTASSIUM number indicate?

Hypokalemia:

• diuretics

• vomiting

• diarrhea

What does a HIGH POTASSIUM number indicate?

Hyperkalemia:

• renal failure

• acidosis,

• tissue breakdown

What is calcium (Ca)?

• The most abundant and one of the most important minerals in the body

•  Essential for:

  • cell signalling

  • proper functioning of muscles, nerves, and the heart

  • blood clotting

  • formation, density, and maintenance of bones and teeth

Total Calcium

This test measures the amount of calcium in the blood, which reflects the amount of total (incl ionized) calcium in the body

•  measures both the free and bound forms

Ionized Calcium

measures only the free, metabolically active form

How is calcium lost in the body and how do we measure this?

• Some calcium is lost from the body every day, filtered from the blood by the kidneys and excreted into the urine and sweat

• Measurement of the amount of calcium in the urine is used to determine how much calcium the kidneys are eliminating.

normal total calcium range:

2.10 - 2.60 mmol/L

normal ionized calcium range:

1.15 - 1.32 mmol/L

What does a LOW CALCIUM level mean?

• Hypocalcemia

  • Chronic renal failure

  • elevated phosphorus

  • primary hypoparathyroidism

  • Vitamin D deficiency

  • magnesium deficiency

  • acute pancreatitis

  • chronic alcoholism

  • loop diuretics

What does a HIGH CALCIUM level mean?

Hypercalcemia

•  Multiple myeloma or other bone cancers

• prolonged immobilization

• hyperparathyroidism

• thiazide diuretics

What is Magnesium (Mg)?

Vital for energy production, muscle contraction, nerve function and the maintenance of strong bones

normal magnesium range:

0.7 - 1.2 mmol/L

What does a LOW MAGNESIUM level mean?

Hypomagnesemia

• Chronic diarrhea

• alcoholism

• hemodialysis

• ulcerative colitis

• delirium tremens

• hypoparathyroidism

• hyperaldosteronism

• hepatic cirrhosis

• pancreatitis

• toxemia of pregnancy

What does a HIGH MAGNESIUM level mean?

Hypermagnesemia

• Oliguria

• dehydration

• Addison disease

• chronic renal failure

• diabetic acidosis

What is Blood Urea and Nitrogen(BUN)?

• waste product formed in the liver from protein breakdown

• It is carried to kidneys then filtered out of blood and excreted in the urine.

If the kidneys are not functioning properly would the BUN number be high or low?

HIGH

normal BUN range:

2.0 - 9.0 mmol/L

What is creatinine?

• A chemical waste produced by muscle metabolism

  • Creatine is part of the cycle that produces energy needed to contract muscles = creatine and creatinine are produced by the body at a relatively constant rate

normal creatinine range:

45-110 umol/L

If there is an issue with the kidneys would you expect to see a higher or lower than normal creatinine?

HIGHER

Liver Function Tests for Altered Synthesis

• Albumin

• Clotting factors (measured by Prothrombin Time or PT)

Liver Function Tests for Primary Liver Damage

• ALT

• AST

normal ALT range:

<50 U/L

normal AST range:

<36 U/L

Liver Function Tests for Altered Biliary Function

• Total bilirubin

• Alkaline Phosphatase (ALP)

• GGT

What is Lactate Dehydrogenase (LD/LDH)?

• an enzyme involved in energy production that is found in almost all of the body's cells, with the highest levels found in the cells of the heart, liver, muscles, kidneys, lungs, and in blood cells

• can be produced by bacteria

• This test measures the level of LD in the blood or sometimes other body fluids

• More of a blood test for trending tissue damage than it is diagnostic for any one condition

• Can be ordered as part of LFT’s, but not always

normal LDH range:

100-250 IU/L

What is Prothrombin Time (PT)?

a measure of how quickly blood clots

• result is the time in seconds that is required for the blood to clot

normal prothrombin time (PT) range:

11 - 13.5 secs if not on blood thinners

What is International Normalized Ratio (INR)?

a standardized blood test that measures how long the blood takes to clot

normal INR range:

0.8-1.2

What does a HIGH INR number mean?

The higher your INR is, the longer it takes your blood to clot therefore the risk of BLEEDING  increases

What does a LOW INR number mean?

The lower the INR the FASTER  the blood clots putting you at risk for CLOT FORMATION

The PT/ INR is trended when a patient is on which medication?

WARFARIN

What is the reversal agent for this medication if the INR/ PT is to high?

VITAMIN K

What is activated Partial Thromboplastin Time (aPTT)?

• Screening test that helps evaluate a person’s ability to appropriately form clots

• Measures the number of second it takes for a clot to form

normal activated partial prothrombin time (APTT):

25-35 s

aPTT is used when a patient is on which medication?

HEPARIN

What is the reversal agent for heparin?

PROTAMINE SULFATE

What is High Sensitivity Troponin

• HS -Troponin

• Troponin T 

• Can help ID patients who have experienced damage to their heart

• Normally almost undetectable in the blood

When would High Sensitivity Troponin be elevated?

in patients with stable angina even when they are without symptoms; indicates increased risk of future heart events

How soon can High Sensitivity Troponin levels be elevated and for how long?

• Levels can become elevated within 3-4h after injury

• Can remain elevated for 10-14 days following injury

normal high sensitivity troponin range:

< 18 ng/L

What is Brain Natriuretic Peptide (BNP)?

• A small protein

• Continually produced in the heart

• Released in larger quantities when the heart is having to work harder

• Supports fluid retention and volume expansion intravascularly

• Tested when heart failure is suspected

normal BNP range:

0-100 pg/ml

Normal Urinalysis

• Color: Amber yellow 

• Appearance: Clear 

• pH: 5-7

• Protein: Negative

  • HI: Kidney disease, glomerulonephritis

• Glucose: Negative

• Ketones: Negative

  • HI: Diabetes ketoacidosis, starvation, high-fat diet

• Blood: Negative

• Nitrites: Negative

  • HI: Detect Gram-negative bacterial UTI

• Ur Leukocyte Esterase: Negative