Screening Blood Tests

Question 1

Blood collection methods

Answer 1

Venepuncture - use of needle to withdraw blood from vein

Existing in-situ line or IV catheter

Arterial blood gases - radial, brachial, femoral. Requires specialist training.

Drs, nurses, phlebotomist.

Question 2

Red top collection tube

Answer 2

No additive

Allows blood to clot and seperate to test serum

Chemistry, bilirubin, blood urea nitrogen (BUN), calcium

Question 3

Purple top collection tube

Answer 3

Ethylenediamine tetraacetic acid (EDTA) additive

To prevent blood from clotting

Complete blood cell count, platelet count

Question 4

Gray top collection tube

Answer 4

Sodium fluoride oxalate additive

To prevent glucolysis

Chemistry, glucose, lactose tolerance

Question 5

Green top collection tube

Answer 5

Heparin additive

To prevent blood from clotting when plasma needs to be tested

Chemistry, ammonia, carboxyhemoglobin

Question 6

Blue top collection tube

Answer 6

Sodium nitrate

To prevent blood from clotting when plasma needs to be tested

Hematology Prothrombin time (PT), partial thromboplastin time (PTT)

Question 7

Black top collection tube

Answer 7

Sodium citrate

Binds calcium to prevent blood clotting

Westergren erythrocyte sedimentation rate (ESR)

Question 8

Yellow gold serum separator tube

Answer 8

Citrate dextrose additive, none

Preserves red blood cells, collects serum

Blood culture chemistry

Question 9

Factors that increase risk of electrolyte imbalance

Answer 9

Infection
Diabetes and hypertension
Use of diuretics
Age
Strenuous exercise

Question 10

Symptoms of electrolyte disorders

Answer 10

Irregular heartbeat
Fatigue and lethargy
Convulsions or seizures
Nausea and vomiting
Diarrhoea or constipation
Abdominal and muscle cramping
Muscle weakness
Confusion
Headaches
Numbness and tingling

Question 11

When to request electrolytes

Answer 11

Signs or symptoms:
Oedema
Nausea and or vomiting
Weakness
Confusion
Irregular heartbeat

Management of acute or chronic conditions:
Hypertension
Heart failure
Lung disease
Liver disease
Kidney disease

Question 12

INTERPRETING RESULTS: High Sodium

Answer 12

Hypernatraemia

Early dehydration
Cushing’s syndrome
Diabetes Insipidus

Question 13

INTERPRETING RESULTS: Low Sodium

Answer 13

Hyponatraemia

Diarrhoea
Vomiting
Diuretics
Excess sweating
Kidney disease

Question 14

INTERPRETING RESULTS: High Potassium

Answer 14

Hyperkalaemia

Renal dysfunction
Addisons disease
Injury
Infection
Diabetes
Prescription drugs

Question 15

INTERPRETING RESULTS: Low Potassium

Answer 15

Hypokalaemia

Vomiting
Diarrhoea
Hyperaldosteronism

Question 16

INTERPRETING RESULTS: High Chloride

Answer 16

Hyperchloraemia

Dehydration
Metabolic acidosis
Respiratory alkalosis

Question 17

INTERPRETING RESULTS: Low Chloride

Answer 17

Hypochloraemia

Prolonged vomiting
Respiratory acidosis
Metabolic alkalosis

Question 18

INTERPRETING RESULTS: High Bicarbonate

Answer 18

Trouble maintaining pH balance (respiratory acidosis)

Question 19

INTERPRETING RESULTS: Low Bicarbonate

Answer 19

Respiratory alkalosis
Metabolic acidosis
Shock
Starvation
Kidney failure