Phlebotomy Lec Flashcards
collection of minute sample of blood through capillary puncture
MICROSAMPLING
INFANTS up to _ year of age
- Plantar surface of the big toe
- Median or ______ side of the heel
- Depth of puncture: up to ___ mm
INFANTS up to 1 year of age - Plantar surface of the big toe
- Median or lateral side of the heel
- Depth of puncture: up to 2.4 mm
ADULTS:
- ______ or ____ finger
- Puncture must be slightly off-center, _________________ to the fingerprint
- Margin of the earlobe
- Depth of puncture: up to ___ mm
ADULTS:
- Middle or ring finger
- Puncture must be slightly off-center, perpendicular to the fingerprint
- Margin of the earlobe
- Depth of puncture: up to 3.1 mm
collection of a greater volume of blood from the veins or arteries
MACROSAMPLING
- Collection of arterial blood for blood gas analysis or ____________ determination
- Common sites: _______________, ________________, ___________________
ARTERIAL PUNCTURE:
- Collection of arterial blood for blood gas analysis or blood pH determination
- Common sites: radial artery, brachial artery, femoral artery
- Collection of venous blood
SITES:
-
-
-
- -
VENIPUNCTURE:
- Collection of venous blood
SITES:
Infants up to 18 months
- External jugular vein
- Superior longitudinal sinus
- Temporal vein
18 months to 3 years
- Popliteal vein
- Femoral vein
- Long saphenous vein
- Ankle vein
3 years to adulthood
- Veins on the antecubital fossa
- Wrist vein
- Veins on the dorsal of hands & feet
– use of syringes
- The hub of the needle is color-coded, corresponding to its gauge
- The ______ the gauge, the ________ the bore of the needle
OPEN SYSTEM
– use of syringes
- The hub of the needle is color-coded, corresponding to its gauge
- The lower the gauge, the bigger the bore of the needle
– use of an evacuated system (evacuated tube, two-way needle and adapter)
- Evacuated tubes are equipped with a hemogard (color-coded in accordance to the additive
present)
- Multiple sampling can be carried out
CLOSED SYSTEM
– use of an evacuated system (evacuated tube, two-way needle and adapter)
- Evacuated tubes are equipped with a hemogard (color-coded in accordance to the additive
present)
- Multiple sampling can be carried out
liquid portion of clotted blood
SERUM
liquid portion of anti-coagulated blood
PLASMA
preparation involves the removal of proteins from any biological
specimen to prevent direct colorimetric interference by the formation of zwitterions at isoelectric pH where proteins exhibit maximum precipitation and minimum solubility
PROTEIN-FREE FILTRATE (PFF)
METHODS of PFF PREPARATION:
Physical Methods, Chemical Methods
Physical Methods:
1.
2.
Physical Methods:
1. Heat
2. Ultracentrifugation
Chemical Methods
(ACID Method)
1. ______________
▪ Specimen: whole blood; plasma/serum
▪ 2/3 N Sulfuric acid
▪ 10% sodium tungstate
- _____________
▪ Specimen: serum
▪ N/12 Sulfuric acid
▪ 10% sodium tungstate - __________ - makes use of a pre-mixed acid
- TCA (__)
(BASE Method)
1. ________________: 0.3N Ba(OH)2 & 5% ZnSO4
Chemical Methods
(ACID Method)
1. Folin-Wu
▪ Specimen: whole blood; plasma/serum
▪ 2/3 N Sulfuric acid
▪ 10% sodium tungstate
2. Hayden’s method
▪ Specimen: serum
▪ N/12 Sulfuric acid
▪ 10% sodium tungstate
3. Van Slyke - makes use of a pre-mixed acid
4. TCA (5%)
(BASE Method)
1. Nelson-Somogyi : 0.3N Ba(OH)2 & 5% ZnSO4
CONTAMINATION of SPECIMEN
❖ ____________________ in tubes
❖ ________________ in IV tubing and tube stoppers
❖ _______________ & glass tubes
❖ _______________: use lead-free, acid-washed containers
CONTAMINATION of SPECIMEN
❖ residual detergent in tubes
❖ Plasticizers in IV tubing and tube stoppers
❖ Cork stoppers & glass tubes
❖ Lead analysis: use lead-free, acid-washed containers
Serum or plasma should be separated from cells within _ ________ of collection (unless collected in a gel separator tube).
Serum or plasma should be separated from cells within 2 hours of collection (unless collected in a gel separator tube).
Rate of glycolysis:
At ___ temperature – _ mg/dL
At ____ temperature – _ mg/dL
Rate of glycolysis:
At ref temperature – 2 mg/dL
At room temperature – 7 mg/dL
❖ Allow _______ top tubes to clot sufficiently (________ minutes) before centrifugation to avoid fibrin strands.
❖ Centrifuge 10 ± 5 minutes at _____________ × g.
❖ Keep tubes capped during ______________
❖ ___________ specimens can be ultracentrifuged
❖ Allow red top tubes to clot sufficiently (20-30 minutes) before centrifugation to avoid fibrin strands.
❖ Centrifuge 10 ± 5 minutes at 1000-1200 × g.
❖ Keep tubes capped during centrifugation
❖ Lipemic specimens can be ultracentrifuged
SPECIMEN HANDLING REQUIREMENTS:
- Fasting
- Timed
- Peak/ Post- dose
- Trough/ Pre- dose
- Chilled
- Keep warm
- Protect from light
- Chain of custody
• Patients should not eat or drink anything (NPO) except water
• Glucose determination: 6 – 8 hours fasting
• Lipid Profile: 10 – 12 hours fasting
FASTING
• Specimen to be collected at a specified time
• Label the tube with the time the specimen was drawn
• Tests for Cardiac profile
TIME
• Specimen collected when the highest serum concentration of a drug is anticipated
• Drawn 30 minutes to 1 hour after administration of the drug
• Therapeutic Drug Monitoring
PEAK / Post-dose
• Specimen collected when the lowest serum concentration of a drug is expected, usually before
the next dose is administered
TROUGH / Pre-dose
• Chilling the specimen to ___________ the metabolic process that will continue after blood is
drawn
• Placed in crushed ice & water for even cooling
• _______________ determination, blood gas analysis & Coagulation studies
CHILLED
• Chilling the specimen to slow down the metabolic process that will continue after blood is
drawn
• Placed in crushed ice & water for even cooling
• Blood ammonia determination, blood gas analysis & Coagulation studies
• Keep specimen at body temperature or close to 37°C (incubator)
• For __________________
KEEP WARM
• Keep specimen at body temperature or close to 37°C (incubator)
• For cold agglutinins
• Specimen should be wrapped in aluminum foil or a light-inhibiting container should be used
• Bilirubin, Vit. B12, Carotene
PROTECT FROM LIGHT
• For legal or forensic proceedings, sample may be used as piece of evidence
• Documentation of specimen handling begins with patient identification and continues until
testing is complete
o It must include date, time and identification of handler, all to be done in the presence of
a witness
• DNA Analysis, Drug testing, Alcohol levels
CHAIN OF CUSTODY
REASONS FOR SPECIMENT REJECTION
:
REASONS FOR SPECIMENT REJECTION
✓ Hemolysis
✓ Lipemic / Lactescent serum
✓ Clots in an anti-coagulated specimen
✓ Partially-filled tubes
✓ Improper transport conditions
✓ Discrepancies b/w requisition & specimen label
✓ Unlabeled or mislabeled specimen
✓ Contaminated specimen/Leaking container
SPECIMEN INTERFERENCES:
- Hemolysis
- Anticoagulants and preservatives
- Icteric Serum/ Jaundiced Serum
- Lactescent serum/ milky serum/ turbid serum
- Partially-filled tubes
- Specimen contamination
- Destruction of RBCs result in a plasma or serum appearing pink to red
- Hemoglobin concentration: exceeds 200 mg/L
HEMOLYSIS
2 hemolysis
In-vivo hemolysis
In-vitro hemolysis
Hemolysis
Interferes with:
▪ Enzyme and electrolyte assays (K+
, Zinc and Mg+2)
▪ Serum albumin (↑): __________________
▪ Serum protein (↑): __________________
▪ Serum bilirubin (↓): _______________
Hemolysis
Interferes with:
▪ Enzyme and electrolyte assays (K+
, Zinc and Mg+2)
▪ Serum albumin (↑): Bromcresol Green method
▪ Serum protein (↑): Biuret method
▪ Serum bilirubin (↓): Diazo method
o Potassium oxalate – dilution of plasma owing to water transport from the cells
o Anticoagulants that chelate calcium will inhibit various plasma enzyme activities
o Oxalates or citrates inhibit amylase activity
o Oxalates inhibit Lactate dehydrogenase and Acid phosphatase
o EDTA, oxalates and citrates will cause a decrease in calcium concentration
ANTICOAGULANTS and PRESERVATIVES
o Potassium oxalate – dilution of plasma owing to water transport from the cells
o Anticoagulants that chelate calcium will inhibit various plasma enzyme activities
o Oxalates or citrates inhibit amylase activity
o Oxalates inhibit Lactate dehydrogenase and Acid phosphatase
o EDTA, oxalates and citrates will cause a decrease in calcium concentration
ICTERIC SERUM / JAUNDICED SERUM
o Bilirubin interferes with the ff:
▪ Albumin assay: ______________
▪ Cholesterol assay: ______________
▪ Glucose determination: ___________
▪ Total Protein determination: _________
ICTERIC SERUM / JAUNDICED SERUM
o Bilirubin interferes with the ff:
▪ Albumin assay: HABA method
▪ Cholesterol assay: Ferric chloride reagents
▪ Glucose determination: ortho-toluidine method
▪ Total Protein determination: Biuret method
LACTESCENT SERUM / MILKY SERUM / TURBID SERUM
o Interferes with the ff:
▪ Albumin assay: _____________
▪ Calcium : ______________
▪ Inorganic phosphates: ____________
▪ CK, bilirubin and total protein levels decrease
▪ Inhibits the activity of amylase, uricase and urease
LACTESCENT SERUM / MILKY SERUM / TURBID SERUM
o Interferes with the ff:
▪ Albumin assay: Bromcresol Green method
▪ Calcium : Cresolphthalein method
▪ Inorganic phosphates: Ammonium molybdate
▪ CK, bilirubin and total protein levels decrease
▪ Inhibits the activity of amylase, uricase and urease
o For proper ratio of blood to anti-coagulant to be achieved, all tubes should be filled until the
vacuum is exhausted
o Most important for Coagulation studies
PARTIALLY-FILLED TUBES
o Improper application of antiseptic on the site prior to venipuncture, or traces of Povidone iodine on
the site of puncture
o Aseptic technique is very important for blood cultures.
o Iodine increases K+ and Uric acid
SPECIMEN CONTAMINATION
EXERCISE
______________________: immediate fall and then subsequent increase in the concentration of free fatty
acids
______________________: Increase in activities of muscle enzymes such as Creatine kinase, aldolase,
AST, and Lactate dehydrogenase
___________________________:
- Changes the levels of sex hormones
- During a six-month training, there is an increase in the mean plasma testosterone
concentration by 21%, the androstenedione concentration by 25%
EXERCISE
Transient Effects: immediate fall and then subsequent increase in the concentration of free fatty
acids
Longer-lasting Effects: Increase in activities of muscle enzymes such as Creatine kinase, aldolase,
AST, and Lactate dehydrogenase
Long-term physical training:
- Changes the levels of sex hormones
- During a six-month training, there is an increase in the mean plasma testosterone
concentration by 21%, the androstenedione concentration by 25%
An 8 – 12 hour fasting is a must (GNFH or General Normal Fasting
Hours) to ensure that laboratory measurements are compatible with reference values
PROLONGED FASTING
Increase in the plasma concentration of potassium and triglycerides
DIET
Increase in plasma concentration of lactate, urate and the metabolites of
ethanol namely acetaldehyde and acetate
ETHANOL INGESTION
Up to 80% increase in carboxyhemoglobin
TOBACCO SMOKING
Obtain specimen in a supine or upright sitting position
POSTURE
DIURNAL VARIATION:
➢ Lower at ______:
• ACTH, Renin, Aldosterone, Insulin
➢ Higher in the _________ & _________:
• GH, ACP
➢ Iron: peaks ____ to ____________ & decreases during the ___
DIURNAL VARIATION:
➢ Lower at night:
• ACTH, Renin, Aldosterone, Insulin
➢ Higher in the afternoon & evening:
• GH, ACP
➢ Iron: peaks early to late morning & decreases during the day
➢ Increased cortisol, aldosterone, catecholamine, glucagon and insulin
➢ Stress affects adrenal hormone secretion. Anxiety resulting in hyperventilation prior to venipuncture
will lead to disturbances in acid-base balance, an increase in the serum lactate concentration, and
non-esterified fatty acids.
SHOCK and TRAUMA
➢ Blacks have increased CK, aldolase, and LDH
SKIN COLOR
➢ Increased cholesterol, protein, albumin, fibrinogen, Mg, Cl-
, Na+, and PO4
MENSTRUAL CYCLE
