6. Venous blood collection clinical laboratory investigation – basic procedures and sources of errors Flashcards
What Must You Do to AVOID Problems with Hemo-Concentration + Dilution, in the Phlebotomy Procedure?
{PPT}
Patient Seated for 15-20 Minutes
Before Blood is Drawn
How Should the Tourniquet be applied, in the Phlebotomy Procedure?
{PPT}
Enough to RESTRICT Venous Flow
NOT TIGHT to OCCLUDE Arterial Flow
What % Alcohol Must be Used, When Cleaning the Venipuncture Site, in the Phlebotomy Procedure?
{PPT}
70% Alcohol
How do you End the Phlebotomy Procedure?
{PPT}
RELEASE the Tourniquet = Blood BEGINS to Flow
Withdraw Needle ALONG WITH the Tourniquet
What is the Order of Drawing Blood?
{PPT}
1) Haemoculture
2) Serum
2) Plasma = For Haemostasis
3) ESR + Heavy Metals
4) Whole Blood = For Haematology Test
How Must You Place the Blood Sample in the Tube?
Gently Mix
Invert Tube with Anticoagulant
DO NOT Shake the tube!
What are the Common Error BEFORE Venous Puncture?
Misidentification of the Patient
Patient NOT PROPERLY Prepared = WITHOUT 12hr Starvation
Change in Body Position BEFORE Procedure
What are the Common Error DURING Venous Puncture?
- Small Needles
- Tourniquet being left on the arm for MORE THAN 1 Minute
- Venipuncture in Improper Vein Site
- Tapping on Vein
- Pumping with Fingers, while Tourniquet is Applied
1| What does Small Needles Lead to?
Haemolysis
2| What Happens If You Leave the Tourniquet on for MORE than 1 Minute?
and What does this Influence?
Local Stasis
Haemoconcentration
Influencing Results for
- Albumin
- K+
- N.O of Erythrocytes
- HCT
- HGB
- WBC
- PLT
3| What does a Venipuncture at an Improper Vein Site Lead to?
Haematoma
4| What does Tapping on the Vein Lead to?
Haemolysis = Rupturing of RBCs
Activation of Coagulation Factors
5| What does Pumping with Fingers, while Tourniquet is Applied, Lead to?
Local Acidosis
Haemolysis
INCREASING K+ and Lactate Levels by 20%
What are the Common Error AFTER Venous Puncture?
NOT Loosening the Tourniquet, AFTER entering the Vein + drawing the blood
Wrong Tubes / Anticoagulant
Wrong Order of Evacuated Collection Tubes
Short Draw = WRONG Blood : Coagulant Ratio
Mislabelling of Specimen
Exposure to Light / Extreme Temp
Improperly Timed Specimens / Delayed Delivery
What is Lipemia?
{PPT}
Serum Appears Milky or Turbid
DUE to Lipids = Improper Fasting (NOT 12hr Starvation)