Preparation of the PatientBLOOD SPECIMEN

COLLECTION PROCESSING

BY:

Annabel Lapuz-Carungin, MD, RMT, PT, RN, RM, MAN

Preparation of the Patient

Factors might influence laboratory determinations:

1. Diurnal variation2. Exercise3. Fasting4. Diet5. Ethanol consumption6. Tobacco smoking7. Drug ingestion8. Posture

Some test requires at least 8 hours of fasting.

Blood is the most frequent body fluid used for analytical purposes.

Three general procedures for blood collection:

1. Venipuncture (blood chemistry)

2. Arterial puncture (ABG)

3. Skin puncture (pediatric client)

Technique for Venous Puncture

1. Verify requisitions

2. Client identification

3. Specimen required

(fasting/non-fasting)

4. Inform client of the procedure,

client reassurance.

5. Proper positioning of client

6. Preparation of equipment

& proper labelling

7. Selection of suitable vein for puncture.

Ideal: antecubital fossa

(median cubital & cephalic vein)

8. Cleanse site with 70% alcohol or 1% iodine-saturated swabstick

9. Apply tourniquet

10. Perform the venipuncture

(15 degree angle)

11. Release tourniquet

12. Place a sterile cotton &

apply pressure

13. Withdraw needle

14. Transfer specimen

15. Check condition of client

16. Dispose contaminated materials

NOTE: Open & close of fist during phlebotomy is of no value and may increase in potassium hence, should be avoided.

COMPLICATIONS:Prolonged application of a tourniquet results in increase blood concentration

(hemoconcentration)

1. Missed vein Hematoma

2. Excessive pull on syringe plunger collapse of small vein

3. Client’s syncope

4. Excessive bleeding

5. Vein thrombosis

6. Infection of the site of venipuncture

Failure of to obtain blood after two attempts is an indication that another phlebotomist should make an attempt.

NOTE: Draw specimens into non-additive tubes before tubes with additives.

Fill additive-containing tubes in the following order:

1. Blood culture tubes (yellow/black stopper)

2. Red stopper tube

3. Blue stopper tube

4. Green stopper tube

5. Lavender stopper tube

6. Gray stopper tube

Commonly used evacuated tubes (with the corresponding color coding and additive)

STOPPER COLOR ADDITIVE ACTION

RED None Allows blood to clot

Red/gray, red/black Contains separator material Material serves as a barrier between serum & cells

Lavender EDTA Binds calcium

Orange Thrombin Accelerates clot formation

Blue Na Citrate Binds calcium

Gray a. Na flouride/K oxalateb. Iodoacetate

Inhibits glycolytic enzyme

Green Heparin Inhibits thrombin activation

Skin Puncture

used for pediatric patients

uses a sharp lancet pierce the skin and a capillary tube for sample collection

Site:

Outer area of the bottom of the foot (Heel stick)

Fleshy part of the middle of the last phalanx of the 3rd or4th (ring) finger (Finger stick)

Fleshy part of the earlobe

Sample Processing(Pre-analytical Level)

1. Correct matching of blood collection tube(s) with the appropriate analyte request and patient/client identification labels.

2. Check if sample is acceptable for further processing Amount/volume of sample sufficient Proper anticoagulant or preservative Timing is indicated Specimen is intact Properly transported

3. Centrifuge sample to separate serum/plasma from the cells

Once processed samples should be analyzed within 4 hours;to minimize the effects of evaporation, samples should be properly capped and kept away from areas of rapid airflow, light and heat

Refrigerated at 4°C for 8 hours

Frozen at -20°C

Avoid repeated cycles of freezing and thawing.(occurs in frost-free freezers)

Sample Variables1. Physiologic consideration

a. Diurnal or circadian variationb. Exercisec. Dietd. Stresse. Gender f. Ageg. Underlying medical conditionsh. Drugs i. Posture

2. Proper patient preparation

3. Problems in collection, transportation, processing and storage

Thank You