Blood sample collection procedure with steps
- 1. PRESENTED BY: Sonali M.Sc. (Nsg.) 1st Year CON, AIIMS New Delhi BLOOD SAMPLE COLLECTION
- 2. BLOOD COLLECTION FOR TESTING There are three types of blood samples collected for the examination of blood parameters and values: • Venous blood (venous blood is collected most frequently, e.g. for erythrocyte sedimentation rate test) • Arterial blood (e.g. examination and determination of blood gases) • Capillary blood (e.g. blood glucose)
- 3. TYPES OF BLOOD SPECIMENS WHOLE BLOOD To obtain a whole blood specimen, the blood must be collected in a tube that contains an anticoagulant. The sample then does not clot. Following are examples of laboratory tests that can be performed only on whole blood. • Complete blood cell count (CBC) • Erythrocyte sedimentation rate (ESR) • Hemoglobin electrophoresis SERUM Blood that has been removed from the body will coagulate (clot) in about 20 minutes. The clot consists of the blood cells trapped in a mesh of fibrin, a product produced during the coagulation process. The remaining portion of the blood specimen is fluid and is called serum. Following are some examples. • Serum protein electrophoresis • Hepatitis B antibody
- 4. PLASMA To obtain plasma in a blood sample, the blood must be prevented from clotting. This is accomplished by drawing the blood into a tube that contains a substance called an anticoagulant. Some laboratory tests can be performed only on plasma. Following are some examples. • Prothrombin time (PT) • Activated partial thromboplastin time (aPTT) • Di-Dimer
- 5. COMMON VACUTAINER TYPES USED FOR BLOOD SAMPLE COLLECTION
- 7. ADDITIVES USED IN VACUTAINERS The following substances are types of anticoagulants. Their presence in tubes prevents the blood from clotting. • K2EDTA (potassium ethylenediamine tetra-acetic acid) • Na2EDTA (sodium ethylenediamine tetra-acetic acid) • Sodium citrate • Sodium heparin • Lithium heparin • Potassium oxalate • ACD (acid citrate dextrose) • SPS (sodium polyanethol sulfonate) • CTAD (citrate, theophylline, adenosine, dipyridamole) The following substances are other types of additives in tubes that are not anticoagulants. • Thrombin (helps the blood clot quicker) • Sodium fluoride (prevents glucose in the blood from decreasing in quantity) • Gel (during centrifugation, moves up in the tube to form a barrier between red cells and serum/plasma)
- 10. COLLECTING BLOOD FOR ROUTINE EXAMINATION DEFINITION • Obtaining blood sample by venipuncture for routine laboratory investigations. PURPOSES • To determine variations if any in blood composition • To determine any abnormality in order to aid in diagnosis
- 11. ARTICLES Tourniquet Small mackintosh with draw sheet Sterile Syringes 5ml, 10ml 20 or 23 gauge needles or vacutainer assembly Alcohol swabs Disposable gloves/clean gloves Specimen container- test tube or bottle Laboratory requisition form Dry cotton/Band- aid Adhesive tapes Sterile gauze pads Puncture proof container
- 12. PROCEDURE
- 13. Nursing action Rationale PREPROCEDURAL STEPS 1. Check the physician’s order 2. Identify the patient Ensures performance of procedure on right patient 3. Reassure the patient and explain that relatively little blood will be taken Obtains patient’s cooperation and confidence. INTRAPROCEDURAL STEPS 4. Wash hands and put on gloves Protects health care worker from possible exposure to blood. 5. Select and examine the vein, visualize the vein, including the antecubital area, wrist, dorsum (back) of the hand and top of foot (if necessary). Palpate the vein Select the vein that is visible, palpable and fixed to the surrounding tissues so that it does not roll away 6. Instruct the patient to extend his arm. Hold the arm straight at the elbow with fist clenched. Proper positioning reduces the risk of injury 7. Apply the tourniquet 5-15cm above the selected site with just sufficient pressure to obstruct venous flow A tourniquet when applied increases venous pressure and makes the vein more prominent and easier to enter 8. Cleanse the skin with alcohol swab in a circular motion; center to periphery. Allow to dry Cleansing the skin reduces the number of microorganisms
- 14. 9. Fix the chosen vein with thumb and draw the skin taut immediately below the site before inserting needle to stabilize the vein The vein may roll beneath the skin when the needle approaches its outer surface, especially in elderly and extremely thin patients 10. Hold the syringe between the thumb and last three fingers with the bavel up and directly in line with the course of the vein. Insert the needle quickly and smoothly under the skin and into the vein. 11. Obtain the blood sample by gently pulling back on the plunger Use minimal suction to prevent hemolysis of blood and collapse of vein 12. Release the tourniquet as soon as the specimen is obtained and ask the patient to open the fist. 13. Apply sterile cotton balls to puncture site without applying pressure and withdraw needle slowly along the line of vein Slow withdrawl of the needle is less painful and reduces trauma 14. Request patient to apply gentle but firm pressure to site for 2-4 minutes Firm pressure over puncture site prevents leakage of blood into surrounding tissues with subsequent hematoma development
- 15. 15. Remove the needle from the syringe as soon as possible after withdrawing blood, gently eject the blood sample into the appropriate container without forming bubbles in the test tube or bottle (some tests require container with anticoagulant) Gentle ejection of blood prevents hemolysis 16. Invert the tube gently several times to mix blood with anticoagulant where applicable. For some tests blood is allowed to coagulate in the test tube Gentle handling of specimen prevents risk of hemolysis 17. Apply band-aid/adhesive tape over the puncture site POSTPROCEDURAL STEPS 18. Label the specimen correctly and send to laboratory immediately with completed requisition forms. Specimen should reach the laboratory with the minimum of delay for optimum reliability 19. Dispose the needle and syringe in appropriate containers. Avoids possible spread of blood-borne diseases 20. Clean all spills with 10% bleach (sodium hypochlorite) solution. Remove gloves and wash hands. Avoids possible spread of blood borne diseases 21. Record in the patient’s chart the procedure and the tests for which the sample was sent to the laboratory 22. Replace the tray in the reusable articles in proper place.
- 16. POINTS TO REMEMBER • In case of difficult vein, a sterile needle must be used for each new collection attempt. • Never re-prick a site using the same needle. SPECIAL CONSIDERATIONS • Follow standard precautions for ALL patients. • Never re-use a disposable needle or instrument. • Safely dispose all sharps (needles, lancets, scalpels) after use. • Do not perform/assist invasive procedures without gathering all articles in a tray, it helps in safe transportation of the needle/syringes and blood samples. • Do not re-cap the used needles to prevent needle stick injury. • Use personal protective equipment (PPE) based on risk of the procedure.
- 17. AREAS TO AVOID WHEN CHOOSING A SITE FOR BLOOD DRAW Extensive scars from burns and surgery - it is difficult to puncture the scar tissue and obtain a specimen. The upper extremity on the side of a previous mastectomy - test results may be affected because of lymphedema. Hematoma - may cause erroneous test results. If another site is not available, collect the specimen distal to the hematoma. Intravenous therapy (IV) / blood transfusions - fluid may dilute the specimen, so collect from the opposite arm if possible. Cannula/fistula/heparin lock - blood should not be drawn from an arm with a fistula or cannula without consulting the attending physician. Edematous extremities - tissue fluid accumulation alters test results.
- 18. TECHNIQUES TO PREVENT HEMOLYSIS (WHICH CAN INTERFERE WITH MANY TESTS) Mix all tubes with anticoagulant additives gently (vigorous shaking can cause hemolysis) Avoid drawing blood from a hematoma; select another draw site. If using a needle and syringe, avoid drawing the plunger back too forcefully. Make sure the venipuncture site is dry before proceeding with draw. Avoid a probing, traumatic venipuncture. Avoid prolonged tourniquet application (no more than 2 minutes; less than 1 minute is optimal). Avoid massaging, squeezing, or probing a site. Avoid excessive fist clenching. If blood flow into tube slows, adjust needle position to remain in the center of the lumen.
- 19. COMPLICATIONS Haematoma as a result of unsuccessful puncture, or after withdrawal of the needle Phlebitis – in frequently repeated sampling Disruption of limb mobility – nerve disruption Bleeding from the injection site
- 20. NURSING RESPONSIBILITIES Prepare the client Complete lab requisition forms Collect right specimen from right patient in right container Follow the safety measures Label the specimen correctly Timely transfer of specimen to the lab Documentation of the procedure Examine patient for any complication
- 21. CONCLUSION Phlebotomy is the process of making a puncture in a vein, usually in the arm, for the purpose of drawing blood. The procedure itself is known as a venipuncture.It is essential to follow a standard procedure for the collection of blood specimens to get accurate laboratory results. Knowing the procedure or process when drawing blood is the first step to ensuring that health workers have carried out the procedure correctly and the phlebotomy (blood draw) process runs smoothly. The patient’s safety and comfort is, therefore, guaranteed.
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