Hematology I Laboratory Manual - Methods Of Blood Collection PDF

HEMATOLOGY I LABORATORY MANUAL Name: Date: Section: Score: Group: EXPERIMENT 1 METHODS OF BLOOD COLLECTION There are several methods of obtaining blood specimens. These methods include skin puncture) venipuncture, and arterial puncture! Capillary blood is commonly obtained using skin punctur...

HEMATOLOGY I LABORATORY MANUAL Name: Date: Section: Score: Group: EXPERIMENT 1 METHODS OF BLOOD COLLECTION There are several methods of obtaining blood specimens. These methods include skin puncture) venipuncture, and arterial puncture! Capillary blood is commonly obtained using skin puncture, venous blood by venipuncture, and arterial blood by arterial puncture. Arterial blood extraction is not included in current medical technology practice in the Philippines. Objectives: 1. Identify the usual and alternate sites for capillary, venous, and arterial blood extraction 2. Observe standard precautions during phlebotomy 3. Demonstrate the proper collection of capillary and venous blood from patients MATERIALS: Cotton balls 70% isopropyl alcohol Disposable lancet Tourniquet Syringe with needle (20-21 gauge) Adaptor Two-way needle Evacuated tubes (assorted) SKIN PUNCTURE FOR ADULTS Peripheral blood is obtained from the tip of the 3rd or 4th nger or the earlobe in adults. PROCEDURE: 1. Wipe the area with a cotton ball soaked in 70% isopropyl alcohol. 2. Allow the site to air-dry or pat-dry with sterile cotton. 3. Puncture the preferred site with a sterile disposable lancet. The puncture is ideally 2-3 mm. in depth. 4. Wipe off the rst drop of blood and collect the subsequent drops. Avoid squeezing the puncture site, as this will alter the composition of the blood. 5. NOTE: Dif culty in obtaining blood can be relieved by putting warm compress on the site. VENIPUNCTURE Venipuncture is essential for tests that require anticoagulation (except for microtechniques) and when a large quantity of blood is needed. It is the most convenient method of blood collection because it reduces the number and variety of apparatus required. Venous blood is usually obtained from the antecubital veins, namely the median cubital, the cephalic, and the basilic veins'(Fig. 1.1). Venipuncture can be performed using the syringe method or the evacuated tube method. fi fi fi 1 HEMATOLOGY I LABORATORY MANUAL PROCEDURE FOR SYRINGE METHOD 1. Apply the tourniquet 3-4 inches above the puncture site in a half-knot manner to congest the vein (Fig. 1.2). Ask the patient to open and close the hand several times. 2. Cleanse the puncture site with 70% isopropyl alcohol. Allow the site to dry. Puncture the vein with a sterile 20-21 gauge needle attached to a syringe at a 15° angle and depth of about 0.5-1 cm. 3. Loosen the tourniquet and gently aspirate the blood. 4. After obtaining the required quantity of blood, place sterile gauze or cotton over the puncture site then withdraw the needle. Apply pressure to stop bleeding. Never ex the arm. 5. NOTE: If bleeding is not arrested, elevate the arm and apply more pressure. Stay with the patient until the bleeding stops. Detach the needle from the syringe and transfer the blood along the side of an appropriate test tube. If the tube is anticoagulated, mix the tube with blood by gentle inversion. PROCEDURE FOR EVACUATED TUBE METHOD 1. Attach the two-way needle to the adaptor. Prepare the evacuated tubes. 2. Apply the tourniquet 3-4 inches above the site of puncture. 3. Cleanse the site with 70% isopropyl alcohol. Allow the site to dry. Puncture the vein with the two-way needle attached to the adaptor. Push the tube into the adaptor until the other side of the needle penetrates the evacuated tube, making sure that the needle remains in position in the vein. 4. Loosen the tourniquet and withdraw the needle when blood has lled the tube to its proper volume. 5. Gently invert the tube several times for proper mixing if the tube is anticoagulated. 6. NOTE: For multiple blood draws, remove the tube from the adaptor without withdrawing the needle and push the succeeding tubes into the adaptor. PROCEDURE FOR TWO-SYRINGE METHOD 1. Perform steps 1-3 of the procedure for the syringe method. 2. Place sterile gauze or cotton below the hub of the needle to prevent spillage of blood. 3. Remove the syringe after aspirating 3 mL of blood, taking care not needle from the vein. to dislodge the 4. Attach a second syringe and aspirate the required amount of blood. 5. Perform steps 4-5 of the procedure for the syringe method. 6. NOTE: The two-syringe method is recommended for whole blood clotting time technique. EXTERNAL JUGULAR VEIN PUNCTURE IN INFANTS 1. Wrap the infant in a sheet so that his/her arms are immovable along the side of the body. fi fl 2 HEMATOLOGY I LABORATORY MANUAL 2. Position the infant on the dorsal side on the examining table so that his/her head hangs over the edge of the table as an assistant steadies the infant's body. 3. Support the infant's head and turn it to one side. This is done by another assistant. 4. NOTE: When the infant cries, the external jugular vein becomes prominent. The external jugular vein runs from an angle of the mandible to the submandibular area. (Fig. 1.4) 5. Sterilize the area and follow the procedure in obtaining venous blood. BLOOD COLLECTION THROUGH A CENTRAL VENOUS ACCESS DEVICE (CVAD) Central venous access devices (CVADs) are thin, exible, hollow tubes inserted and positioned a vein in order to access the bloodstream for the delivery of therapies (Fig. 1.5). There are two types of CVAD available: catheter and port/ Catheters like peripherally inserted central catheters (PICCs) have one end positioned externally while ports/are surgically placed internally, requiring the use of a special type of needle in order to enter the vein. PROCEDURE FOR BLOOD COLLECTION FROM CVAD A. DISCARD METHOD: 1. Aspirate 3-6 mL of blood from the CVAD using a syringe or evacuated tube. Discard the initial sample collected. 2. Draw the minimum amount of blood needed for the laboratory determination using another syringe or evacuated tube. 3. Flush the CVAD with normal saline solution. fl 3 HEMATOLOGY I LABORATORY MANUAL B. PUSH-PULL METHOD: 1. Use a 10 mL syringe to ush the CVAD with normal saline solution. 2. Aspirate 6 mL of blood using the same syringe. 3. Push it back to the CVAD. 4. Repeat steps 1-3 three more times. 5. Remove the syringe, and then use a new one to collect the required amount of blood 6. Flush the CVAD with normal saline solution. C. RE-INFUSION METHOD 1. Aspirate 3=6 mL of blood from the CVAD using a syringe or evacuated tube. DO not discard the initial sample collected. Set aside the initial specimen and sterile cap. 2. Draw the minimum amount of blood needed for the laboratory determination using another syringe or evacuated tube. 3. Re-infuse the initial specimen into the CVAD. ARTERIAL PUNCTURE 1. Sterilize the puncture site. 2. Palpate the artery using the index and middle ngers of the non-working hand. Be sure the ngers have been previously sterilized. 3. Once the artery is located, move the ngers 3-4 cm apart. The artery would be midway between the ngers. 4. At an angle of 35°=409, insert the needle into the site continuously until a ash of blood 5. appears on the hub of the needle. Blood then lls the syringe in a pulsating manner. 6. When the necessary amount of blood is collected, withdraw the needle and immediately apply pressure on the puncture site. 7. Continue applying pressure until bleeding ceases completely. This would usually take 5 minutes. PREVENTION OF HEMOLYSIS DURING BLOOD COLLECTION 1. Skin puncture 1.1.Use a sharp lancet. 1.2.Avoid squeezing the area near the site. 2. Venipuncture 2.1.Use a sharp, smooth needle. 2.2.Penetrate the uppermost wall of the vein fully. 2.3.Check and make sure the tourniquet is not 2.4.Aspirate the blood gently. too tight when aspirating blood. 2.5.Remove the needle before transferring the blood to tubes (in case of syringe method). 2.6.Mix the tube by gentle inversion if the tubes contain additives. 2.7.serum is needed, do not rim and centrifuge the blood until a clot has formed. 3. Arterial puncture 3.1.Use a sharp needle. 3.2.Avoid excessive needle manipulation. fi fi fl fi fi fi fl 4 HEMATOLOGY I LABORATORY MANUAL Name: Date: Section: Group: Score: REVIEW QUESTIONS 1. Mention six ways of making the veins prominent. 2. Give the correct order of draw of evacuated tubes used when doing a multi-draw collection. 3. What are the disadvantages of skin puncture? 4. Enumerate the sites for venipuncture. 5. De ne hemoconcentration, thrombophlebitis, and hematoma. 6. What are the causes of hematoma? fi 5