Collecting, Processing, and Testing Blood Specimens

1. 5 Collecting, Processing, and Testing Blood Specimens

2. Introduction • Medical assistant • Collects blood specimens • Performs waived testing • Knowledge needed • Understand circulatory system and function of blood • Appropriate supplies and equipment • How to perform and screen common blood tests

3. Role of the Medical Assistant • Phlebotomy – insertion of a needle or cannula into a vein to withdraw blood • Put the patient at ease during procedure • Process specimens and conduct testing • Complete necessary paperwork and make sure specimens are handled properly

4. Functions and Composition of Blood • Circulatory system transports blood • Heart pumps 8–12 pints of blood through 70,000 miles of vessels/day • Hematology – the study of blood

5. Functions and Composition of Blood (cont.) • Functions of blood • Distributes oxygen, nutrients, and hormones • Eliminates waste products • Attacks infecting pathogens • Maintains acid-base balance • Regulates body temperature

6. Red blood cells – erythrocytes Internal respiration Transport oxygen to cells Hemoglobin – 98% Dissolved in plasma – 2 to 3 % Hemoglobin Main component of RBCs Protein containing iron Functions and Composition of Blood (cont.)

7. White blood cells – leukocytes Protect against infection Granular Basophils Eosinophils Neutrophils Agranular T and B lymphocytes monocytes Functions and Composition of Blood (cont.)

8. Platelets – thrombocytes Fragments of cytoplasm Essential for clot formation Plasma Clear, yellow liquid Contains formed elements of blood 90% water Serum – clear, yellow liquid remaining after clot formation Functions and Composition of Blood (cont.)

9. Functions and Composition of Blood (cont.) • Blood types or groups • Presence of antigens A and B determines type • Blood also carries antibodies • Transfusions require careful matching to prevent hemolysis

10. Apply Your Knowledge • What is the role of the medical assistant related to collecting blood samples? ANSWER: The medical assistant will put the patient at ease during the procedure, process specimens, conduct testing, complete necessary paperwork, and make sure specimens are handled properly.

11. Apply Your Knowledge What are three functions of blood? ANSWER: Functions of the blood are: (list any 3) Distributes oxygen, nutrients, and hormones Eliminates waste products Attacks infecting pathogens Maintains acid-base balance Regulates body temperature Very Good!

12. Reading and interpreting the test order Review order Assemble equipment and supplies Preparing the patient Greet and identify the patient Confirm pretest preparation Explain the procedure and safety precautions Establish chain of custody Collecting Blood Specimens

13. Collecting Blood Specimens (cont.) • Use Standard Precautions and PPE as needed • Handling exposure incident • Needlestick or other exposure to blood/blood products • Report to appropriate person immediately • Wash area and apply bandage • Document date, time, people involved, type of exposure

14. Common Sites for Venipuncture Drawing Blood • Not all states permit medical assistants to draw blood • Venipuncture • Puncture of a vein • Most common sites are in the antecubital fossa and forearm

15. Venipuncture complications Hematoma Hold needle still Hold pressure on siteafter removal of needle Latex allergy Ask patient Use non-latex gloves,tourniquet, and bandages Nerve injury Know anatomy Infections Rare Clean site prior to venipuncture May not be evident for several days Collecting Blood Specimens (cont.)

16. Collecting Blood Specimens (cont.) • Equipment • Evacuation systems – use special double-pointed needle, needle holder • Needle and syringe systems • Butterfly system – winged infusion set and syringe • Collection tubes • Sealed to create a vacuum • Color-coded to identify appropriate additive

17. Engineered safety devices Reduce the possibility of needlestick injuries Types Retracting needles Hinged or sliding shields Self-blunting needles Retractable lancets Collecting Blood Specimens (cont.)

18. Capillary puncture Superficial puncture of skin with sharp point Lancets– small, disposable instruments Automatic puncturing devices Micropipettes – small, calibrated glass tubes that hold a precise volume of fluid Reagent products –chemically treated paper or dipstick Smear slides Collecting Blood Specimens (cont.)

19. Apply Your Knowledge What precautions should you take when collecting a blood specimen? ANSWER: You should use Standard Precautions and appropriate personal protective equipment. excellent!

20. Responding to Patient Needs • Respond with sensitivity and competence • Fears and concerns • Pain • Bruises or scars • Serious diagnosis • Contracting a disease from the procedure

21. Special Considerations • Children • Talk with parent or caregiver first • Address child directly • Speak in a calm, soothing voice • Explain the procedure briefly in terms they can understand • Keep child informed of status during the procedure

22. Special Considerations (cont.) • Elderly • Prone to bruising • Difficult to obtain an adequate sample • Speak clearly in a low-pitched voice • Allow adequate time for patient to respond to questions

23. Special Considerations (cont.) • Risk of bleeding • Hemophilia or taking blood-thinning medication • Hold site for at least 5 minutes • Contact physician if bleeding does not stop

24. Difficult patients Difficult venipuncture – do not stick more than twice Fainting patients – Reaction to blood draw Position to avoid injury Special Considerations (cont.) • Difficult patients • Difficult venipuncture – do not stick more than twice • Fainting patients – • Reaction to blood draw • Position to avoid injury • Angry or violent patients • Explain need for testing • Avoid arguing • Do not force patient • Document behavior and if patient refuses

25. Apply Your Knowledge What is one precaution you can take when drawing blood from a patient who is taking anticoagulants? ANSWER: After drawing blood on a patient taking anticoagulants, you should hold a cotton ball over the puncture site for at least 5 minutes, monitor the site carefully, and notify the physician if bleeding does not stop. Correct!

26. Performing Common Blood Tests • Results aid in diagnosis • POLs often only perform waived tests • Know office policy

27. Performing Common Blood Tests(cont.) • Chemicals in lab • Anticoagulants – keep blood in uncoagulated state • Serum separators – form a gel-like barrier between serum and clot in coagulated sample • Stains – color particular cells

28. Centrifuged Capillary Sample Hematologic Tests • Blood counts • RBC count • White blood cells • Differential white blood cell • Platelet • Hematocrit • Hemoglobin

29. Hematologic Tests (cont.) • Morphologic studies • Morphology– study of shape and form of objects • Requires special training • Coagulation tests • Identification of potential bleeding problems • Monitor therapeutic drug levels for anticoagulants • PT and PTT

30. Hematologic Tests (cont.) • Erythrocyte sedimentation rate • Measures rate of RBCs falling to the bottom of the blood sample • Must be performed on a fresh sample • Tube must contain an anticoagulant • Read after one hour • Recorded as mm/hr

31. Chemical Tests • Rarely performed in the POL • Waived tests • Blood glucose monitoring • Hemoglobin A1c • Cholesterol tests

32. Introduction of an antigen or antibody into a specimen and detection of a reaction to it Immunoassays Western blot Radioimmunoassay (RIA) Enzyme-linked immunosorbent assay (ELISA) Immunofluorescent antibody (IFA) test Rapid screening tests Infectious mononucleosis HIV Helicobacter pylori Serologic Tests

33. Apply Your Knowledge Matching: ___ Hemoglobin A1c A. ESR ___ Lysing RBCs/evaluating the color B. Serology test ___ Shape or form of objects C. Coagulation tests ___ Identify bleeding problems D. Chemical test ___ Rate at which RBCs fall E. Differential ___ Percentage of each type of WBC F. Morphology ___ ELISA G. Hemoglobin ANSWER: D G F C A E B Super!

34. End of Chapter 48 • Blood will tell, but often it tells too much. • ~ Don Marquis