CHAPTER © 2011 The McGraw-Hill Companies, Inc. All rights reserved. 5 Collecting, Processing, and Testing Blood Specimens

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Functions and Composition of Blood (cont.) 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Functions and Composition of Blood (cont.) White blood cells – leukocytes –Protect against infection –Granular Basophils Eosinophils Neutrophils –Agranular T and B lymphocytes monocytes

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Functions and Composition of Blood (cont.) 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge 1. 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.

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge ANSWER: Functions of the blood are: (list any 3) 1. Distributes oxygen, nutrients, and hormones 2. Eliminates waste products 3. Attacks infecting pathogens 4. Maintains acid-base balance 5. Regulates body temperature 2. What are three functions of blood?

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Collecting Blood Specimens 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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 Common Sites for Venipuncture

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Collecting Blood Specimens (cont.) Venipuncture complications –Hematoma Hold needle still Hold pressure on site after 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Collecting Blood Specimens (cont.) Engineered safety devices –Reduce the possibility of needlestick injuries –Types Retracting needles Hinged or sliding shields Self-blunting needles Retractable lancets

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Collecting Blood Specimens (cont.) 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge What precautions should you take when collecting a blood specimen? ANSWER: You should use Standard Precautions and appropriate personal protective equipment.

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Responding to Patient Needs Respond with sensitivity and competence Fears and concerns –Pain –Bruises or scars –Serious diagnosis –Contracting a disease from the procedure

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved –Angry or violent patients Explain need for testing Avoid arguing Do not force patient Document behavior and if patient refuses Special Considerations (cont.) Difficult patients –Difficult venipuncture – do not stick more than twice –Fainting patients – Reaction to blood draw Position to avoid injury Difficult patients –Difficult venipuncture – do not stick more than twice –Fainting patients – Reaction to blood draw Position to avoid injury

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge 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. What is one precaution you can take when drawing blood from a patient who is taking anticoagulants? Correct!

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Performing Common Blood Tests Results aid in diagnosis POLs often only perform waived tests Know office policy

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Hematologic Tests Blood counts –RBC count –White blood cells –Differential white blood cell –Platelet –Hematocrit –Hemoglobin Centrifuged Capillary Sample

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Chemical Tests Rarely performed in the POL Waived tests –Blood glucose monitoring –Hemoglobin A1c –Cholesterol tests

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Serologic Tests 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

© 2011 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge Matching: ___ Hemoglobin A1c A.ESR ___ Lysing RBCs/evaluating the colorB.Serology test ___ Shape or form of objectsC.Coagulation tests ___ Identify bleeding problemsD.Chemical test ___ Rate at which RBCs fallE.Differential ___ Percentage of each type of WBC F.Morphology ___ ELISAG.Hemoglobin ANSWER: G F E D C B A Super!

© 2011 The McGraw-Hill Companies, Inc. All rights reserved End of Chapter 48 Blood will tell, but often it tells too much. ~ Don Marquis