Lecture Clinical procedures for medical assisting (4/e): Chapter 17 – Booth, Whicker, Wyman

Chapter 17 - Collecting, processing, and testing blood specimens. In many health-care settings, the medical assistant is responsible for collecting blood specimens from patients and even performs some testing in the waived category. In order to properly collect the specimens, you will need to review the circulatory system and the function of blood. You will be introduced in this chapter to venipuncture and capillary collection procedures, and you will learn the appropriate supplies and equipment needed to perform these procedures.

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17.3 Explain the importance of confirming patients’

identities and correctly identifying blood samples.

17.4 Describe how to perform venipuncture and

capillary puncture procedures

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17.5 Identify the equipment and supplies required

for blood-drawing procedures.

17.6 Discuss the correct procedures for disposing

of waste generated during blood-drawing procedures.

17.7 Discuss common fears and concerns of

patients and how to ease these fears.

Learning Outcomes (cont.)

17.8 Develop techniques for helping patients with

special needs, including children, the elderly, patients at risk for uncontrolled bleeding, and difficult patients.

17.9 Identify common blood tests and explain

their purposes.

17.10Perform certain blood tests

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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

Role of the Medical Assistant

• Process specimens and conduct testing

• Complete necessary paperwork and make

sure specimens are handled properly

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Functions and Composition of Blood

• Circulatory system transports blood

– Heart pumps 8–12 pints of blood

through 70,000 miles

of vessels/day

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

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Functions and Composition of Blood (cont.)

• Red blood cells – erythrocytes

Functions and Composition of Blood (cont.)

• White blood cells – leukocytes

– Protect against infection

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Functions and Composition of Blood (cont.)

• Platelets –

thrombocytes

– Fragments of

cytoplasm– Essential for clot

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

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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.

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?

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Collecting Blood Specimens

• Preparing the patient

– Greet and identify the patient

– Confirm pretest preparation

– Explain the procedure and safety precautions– Establish chain of

custody

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

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– Most common sites

are in the antecubital fossa and forearm

Common Sites for Venipuncture

Collecting Blood Specimens (cont.)

• Venipuncture

complications

– Hematoma

• Hold needle still

• Hold pressure on site after removal of

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• 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

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

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Apply Your Knowledge

What precautions should you take when collecting

a blood specimen?

ANSWER: You should use Standard Precautions and

appropriate personal protective equipment.

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Responding to Patient Needs

• Respond with sensitivity and competence

• Fears and concerns

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

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• 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

Special Considerations (cont.)

stop

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– Angry or violent patients

• Explain need for testing

• Avoid arguing

• Do not force patient

• Document behavior and if patient

– 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

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!

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Performing Common Blood Tests

• Results aid in diagnosis

• POLs often only perform waived tests

• Know office policy

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

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Hematologic Tests

• Blood counts

– RBC count

– White blood cells

– Differential white blood cell

– Platelet

– Hematocrit

– Hemoglobin Centrifuged Capillary Sample

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

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• 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

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immunosorbent assay (ELISA) – Immunofluorescent

antibody (IFA) test

• Rapid screening tests

– Infectious mononucleosis – HIV

– Helicobacter pylori

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

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In Summary

17.1 Blood is composed of plasma (the liquid portion) and

formed elements Blood serves as a transport medium for oxygen, nutrients, hormones, and waste products and also attacks infecting organisms,

maintains acid-base balance, and regulates body temperature

17.2 Blood is collected by one of two means: venipuncture

or capillary puncture Venipuncture is the process of obtaining a blood sample from a vein, and capillary puncture is the process of obtaining blood from a superficial skin puncture

In Summary (cont.)

17.3 It is essential that a patient’s identity be confirmed

before a blood sample is collected Correctly identifying the blood sample with the patient’s name ensures that the correct test will be done for the

correct patient

17.4 Venipuncture is performed by cleansing the skin in

the antecubital space, applying a tourniquet above the space, inserting a needle into the vein in the space, and withdrawing blood by way of an evacuated tube

Capillary puncture involves cleansing the skin on the finger, sticking the finger with a safety lancet, and

applying the drop of blood to a slide or in a small tube

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17.5 The supplies needed to perform a venipuncture

include VACUTAINER components (safety needle, needle holder/adapter, collection tubes), antiseptic and cotton balls or antiseptic wipes, tourniquet, sterile gauze squares, and sterile adhesive bandages

Capillary puncture requires capillary puncture device (a safety lancet or an automatic puncture device such

as Autolet or Glucolet), antiseptic and cotton balls or antiseptic wipes, sterile gauze squares, sterile

adhesive bandages, reagent strips, micropipettes, and smear slides

In Summary (cont.)

17.6 All waste generated during blood-drawing procedures

should be disposed of immediately Sharps should be placed in the sharps container after activating the

safety device, and gloves, gauze, and other disposable supplies should be placed in a biohazard container

17.7 Patients are often concerned about pain, bruising,

and scarring when having blood drawn They are sometimes afraid that they may have a serious disease, especially if large amounts of blood are drawn Good communication by the medical assistant

is the key to easing these fears

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17.8 There are always patients who will have special

needs, including children, the elderly, patients who have bleeding disorders, and difficult patients Each patient will present a special set of challenges and should be treated with the utmost care and concern

17.9 The most common tests performed in a physician’s

office laboratory include hematologic tests, chemical tests, and serologic tests

In Summary (cont.)

17.10 Hematologic, chemical, and serologic tests require

special care when performing them The medical assistant should review the manufacturer’s

instructions carefully for important information about correctly performing each test

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