Medical Laboratory Sciences Practice Flashcards

Flashcards covering hand hygiene, PPE, vein site selection, phlebotomy equipment, and order of draw for Medical Laboratory Sciences.

What are the four general categories of hazards laboratory staff are exposed to besides Act-of-God occurrences?

Biological, Chemical, Radiation, and Ergonomic / Environmental Hazards.

Identify four types of biological entities that can cause injury to an unprotected individual.

Bacteria, Viruses, Parasites, and Fungi.

What are the four primary routes through which exposure to biological hazards occurs?

Ingestion, Inoculation, Tactile Contamination, and Inhalation.

Name the six components of the Chain of Infection.

1. Infectious Agents/Microorganisms, 2. Reservoir/Source, 3. Portal of Exit, 4. Modes of Transport, 5. Portal of Entry, 6. Susceptible Host.

What factors affect the risk of an infectious agent causing disease?

Virulence, pathogenicity, and the ability to enter the host.

Define a 'Reservoir' in the chain of infection.

The environment or habitat where a pathogen can live and multiply.

What does the term OPIM stand for and what are some examples?

Other potentially infectious material; examples include seminal fluid, joint fluid, saliva, urine, or any body fluid contaminated with blood.

What is the difference between direct and indirect transmission modes?

Direct transmission includes airborne, droplet, contact, or bites; indirect transmission involve fomites (contaminated equipment), vectors, food, or water.

What is the most important practice to reduce the transmission of infectious agents in healthcare?

Hand hygiene.

When are alcohol-based handrubs preferable to soap and water?

In the absence of visible soiling of hands.

Why is it recommended that healthcare workers avoid wearing artificial nails?

They tend to harbor more pathogenic organisms, especially gram-negative bacilli and yeasts, in the subungual area.

What is the recommended duration for hand hygiene when using alcohol-based handrubs?

$20-30\text{ seconds}$.

What are the three main purposes of using masks or respirators?

Protection for the healthcare worker, patient protection during sterile techniques, and source control for coughing patients.

In the context of respirators, what does the letter 'N' signify?

Not Oil Resistant.

What is the filter efficiency level of an N95 respirator?

$95\%\text{ of airborne particles}$.

What filter efficiency level is associated with HEPA-level respirators (N100)?

$99.97\%$.

What are the three categories of oil resistance for respirators?

N (Not Oil Resistant), R (Oil Resistant), and P (Oil Proof).

Why are personal eyeglasses not considered adequate eye protection by NIOSH?

They do not meet the standards for protecting sensitive areas from liquid sprays, droplets, and splashes.

What is the correct sequence for donning PPE?

1. Gown, 2. Mask, 3. Goggles, 4. Gloves.

What is the correct sequence for doffing (removing) PPE?

1. Gloves, 2. Goggles, 3. Gown, 4. Mask.

How should a contaminated gown be handled during removal?

The outer side is turned inward, rolled into a bundle, and discarded into a designated container.

What is the 'fishing' technique used for in the laboratory setting?

A one-handed technique to safely recap a needle by guiding the cap onto the needle against a solid surface.

Define the Human Circulatory System.

A collection of structures through which oxygen and nutrient-rich blood flows to all tissues for metabolism and growth, and to remove metabolic wastes.

What is the primary function of a tourniquet in venipuncture?

It impedes venous blood flow, causing blood to accumulate in the veins and making them easier to locate.

Identify the three layers of a blood vessel.

Tunica intima, Tunica media, and Tunica externa.

Compare the Tunica externa in arteries versus veins.

In arteries, it is relatively thin; in veins, it is the thickest layer.

Describe the location of the antecubital fossa.

On the anterior surface of the arm, just below the bend of the elbow.

Name the first-choice vein for venipuncture and its characteristics.

Median Cubital Vein; it is large, well-anchored, and easy to palpate.

Which vein is the second choice for venipuncture and where is it located?

Cephalic Vein; located on the lateral (thumb) side of the antecubital fossa.

Which vein is the third choice for venipuncture and why is it used with caution?

Basilic Vein; used with caution due to its proximity to nerves and the brachial artery.

Where should a phlebotomist place their hands while identifying a patient and preparing for venipuncture?

Hand hygiene should be practiced and clean gloves applied in front of the patient.

At what distance above the venipuncture site should a tourniquet be positioned?

$3-4\text{ inches}$.

What is the maximum recommended time for a tourniquet to remain on a patient's arm?

$1\text{ minute}$.

According to CLSI, how long should a tourniquet be released before reapplication?

$2\text{ minutes}$.

Why is the non-dominant hand used for palpating veins?

It tends to be more sensitive as the dominant hand is constantly exposed to various activities.

What structures distinguish veins from tendons and arteries during palpation?

Veins feel spongy and tube-like; tendons are rigid; arteries produce a pulse.

What device is used for patients with a latex allergy?

A seraket (a latex-free tourniquet).

When collecting blood from the dorsum of the hand, where is the tourniquet applied?

Exactly right above the bone near the radiocarpal twist.

What is the function of the Luer Lock on a syringe?

It ensures a secure connection with the needle to prevent leaks.

What is the 'bevel' of a needle and its purpose?

The slanted tip that facilitates smooth skin penetration and prevents coring out a tissue plug.

What is the purpose of the 'rubber sleeve' (rubber sheath) on a multisample needle?

It serves as a valve to prevent blood from leaking into the adaptor while changing tubes.

List three advantages of the Evacuated Tube System (ETS) over the syringe method.

Closed system safety, faster multiple sample collection, and accurate blood-to-additive ratio.

When is the syringe method preferred over the ETS?

For patients with small, fragile, or difficult veins where manual control of suction pressure is needed to prevent vein collapse.

By what percentage can gloves reduce the volume of blood on a sharp?

$46-86\%$.

What is the order of draw mnemonic mentioned in the notes?

'You Better Remember God’s Good Loving Grace'.

What additive is in a Yellow-top tube for microbiology and what is its function?

Sodium Polyanethol Sulfonate (SPS); it prevents clotting and preserves microorganisms.

What is the required blood-to-citrate ratio for a Light Blue-top tube?

$9:1$.

What additive is found in a Lavender-top tube used for CBC?

EDTA (Ethylenediaminetetraacetic Acid), specifically $K_{2}EDTA$ or $K_{3}EDTA$.

What color tube is used for glucose testing and what are its additives?

Gray-top tube; contains Potassium Oxalate (anticoagulant) and Sodium Fluoride (antiglycolytic agent).

Why is the Orange-top tube drawn last in the order of draw?

Because it contains thrombin, a strong clotting agent that could contaminate other tubes if carried over.

How many inversions are required for a Light Blue-top tube?

$3-4\text{ inversions}$.

Which tube color is used for Heparin additives and what is Heparin's mechanism?

Green-top tube; it inhibits the conversion of prothrombin to thrombin.

What is the most critical first step in blood collection?

Patient identification.

What are the most common identifiers to verify for a patient?

The patient’s complete name and date of birth.

Why should you never 'pre-label' tubes before blood collection?

To avoid misidentification errors, such as using a pre-labeled tube for the wrong patient if the original patient becomes unavailable.

What is 'hemoconcentration' and how do you avoid it during venipuncture?

The alteration of test results; avoid it by not allowing the patient to continuously clench or pump their fist.

What direction should the needle bevel face during insertion?

Bevel facing UP.

What is the purpose of 'priming' a syringe?

Pushing and pulling the plunger to ensure it is moving smoothly before starting the draw.

Define 'fomites' in terms of infection transmission.

Contaminated equipment or medication (such as multidose vials) that facilitate indirect transmission.

How long should handwashing be performed when hands are soiled?

$1\text{ to }2\text{ minutes}$.

What are the common tests performed using a Lavender-top tube?

CBC (Complete blood count), blood typing, HbA1c, and ESR (Erythrocyte Sedimentation Rate).

Which additive is used to preserve glucose for up to 24 hours?

Iodoacetate.

In which tube is Sodium Citrate the anticoagulant?

Light Blue-top tube.

Why is the median cubital vein the 'safest' site for venipuncture?

It is well-anchored and away from major nerves and arteries compared to the basilic vein.

What is the recommended motion for cleaning the venipuncture site with an antiseptic?

Up (^) and Down (v) motions.

How long must the phlebotomist wait for the antiseptic to dry?

$30\text{ to }60\text{ seconds}$.

What information must be included on the label of a blood sample?

Patient’s full name, date of birth, date of extraction, time of extraction, and phlebotomist’s initials.

What is the purpose of the 'flange' on a syringe barrel?

To allow for secure handling and prevent slipping during use.

When using a butterfly set, what is the 'wing' used for?

Holding the needle during insertion and securing the apparatus.

According to the transcript, what should a phlebotomist strive for?

'The skill of a surgeon and the sympathy of a saint'.