Clinical Chemistry 1 - PRELIM

Occupational Safety and Health Administration

OSHA Meaning

91-596

OSH Act Public Law #

1970

OSH Act enacted by US Congress in what year?

True

True or False: Safety is not a moral obligation but a federal law.

Code of Federal Regulations

CFR Meaning

Blood-borne Pathogen Standard

• It defines terminology relevant to blood exposures and mandates the development of an exposure control plan

• The standard precautions concept (formerly referred to as universal precautions)

29 CFR 1910.1030

Blood-borne Pathogen Standard CFR?

Hazard Communication Standard

• To ensure that the hazards of all the chemicals used in the workplace have been evaluated and that this hazard information is successfully transmitted to employers and their employees who use the substances

• Informally referred to as the OSHA “HazCom Standard”

• Safety data Sheets (SDSs)

29 CFR 1910.1200

Hazard Communication Standard CFR?

Occupational Exposure to Hazardous Chemicals in Laboratories

• To address the shortcomings of the Hazard Communication Standard regarding its application peculiar to the handling of hazardous chemicals in laboratories

• The Laboratory Standard requires the appointment of a chemical hygiene officer and the development of a chemical hygiene plan to reduce or eliminate occupational exposure to hazardous chemicals

29 CFR 1910.1450

Occupational Exposure to Hazardous Chemicals in Laboratories / Lab Standard CFR #?

Fume hood

• This lab equipment is required to contain and expel noxious and hazardous fumes from chemical reagents.

• This should be visually inspected for blockages.

• Inspected (QC) at least once a year.

BSC Class I

• The most basic biosafety cabinet.

• Open front; unsterilized room air passes through HEPA before being exhausted.

• Typically used to enclose centrifuges or for aerating cultures that might generate aerosols.

• Provides personnel and environmental protection but NO sample/product protection.

ducted, unducted

Two types of Class I BSCs:

ducted

Type of Class I BSC that is connected to the building exhaust system

unducted

Type of Class I BSC that recirculates filtered exhaust back into the laboratory

BSC Class II

• Biosafety cabinet that provides worker, environmental, and product protection from exposure to potential infectious material.

Class IIA

BSC Class II that:

• Recirculates 70%

• Exhausts 30% of HEPA-filtered air either back into the room or to the outside through a canopy unit

Class IIB

BSC Class II that:

• Recirculates 30%

• Exhausts 70% of HEPA-filtered air to the outside through a dedicated duct

BSC Class III

• Also known as “glove boxes.”

• A totally enclosed, ventilated cabinet.

• Lab workers manipulate items in the cabinet through attached rubber gloves that are accessible from outside.

• Two HEPA filters arranged in a series, or HEPA filters in combination with incineration.

BSC Class III

BSC Class that provides maximum protection to the operator, environment, and sample against high-risk group 4 pathogenic organisms.

gown, mask, goggles, gloves

Sequence of donning

gloves, goggles, gown, mask

Sequence of doffing

Explosion-proof refrigerator

This is where flammable materials should be stored.

biosafety

CDC defines this as:

• An application of safety precautions that reduce laboratorians’ risk of exposure to a potentially infectious material, limit contamination of the work environment, and ultimately, the community.

• Safety from exposure to infectious agents.

acute toxicity

Hazard: skull and crossbones means?

aquatic toxicity

Hazard: tree/environment means?

oxidizers

Hazard: flame over circle means?

explosives

Hazard: exploding bomb means?

corrosive to skin and/or metals

Hazard: Corrosion/chemical means?

gases under pressure

Hazard: gas cylinder means?

irritant or sensitizer

Hazard: exclamation mark means?

flammable

Hazard: flame means?

carcinogen or mutagenicity

Hazard: health hazard means?

heat, oxygen, fuel

Three components needed by fire:

Class A

Fire classification: ordinary combustible solid materials (paper, wood, plastic, fabric)

Class B

Fire classification: flammable liquids/gases and combustible petroleum products

Class C

Fire classification: energized electrical equipment

Class D

Fire classification: combustible/reactive metals (magnesium, sodium, potassium)

pull, aim, squeeze, sweep

PASS meaning (use of fire extinguisher)

Celsius or centigrade

Predominant temperature measurement uses what scale?

Kelvin

SI designation for temperature

C(9/5) + 32

Celsius to Fahrenheit formula

(F - 32) 5/9

Fahrenheit to Celsius formula

thermistor

Clinical laboratory thermometer that is now seldomly used

to deliver, to contain

Types of pipettes according to design

transfer liquids

Purpose of pipettes

blowout, self-draining

Pipette drainage characteristics (2)

distilled water

What to use when calibrating ‘to deliver’ pipettes?

mercury

What to use when calibrating ‘to contain’ pipettes?

automated pipette

• The most routinely used pipette in today’s clinchem laboratory.

fixed volume, variable

Other names/types of automated pipettes (2)

1 uL to 1000 uL

Liquid capacity of automated pipettes (range)

desiccants and desiccators

• Designed to absorb water vapor from reactants that are hygroscopic.

• Also known as ‘drying agents.’

• Anhydrous (containing no water), hygroscopic (tending to absorb moisture from the air.)

balance

• Used to make high-quality reagents.

• Used in preparation for standards.

• Not commonly used nowadays.

• Mechanical or electronic types.

centrifugal force

Principle of the centrifuge

centrifugation

• The process in which centrifugal force is used to separate serum or plasma from the blood cells as blood samples are processed.

• Separates phases of suspensions by different densities.

• Separates supernatant from precipitate during an analytic reaction.

mass, speed, radius

Three variables of centrifugal force:

revolutions per minute (RPM)

Centrifuge speed is expressed as?

relative centrifugal force (RCF) or gravities (g)

Centrifugal force is expressed as? (2)

screening or case finding, diagnosis of disease, therapeutic monitoring

Purposes of the test request (3)

creatine kinase, aspartate aminotransferase, lactate dehydrogenase, aldolase

analytes that increase in the long-term due to exercise (4)

potassium, phosphate, lactate

analytes that increase with vigorous hand exercises/fist clenching within 10 seconds (3)

6 to 10 hours

FBS fasting requirement (range)?

8 hours

FBS fasting requirement (average)?

10 to 14 hours

Lipid Profile fasting requirement (range)?

12 hours

Lipid Profile fasting requirement (average)?

10 hours

Testing for both FBS and Lipid Profile, fasting requirement?

24 hours

Changes in diet, drinking of alcohol, and excessive exercise must be avoided for at least how long before blood collection?

15 to 20 minutes

Patients must be seated/supine for at least how long before blood collection?

30 minutes

prolonged standing for how long would increase potassium levels significantly?

5 minutes

When testing for lipids, patients must be seated for at least how long before extraction?

plasma albumin

This analyte is decreased in patients under prolonged bed rest.

hemoconcentration

Tourniquet application longer than 1 minute leads to?

longer than 1 minute

Hemoconcentration results from tourniquet application that lasts?

potassium, proteins (albumin), enzymes, cholesterol, ammonia

Hemoconcentration resulting from tourniquet application longer than 1 minute leads to falsely increased levels of which analytes? (5)

10 to 15%

Hemoconcentration resulting from tourniquet application longer than 1 minute leads to total cholesterol that is falsely increased by how much? (range)

catecholamines, carboxyhemoglobin, cholesterol, triglycerides

Falsely elevated analytes from acute effects of tobacco smoking (4)

lactate, epinephrine, hemoglobin concentration, RBC and WBC count, MCV (mean cell/corpuscular volume)

Falsely elevated analytes from chronic effects of tobacco smoking (5)

glucose

Diabetic patients with chronic alcoholism have falsely lowered levels of which analyte?

decreased HDL, elevated gamma-glutamyl transferase (GGT), and elevated MCV

The false chronic effects of alcohol ingestion are: (3)

catecholamines

The analytes that are the first responders to stress

cortisol

The analyte that is the primary stress hormone

catecholamines, cortisol, ACTH, prolactin, glucose, lactate

Stress elevates which analytes? (6)

total cholesterol

Mild stress causes a slight increase in?

15%

Mild stress causes a decrease in HDL by almost how much?

liver function enzymes

Hepatotoxic drugs increase which analytes?

sodium and potassium / Na and K

Diuretics can decrease which analytes?

vitamin C

This can cause positive or negative reactions in many analytes.

4 to 6 AM

Cortisol peaks at what time range?

8 PM to 12 AM

Cortisol is lowest at what time range?

ACTH, plasma renin, aldosterone, insulin

Analytes that are lower at night (4)

early to late morning

Serum iron peaks when?

30%

Serum iron decreases by how much throughout the day?

morning / AM

Neutrophil count is lowered in the?

night / PM

Neutrophil count is elevated in the?

venipuncture, arterial puncture, skin/capillary puncture

General methods for blood collection (3)

30 minutes

Red top tube has to stand for how long?

5 minutes

Gold top tube has to stand for how long?

Accuvein (vein viewer)

• This is a handheld medical device that helps visualize veins before phlebotomy.

• Used for the elderly, obese, burn victims, and those with chronic diseases.