Clinical Chemistry Final Review

The Occupational Safety and Health Administration (OSHA) provides

a. Guidelines for writing procedure manuals

b. Safe environments for patients

c. Specimen collection guidelines

d. Criteria for disposal of chemical waste

b. Safe environments for patients

Universal Precautions states that blood and body fluids should be considered a biohazard

a. At all times

b. When it comes from a hepatitis patient

c. If the color is green or yellow

d. Never

a. At all times

Hand-to-mouth contact is a hazard in the laboratory. Of the following situations, the one that is not hand-to-mouth contact is

a. Chewing on a pencil eraser

b. Pipetting without a suction device

c. Not wearing a face shield

d. Wiping your face with a laboratory coat sleeve

c. Not wearing a face shield

Class A fire extinguishers may be used to put out a fire where the burning substance is

a. A window shade

b. Paint thinner

c. A computer terminal

d. An oscillating fan

a. A window shade

Special collection requirements for specimens may be found in the

a. Collection tray

b. Fire and safety manual

c. OSHA regulations

d. Specimens collection manual

d. Specimen collection manual

Of the following tests, the one performed in Special Chemistry is

a. Electrolytes

b. Drug screen

c. Glucose

d. Protein

b. Drug screen

A test profile is

a. Single test which diagnoses a clinical condition

b. Special chemistry test which requires special instrumentation

c. Group of tests arranged by the organ which is being analyzed

d. Set of criteria for performing a specific test

c. Group of tests arranged by the organ which is being analyzed

Of the following substances, which would not be covered under the concept of Universal Precautions?

a. Chemicals

b. Serum samples

c. Urine

d. Spinal fluid

a. Chemicals

Removal of gloves should take place when

a. The gloves are soiled

b. Leaving the laboratory

c. Shaking hands with the sales representative

d. All of the above

d. All of the above

Biohazardous spills are cleaned by

a. Wiping with a paper towel

b. Diluting with soap and water

c. Decontaminating with sodium hypochlorite (NaCLO)

d. Calling the housekeeping department

c. Decontaminating with sodium hypochlorite (NaCLO)

A pipet that has an etched ring near the mouth end should be

a. Rinsed after delivery of the liquid

b. Be allowed to freely drain

c. Blown out

d. Used for critical measurements

c. Blown out

A flat-bottom flask with sloping sides and a neck that resembles a bottle is a

a. Griffin beaker

b. Erlenmeyer flask

c. Florence flask

d. Graduated cylinder

b. Erlenmeyer flask

A pipet marked with a TD should be

a. Rinsed after delivery of the liquid

b. Allowed to freely drain

c. Blown out

d. used for critical measurements

b. Allowed to freely drain

To make critical dilutions and measurements, one should use a

a. Beaker

b. Volumetric flask

c. Florence flask

d. Graduated cylinder

b. Volumetric flask

A standard curve for glucose is prepared using 3 standards of varying concentrations. Some unknown patient samples are analyzed. The concentration of the patient samples may be determined by

a. Choosing a value which is close to one of the standards

b. Evaluating one additional standard with these patient

c. Reading the patient values from the standard curve

d. Averaging the patient sample results with those from the standards

c. Reading the patient values from the standard curve

When using a volumetric pipet, a drop remains. The technician should

a. Blow out the remaining drop

b. Touch the tip to the side of the tube

c. Rinse the pipet

d. Do nothing

b. Touch the tip to the side of the tube

When making a dilution in a volumetric flask, the technician adds water until it is above the fill line. The technician should

a. Remove the excess water with a pipet

b. add more water to bring the level to the top of the flask

c. Mix the flask and then remove a small amount of water

d. Begin preparing the solution again

d. Begin preparing the solution again

The system that includes standards of quality for all stages of the analytical process is called

a. Quality insurance

b. Controls

c. Quality assurance

d. Standardization

c. Quality assurance

*Double check answer*

The part of quality assurance system that involves the analyses done in the laboratory is

a. The pre-analytical stage

b. The analytical stage

c. The post-analytical phase

d. External quality control

b. The analytical stage

Quality control that involves control specimens coming to a laboratory from an outside source and being evaluated by an outside agency is called

a. External quality control

b. Internal quality control

c. Pre-analytical phase

d. Post-analytical phase

a. External quality control

Reference ranges are usually established on a population of

a. Healthy people

b. Unhealthy people

c. A mixture of healthy, and unhealthy people

d. Geriatric people

a. Healthy people

On a Levy-Jennings chart. the center line is given a designation of the

a. Coefficient of variation

b. Mean

c. Standard deviation

d. Variance

b. Mean

Acceptable range is commonly defined as the

a. Mean plus or minus 2%

b. Mean plus 1 standard deviation

c. Mean plus the variance squared

d. Mean plus or minus 2 standard deviations

d. Mean plus or minus 2 standard deviations

Which of the following is included in the post-analytical phase

a. Commercial controls

b. Reporting results

c. Manual test methods

d. Specimen collection

b. Reporting results

The mean value is also known as the

a. Average

b. Coefficient of variation

c. Standard deviation

d. Variance

a. Average

The spectrophotometer makes its measurements based on the principle of light

a. Transmittance

b. Scatter

c. Color

d. Wavelength

A. Transmittance

The spectrophotometer's light path is determined by the size of the

a. Bulb

b. Photodetector

c. Cuvette

d. Monochromator

c. Cuvette

When light passes through a solution in a cuvette, the measurement that is actually registered on the photodetector is light which was

a. Absorbed by the solution

b. Transmitted through the solution

c. All the light from the tungsten lamp

d. Reflected from the monochromator

b. Transmitted through the solution

Cuvette matching is vital to accurate measurements because mismatches cuvettes

a. Can lead to errors in colorimetry

b. Will be difficult to use

c. Will not fit into the sample well properly

d. Will not have etched markings on them

a. Can lead to errors in colorimetry

Many chemical reactions require that an instrument maintain a specified incubation temperature. How frequently should the accuracy if the thermometer used to monitor the incubation temperature be verified?

a. Daily

b. Monthly

c. Weekly

d. Biannually

d. Biannually

Checking instrument calibration, temperature accuracy, and electronic parameters are part of

a. Preventative maintenance

b. Quality control

c. Function verification

d. Precision verification

a. Preventative maintenance

For which of the following laboratory instruments should preventive maintenance procedures be performed and recorded?

a. Analytical balances

b. Centrifuge

c. Chemistry analyzers

d. All of the above

d. All of the above

What term applies to the sum of all the values in a set of numbers divided by the number of values in that set?

a. Median

b. Mode

c. Arithmetic mean

d. Geometric mean

c. Arithmetic mean

What assistance does an external quality assurance program provide for a laboratory?

a. Means to correlate tests performed by different departments within the same laboratory

b. Delta checks was previous tests on the same patient

c. Evaluation of its performance by comparison with other laboratories using the same method

d. Limits for reference intervals

c. Evaluation of its performance by comparison with other laboratories using the same method

What percentage of values will fall between +/- 2s in a Gaussian (normal) distribution?

a. 34.13%

b. 68.26%

c. 95.45%

d. 99.74%

c. 95.45%

which of the following is material of known composition available in a highly purified form?

a. Standard

b. Control

c. Technical reagent

d. Test analyte

a. Standard

In spectrophotometric analysis, what is the purpose of the reagent blank?

a. Correct for interfering chromogens

b. Correct for lipemia

c. Correct for protein

d. Correct for color contribution

d. Correct for color contribution of the reagents

Which of the following formulas is an expression of the Beer-Lambert law that is routinely applied to spectrophotometric analysis?

a. Au/As × Cs = Cu

b. Cu × Cs/As = Au

c. As × Cs/Cu = Au

d. A = 2 - log %T

a. Au/As × Cs = Cu

In spectrophotometry, which of the following is a mathematical expression of the relationship between absorbance and transmittance?

a. A = abc

b. a = 2 - log %T

c. a= log %T

d. Au/Cu = As/Cs

b. a = 2 - log %T

What term describes the extent of agreement between repeated analysis

a. Random error

b. Precision

c. Accuracy

d. Reliability

b. Precision

What is the following formula used to calculate?

a. Coefficient of variation

b. Variance

c. Confidence limits

d. Standard deviation

d. Standard deviation

Calculate the coefficient of variation (percent) for a set of data where the mean (x bar) = 89mg/dL and 2 standard deviations (s) = 14 mg/dL

a. 7.8

b. 7.9

c. 15.7

d. 15.8

b. 7.9

CV = (s/(x bar[mean])) x 100

CV = (7/89) x 100

CV = 7.865168539

CV = 7.9

Gaussian distribution

Normal distribution. A population of data that has a tendency to cluster symmetrically.

Shift

An abrupt and sustained change (in one direction) in control values.

Mean

Arithmetic average of a set of data

Trend

A gradual change in the test results obtained from control material that is suggestive of a progressive problem with the testing system or control material; also called drift.

Levy-Jennings plot

A visual tool for evaluating quality control data in the context of previous QC results where data are plotted relative to the mean +/- 2 SD on the vertical (y) axis versus days on the horizontal (x) axis.

Standard Deviation (SD)

Square root of a variance.

CV

Coefficient of variation. A relative standard deviation in which the standard deviation is divided by the mean and multiplied by 100%.

Class A

Ordinary combustible solid materials

Class B

Flammable liquids/gases/petroleum products

Class C

Energized electrical equipment

Class D

Combustible/reactive metals

Match the class of fire with the type of extinguisher:

Class A

Pressurized water, ABC (dry chemical)

Match the class of fire with the type of extinguisher:

Class B

ABC (dry chemical), BC (CO2)

Match the class of fire with the type of extinguisher:

Class C

BC (CO2), Halon, ABC (dry chemical)

Match the class of fire with the type of extinguisher:

Class D

Metal X

The NFPA developed a standard hazard ID system (diamond shaped, color coded). Match the color with the type of hazard.

Blue quadrant

Health hazard

The NFPA developed a standard hazard ID system (diamond shaped, color coded). Match the color with the type of hazard.

Red quadrant

Flammable hazard

The NFPA developed a standard hazard ID system (diamond shaped, color coded). Match the color with the type of hazard.

Yellow quadrant

Reactivity/stability hazard

The NFPA developed a standard hazard ID system (diamond shaped, color coded). Match the color with the type of hazard.

White quadrant

Other special information

A trend in QC results is most likely caused by

a. Deterioration of the reagent

b. Miscalibration of the instrument

c. Improper dilution of standards

d. Electronic noise

a. Deterioration of the reagent

The term R4s means that:

a. Four consecutive controls are greater than +/- 1 standard deviation from the mean

b. Two consecutive controls in the same run are greater than 4 standard deviation units apart

c. There is a shift above the mean for four consecutive controls

d. Two consecutive controls in the same run are greater than +/- standard deviations from the mean

b. Two consecutive controls in the same run are greater than 4 standard deviation units apart

One of the two controls within a run is above +2 standard deviations and the other control is below -2 standard deviations from the mean. What do these results indicate?

a. Poor precision has led to random error (RE)

b. A systematic error (SE) is present

c. Proportional error is present

d. QC material is contaminated

** Check answer w/ classmates

When referring to quality control (QC) results, what parameter usually determines the acceptable range?

a. The 95% confidence interval for the mean

b. The range that includes 50% of the results

c. The central 68% of results

d. The range encompassed by +/- 2.5 standard deviations

a. The 95% confidence interval for the mean

Which of the following conditions is cause for rejecting and analytical run?

a. Two consecutive controls greater than 2 standard deviations above or below the mean

b. Three consecutive controls greater than 1 standard deviation above the mean

c. Four controls steadily increasing in value but less than +/- 1 standard deviation from the mean

d. One control above +1 standard deviation

a. Two consecutive controls greater than 2 standard deviations above or below the mean

Which of the following quality control (QC) rules would be broken 1 out of 20 times by chance alone?

a. 1 2s

b. 2 2s

c. 1 3s

d. 1 4s

a. 1 2s

Which of the following assays has the poorest precision? (Calculate CV to do this)

a. Analyte: Ca, Mean(mmol/L): 2.5. Standard Deviation: 0.3

b. Analyte: K, Mean(mmol/L) 4.0 Standard Deviation: 0.4

c. Analyte: Na, Mean(mmol/L) 140 Standard Deviation: 4.0

d. Analyte: Cl, Mean(mmol/L) 100 Standard Deviation: 2.5

a. Analyte: Ca, Mean(mmol/L): 2.5. Standard Deviation: 0.3

CV = (s/(x bar[mean])) x 100

(0.3/2.5) x 100 = 12

Which of the following plots is best for detecting all types of QC errors?

a. Levy-Jennings

b. Tonks-Youden

c. Cusum

d. Linear regression

a. Levy-Jennings

A group of physicians consistently complains that they are not receiving STAT patient results quickly enough. The supervisor is likely to refer to which quality assurance variable?

a. Specimen separation and aliquoting

b. Test utilization

c. Analytical methodology

d. Turnaround time

d. Turnaround time

John Smithers (21 years of age) is in to see his physician for a pre-college physical and checkup. john has always been extremely healthy. The following laboratory results were received.

Astandard = 0.679 Acontrol = 0.650

Asmithers = 0.729 Cstandard = 200 mg/dl

Control Range 190-195 mg/dl

Johns cholesterol concentration is approximately:

a. 186 mg/dl

b. 199 md/dl

c. 209 mg/dl

d. 215 mg/dl

d. 215 mg/dl

25℃ is equivalent to how many degrees Fahrenehit?

a. 31.7°

b. 45.9°

c. 77°

d. 102.6°

c. 77°

How would you prepare a 1/5 dilution of a urine sample?

a. 1 part urine + 3 parts diluent

b. 1 part urine + 4 parts diluent

c. 1 part urine + 5 parts diluent

d. 1 part urine + 6 parts diluent

b. 1 part urine + 4 parts diluent

In the calculation of the mean, what does "n" represent?

a. The sum of the values

b. The number of the values in the set

c. The average of the values

d. The middle number of the set

b. The number of values in the set

Which of the following statistics is equivalent to the square root of the variance?

a. Coefficient of variation

b. Standard deviation

c. Sensitivity

d. Specificity

b. Standard deviation

Use the data to answer question

Cholesterol results for 10 patients

180,200,150,170,150,165,205,150,168,145

Using the data, what is the mean of the cholesterol results?

a. 150

b. 168

c. 187

d. 189

b. 168

Use the data to answer question

Cholesterol results for 10 patients

180,200,150,170,150,165,205,150,168,145

Using the data. what is the mode of the cholesterol?

a. 150

b. 165

c. 168

d. 187

a. 150

Use the data to answer question

Cholesterol results for 10 patients

180,200,150,170,150,165,205,150,168,145

Using the data, what is the standard deviation of the cholesterol results?

a. 13.8

b. 15.1

c. 21.2

d. 26.1

c. 21.2

Which of the following is correct when rounding 2.25 to one decimal place?

a. 2.2

b. 2.3

b. 2.3

What is the sum of the following figures: 0.125 + 3.45 + 32.981

a. 36.556

b. 36.55

c. 36.56

d. 36.6

c. 36.56

The closeness of a test value to the actual value describes which of the following?

a. Accuracy

b. Precision

c. Reproducibility

d. Reliability

a. Accuracy

Which of the Westgard rules is violated in the control data below

GO BACK TO THIS PAT IT NEEDS A PICTURE !!!!!!!-maggie ;) <3

Universal Precautions states that blood and body fluids should be considered a biohazard

a. At all times

b. When it comes from a hepatitis patient

c. If the color is yellow or green

d. Never

a. at all times

Special collection requirements for specimens may be found in the

a. collection tray

b. fire and safety manual

c. OSHA regulations

d. specimen collection manual

d. specimen collection manual

A test profile is

a. single test which diagnoses a clinical condition

b. special chemistry test which requires special instrumentation

c. group of tests arranged by the organ which is being analyzed

d. set of criteria for performing a specific test

c. group of tests arranged by the organ which is being analyzed

Of the following substances, which would not be covered under the concept of Universal Precautions?

a. chemicals

b. serum samples

c. urine

d. spinal fluid

a. chemicals

Removal of gloves should take place when

a. the gloves are soiled

b. leaving the laboratory

c. shaking hands with a sales representative

d. all of the above

d. all of the above

Biohazardous spills are cleaned by

a. wiping with a paper towel

b. diluting with soap and water

c. decontaminating with sodium hypochlorite

d. calling the housekeeping department

c. decontaminating with sodium hypochlorite

To make critical dilutions and measurements, one should use a

a. beaker

b. volumetric flask

c. Florence flask

d. graduated cylinder

b. volumetric flask

A standard curve for glucose is prepared using 3 standards of varying concentrations. Some unknown patient samples are analyzed. The concentration of the patient samples may be determined by

a. choosing a value which is close to one of the standard

b. evaluating one additional standard with these patients

c. reading the patient values from the standard curve

d. averaging the patient sample results with those form the standards

c. reading the patient values from the standard curve

When making a dilution in a volumetric flask, the technician adds water until it is above the fill line. The technician should

a. remove the excess water with a pipet

b. add more water to bring the level to the top of the flask

c. mix the flask and then remove a small amount of water

d. begin preparing the solution again

d. begin preparing the solution again

The system that includes standards of quality for all stages of the analytical process is called

a. quality insurance

b. controls

c. quality assurance

d. standardization

c. quality assurance

the part of the quality assurance system that involves the analyses done in the laboratory is

a. the pre-analytical stage

b. the analytical stage

b. the post-analytical stage

d. external quality control

b. the analytical stage

Quality control involves control specimens coming to a laboratory from an outside source and being evaluated by an outside agency is called

a. external quality control

b. internal quality control

c. pre-analytical phase

d. post-analytical phase

a. external quality control

References ranges are usually established on a population of

a. healthy people

b. unhealthy people

c. a mixture of healthy and unhealthy people

d. geriatric people

a. healthy people

On a levy-Jennings chart, the center line is given a designation of the

a. coefficient of variation

b. mean

c. standard deviation

d. variance

b. mean

Acceptable range is commonly defines as the

a. mean plus or minus 2%

b. mean plus 1 standard deviation

c. mean plus the variance squared

d. mean plus or minus 2 standard deviations

d. mean plus or minus 2 standard deviations

which of the following is included in the post-analytical phase

a. commercial controls

b. reporting results

c. manual test methods

d. specimen collection

b. reporting results

The mean value is also known as the

a. average

b. coefficient of variation

c. standard deviation

d. variance

a. average

The spectrophotometer makes its measurements based on the principle of light

a. Transmittance

b. Scatter

c. Color

d. Wavelength

a. transmittance