Clinical Chemistry Flashcards
(483 cards)
1
Q
Act of obtaining a blood sample from a vein using a needle attached to a syringe or a stoppered evacuated tube;
The most common way to collect blood specimens
A
Venipuncture
2
Q
Major veins for venipuncture
A
- Median cubital vein
- Cephalic vein
- Basilic vein
3
Q
Most common site for venipuncture
A
antecubital fossa
4
Q
The ___ pattern is displayed by approximately 70% of the population
A
H pattern
5
Q
vein located near the center of the antecubital fossa;
Preferred vein - large and closer to the surface, the most stationary
Easiest and least painful to puncture
Least likely to bruise
A
Median cubital vein
6
Q
Second choice vein;
Harder to palate than median cubital vein
Fairly well-anchored;
often the only vein felt in obese patients
A
Cephalic vein
7
Q
Last choice of vein
Not well anchored and rolls easily
Increased risk of puncturing a median cutaneous nerve branch or the brachial artery
not recommended unless no other vein in either arm is more prominent
A
Basilic vein
8
Q
Veins on the back of the hand and wrist may also be used for venipuncture
A
True
9
Q
Veins on the underside of the wrist should never be used for venipuncture
A
True
10
Q
Leg, ankle and foot veins are sometimes used but not without permission of the patient’s physician, due to potential for significant medical complications
A
True
11
Q
3 Types of Blood specimens
A
- Serum
- Plasma
- Whole blood
12
Q
Not normally a clear, pale yellow fluid;
Separated from clotted blood by centrifugation
Many chemistry tests are performed using this specimen
A
Serum
13
Q
Non fasting serum can be cloudy due to ____
A
lipids
14
Q
Normal clotting time for serum
A
30 mins
15
Q
Does serum contain fibrinogen and other coagulation factors?
A
No
16
Q
Centrifugation speed and time to obtain serum specimen
A
10 minutes at an RCF of 1,000 to 2,000 g
17
Q
Normally a clear to slightly hazy, pale yellow fluid;
Separates from the cells when blood in an anticoagulant tube is centrifuge;
Contains fibrinogen
A
Plasma
18
Q
Is fibrinogen present in the plasma
A
Yes
19
Q
Fibrinogen is not present in the serum because ___
A
It was used in clot formation
20
Q
Stat and other tests requiring a fast Tat are often collected in tubes containing ___ anticoagulant because they can be centrifuged immediately to obtain plasma
A
Heparin
21
Q
contains both cells and plasma;
Must be collected in an anticoagulant tube to keep it from clotting;
used for most hematology tests and many POCTs, especially in acute care and Stat situations
A
Whole blood
22
Q
3 Methods of venipuncture
A
- ETS
- Needle and syringe
- Butterfly set
23
Q
Preferred method of venipuncture because blood is collected from the vein into the tube, minimizing the risk of specimen contamination and exposure to the blood
A
ETS
24
Q
discouraged by CLSI due to safety and specimen quality issues; sometimes used on small, fragile or damaged veins
A
Needle and syringe
25
Can be used with ETS or a syringe; often used to draw blood from infants and children, hand veins, Difficult-draw situations.
Butterfly set
26
Restrict venous flow but not arterial flow
Tourniquet
27
Tourniquets must not be left on longer than
1 minute
28
Length and width of the tourniquet
1 inch wide x 15 inches long
29
Gauge and bore are inversely related
True
30
Gauge considered standard for routine venipuncture
21 gauge
31
Gauge used for pediatrics
23 gauge
32
3 basic components of the ETS
Multisample needle, tube holder, evacuated tubes
33
Includes a plastic syringe, a needle, and a transfer device
Syringe system
34
23 gauge most commonly used for phlebotomy
Butterfly system
35
Handheld medical device that helps medical staff visualize veins before phlebotomy.
AccuVein
36
AccuVein emits ___ and is held about 7 inches over the potential phlebotomy site
infrared light
37
Tube color without an anticoagulant or additive (Glass itself can activate clotting)
Red
38
Activates intrinsic pathway
Negatively charged surface
Negatively = iNtrinsic
39
Extrinsic pathway is activated by
Tissue factor
"Ng dahil Kay EX, kinailangan mo ng TISSUE"
40
Type of EDTA tube that can shrink RBCs to (Low HCT, Low MCV) , but it can be used for PBS
K3EDTA (liquid form)
41
More preferred in routine CBC
K2EDTA
42
Tube color and anticoagulant/additive used for whole blood/ blood bank and molecular diagnostics
Pink (Pray-dried K2EDTA)
43
Tube color and anticoagulant/additive used for molecular diagnostics
White (EDTA and gel)
44
Blood to anticoagulant ratio for light blue (sodium citrate)
9:1
45
More preferred Na citrate concentrations
3.2%
46
Tube and anticoagulant used for sedimentation rate
Black (sodium citrate)
47
Blood to anticoagulant ratio for ESR
4:1
48
Alternative top for ESR
Lavender
49
Intravenous anticoagulant ;
Universal anticoagulant
Heparin
50
Top and anticoagulant used for toxicology
Royal blue (sodium heparin, K2EDTA)
51
Binds magnesium, thus inhibiting the MG-depended enzyme, enolase
Sodium fluoride
52
Antiglycolytic agent in gray top tube
Sodium fluoride
53
Anticoagulant in gray top tube
Potassium oxalate
54
Sterile containing sodium polyanetholesulfonate; used for microbiology culture
Yellow
55
Top and anticoagulant used blood bank phenotyping and paternity testing
Yellow (acid citrate dextrose)
56
Top and anticoagulant used for lead testing
Tan (sodium heparin)
57
Top used for faster clotting (5-10 minus clotting time); contains thrombin
Yellow/ Gray and orange
58
CLSI Order of Draw
1. Sterile tube
2. Coagulation tube
3. Serum tube with or without clot activator, with or without gel
4. Heparin tube with or without gel separator
5. EDTA tube with or without gel separator
6. Glycolytic inhibitor tube
"Stop, light red! Stay put, Green Light, go!"
59
Preferred specimen for newborn screening tests
Capillary blood
60
Length of lancet to be used for capillary puncture
less than 2.0 mm
61
Sites for capillary puncture
Palmar surface of 3rd and 4th fingers for adults
Lateral plantar heel surface (newborns)
Earlobes (alternative)
62
Capillary order of Draw
1. EDTA specimens
2. Other additive specimens
3. Serum specimens
63
For blood gas analysis and pH measurements
Arterial puncture
64
In arterial puncture, __ are used instead of evacuated tubes because of the pressure in an arterial blood vessel
Syringes
65
Preferred anticoagulant for arterial puncture
Heparin
66
Arterial puncture collects without a tourniquet
True
67
Primary arterial sites (in order of preference)
Radial, brachial, femoral arteries
68
Major complications of arterial puncture
Thrombosis, hemorrhage, and possible infection
69
Done before collecting an arterial blood from Radial artery to determine whether the ulnar artery can provide collateral circulation to the hand after the Radial artery puncture
Modified Allen Test
70
Peaks at 4-6 AM;
lowest at 8 PM - 12 AM;
50% lower at 8PM than at 8 AM
Cortisol
71
Peaks early to late morning; decreased up to 30% during the day
Iron
72
Increased after recent food ingestion
Glucose, insulin, TAG, gastrin, ionized calcium
73
Decreased after recent food ingestion
Chloride, phosphorus, potassium, amylase, ALP
74
T or F
Potassium doesn't increase post prandially, thus it does not require fasting
T
75
Increased when an individual is stressed
ACTH, cortisol, catecholamines, prolactin
76
What is the first to increase during stress?
Catecholamines
77
Array of signs and symptoms resulting from increased cortisol
Cushing's syndrome
78
Elevated ACTH from the pituitary gland resulting to increased cortisol
Cushing disease
79
Require fasting
FBS, GTT, TAG, LP, Gastrin, Insulin, Ald/Renin
80
Require Ice (immediate cooling)
Lactic acid, ammonia, blood gas (if not cooled = decreased pH and pO2)
"LAB ICE"
81
Increased when an hemolysis occurs
Potassium, pO4, Fe, Mg, ALT, AST, LD, ALP, Cathecolamines, CK (marked hemolysis)
82
Ideally, specimens must be delivered to the laboratory within ___ of collection
45 minutes
83
Specimens must be centrifuged within ___ of arrival if serum or plasma is needed
1 hour
84
Maximum time limit for serum or plasma separation is ___ after collection
2 hours
85
Medical term meaning "immediately" (from the Latin "statim")
Stat collections
86
Given the highest priority and are usually ordered from the emergency department and critical care units
Stat collections
87
Analytical patient testing activities provided within the institution, but performed outside the physical facilities of the clinical laboratories
POCT
88
Laboratory testing tat is performed outside the central or core laboratory and generally at the site of clinical care or close to the patient
POCT
89
The highest volume POCT in most health care institutions
POC glucose
90
A drop of blood most frequently obtained via ___ is applied to a test strip
capillary puncture
91
Common POCTs (Tests requiring immediate decisions)
Glucose, blood gases, cardiac markers, urinalysis, creatinine, PT/INR, Infectious diseases (HIV, RSV, influenza), drug screening
92
Most common error in specimen collection
Misidentification of patient
93
Most common reason for specimen rejection
Hemolysis or lipemia
94
Next most common fluid for determination after blood; quantitative analysis require timed samples (usually 24 hours)
Urine
95
assess fetal lung maturity, congenital diseases, hemolytic diseases, genetic defects, gestational age
Amniotic fluid
96
Specifications established by the ACS
Suitable for use in most analytic laboratory procedures
Analytical Reagent
97
Additional purification steps
For use in specific procedures such as chromatography, atomic absorption, immunoassays, molecular diagnostics, standardization or other techniques that require extremely pure chemicals
Ultrapure
98
Used to manufacture drugs; Purity criterion are not based on laboratory needs
United Stated Pharmacopeia / National Formulary
99
Impurity specifications are not stated
Chemically pure or pure grade
100
Used primarily in manufacturing and should never be used in the clinical laboratory
Technical/ Commercial Grade
101
Highly purified chemical that can be measured directly to produce a substance of exact known concentration and purity
Primary standard
102
substance of lower purity with concentration determined by comparison with a primary standard
Secondary standard
103
Type of water purity having the most stringent requirements and generally suitable for routine laboratory use.
Type I water
104
Pipet design that holds or contains a particular volume but does not dispense that exact volume
To contain
105
Pipet design that will dispense the volume indicated
To deliver
106
Continuous etched ring or two small, close continuous rings located near the top of the Pipet
Blowout
107
allows the contents of the Pipet to drain by gravity
Self-draining
108
Measuring or graduated pipets
Serologic
Mohr
Bacteriologic
Ball, Kolmer or Kahn
Micropipet
"SMBBM"
109
Transfer pipets
Volumetric
Ostwald-Folin
Pasteur pipets
Automatic macropipet or micropipet
"VOPA"
110
Graduation marks to the tip; generally a blowout pipet
Serologic
111
No graduations to the tip; self-draining, but the tip should not be allowed to touch the vessel while the Pipet is draining
Mohr
112
Pipet with a total holding of less than 1 ml
Micropipet
113
Dispense or transfer aqueous solutions; self-draining
Volumetric
114
For biologic fluids having a viscosity greater than that of water; blow out
Ostwald-Folin
115
Pipet with no calibration marks
Pasteur Pipets
116
Most routinely used Pipet
Automated macropipet or micropipets
117
2 types of automated pipets
Air-displacement and positive displacement
118
Piston-operated devices. A disposable, onetime use polypropylene tip is attached to the Pipet barrel. The Pipet tip is placed into the liquid to be aspirated and is drawn into and dispensed from this tip
Air-displacement
119
Use a capillary tip that may be siliconized galss, glass, or plastic. this type of Pipet is useful if a Reagent reacts to plastics. Used a Teflon-tipped plunger that fits tightly inside the capillary. The tips are reusable, and carry-over is negligible if the Pipet is properly maintained. Some procedures require a washing or flushing step between samples.
Positive-displacement pipets
120
Used to dispense a particular volume of liquid during titration
Burets
121
Sometimes used to transfer small volumes in blood gas analysis or in separation techniques such as chromatography or electrophoresis
Syringes
122
hygroscopic substances used as excellent drying substances; used to prevent moisture absorption by chemicals, gases, and instrument components
Desiccant
123
Closed, airtight chamber used with Desiccant
Desiccator
124
Required for preparation of primary standards; the mechanical analytic balance is also known as a substitution balance
Analytic balances
125
Single-pan balances that use electromagnetic force to counter balance the weighed samples mass
Electronic balances
126
Allows the tubes to attain a horizontal position when spinning and a vertical position when the head is not moving
Can attain speeds of up to approximately 3000 rpm --> excessive heat buildup due to increased air friction
Horizontal or swinging bucket
127
Having angled compartments for the tubes and allow small particles to sediment more rapidly
Angle is fixed at around 52 degrees
common in the laboratory
Fixed-angle or angle-head
128
High speed centrifuge used to separate layers of different specific gravities
they are commonly used to separate lipoproteins (used in the reference method for lipoproteins quantitation)
Chamber is refrigerated to counter heat produced through friction
Ultra centrifuge
129
Centrifuge calibration is done every
3 months (quarterly)
130
Disinfect centrifuge ____
Weekly
131
Used to check speed of centrifuge
tachometer or strobe light (can also be a timer)
132
Conversion factor for TAG
0.0113
133
Conversion factor for AST
0.0167
134
Conversion factor for Creatinine clearance
0.0167
135
Conversion factor for cholesterol
0.026
136
Conversion factor for cortisol
0.0276
137
Conversion factor for glucose
0.0555
138
Conversion factor for uric acid
0.0595
139
Conversion factor for vitamin B12
0.0738
140
Conversion factor for iron
0.179
141
Conversion factor for calcium
0.25
142
Conversion factor for phosphorus
0.323
143
Conversion factor for BUN
0.357
144
Conversion factor for magnesium
0.5
145
Conversion factor for ammonia
0.587
146
Conversion factor for Bicarbonate
1
147
Conversion factor for chloride
1
148
Conversion factor for lithium
1
149
Conversion factor for osmolality
1
150
Conversion factor for potassium
1
151
Conversion factor for sodium
1
152
Conversion factor for folic acid
2.27
153
Conversion factor for albumin
10
154
Conversion factor for hemoglobin
10
155
Conversion factor for total protein
10
156
Conversion factor for Thyroxine
12.9
157
Conversion factor for bilirubin
17.1
158
Conversion factor for creatinine
88.4
159
Method of determining the concentration of substance in solution by measuring the amount of light absorbed by that solution after appropriate treatment
Spectrophotometry
160
Photons travelling in waves
electromagnetic radiation
161
distance between 2 peaks; inversely related to energy
wavelength
162
distance between peak and trough (height of the wave)
amplitude
163
Visible light falls between
400 nm to 700 nm
164
Range of infrared light
>700 nm
165
Range of UV light
<400 nm
166
Wavelength of red light
around 600 - 700 nm
167
States that the concentration of a substance is directly proportional to the amount of light absorbed or inversely proportional to the logarithm of the transmitted light
Beer-Lambert Law (Beer's Law)
168
Most common source of light for work in the visible and near infrared regions
Incandescent tungsten or tungsten-iodide lamp
169
Light source Most commonly used for UV work
Deuterium - discharge lamp and Mercury-arc lamp
170
Isolates the desired wavelength
Monochromators
171
Most commonly used as monochromators
Diffraction gratings
172
Contains the sample
Sample cell/cuvette
173
Has an advantage over round cuvets in that there is less error from the lens effect, orientation in the spectrophotometer, and refraction
Square sample cell
174
Sample cell used for applications in the visible range
Glass
175
Sample cell used for applications requiring UV radiation
Quartz
176
Used in instruments designed to be extremely sensitive to very low light levels and light flashes of very short duration
Photomultiplier tube
177
Parameters routinely monitored in Spectrophotometry
Wavelength or photometic accuracy, absorbance check, linearity, stray light
178
Photometric accuracy can be assessed easily using ___
special glass-type optical filters
179
Filter that has abroad absorption peak around 600 nm
Didymium glass
180
Filter that has multiple absorption peaks with a sharp peak occurring at 360 nm
Holmium oxide
181
Performed using glass filters or solutions that have known absorbance values for a specific wavelength
Absorbance check
182
The ability of a photometric system to yield a linear relationship between the radiant power incident upon its detection and the concentration
Linearity
183
The linearity of a spectrometer can be determined using __
optical filters or solutions that have known absorbance
184
Any light that impinges upon the detector that does not originate from a polychromatic light source
Stray light
185
Stray light can be evaluated by using
special cut off filters
186
Measures the quantity of light reflected by a liquid sample that has been dispensed onto a grainy or fibrous solid support
Reflectometry
187
Applications of Reflectometry
Urine dipstick analysis,
Dry slide chemical analysis
188
Measurement of concentration is done by detecting the absorption of electromagnetic by atoms rather than molecules. when a ground state atom absorbs light energy, an excited atom is produced. the excited atom then returns to the ground state, emitting light of the same energy as it absorbed
Atomic Absorption Spectrophotometry
189
Components of AAS
Hollow-cathode lamp, Flame, Monochromator
190
Usual light source in AAS
Hollow-cathode lamp
191
Breaks chemical bonds and form free, unexcited atoms; serves as sample cells (instead of a cuvet)
Flame
192
Used to isolate the desired wavelength; also protects photo detector from excessive light emanating from flame emissions
Monochromators
193
Application of AAS
Measurement of unexcited trace metals (calcium and magnesium)
194
Measurement of light emitted by excited atoms
Flame photometry
195
Application of Flame Photometry
Determine the concentration of Na, K, Li
196
Lithium (Flame with characteristic color)
Red
197
Sodium (characteristic color in FP)
Yellow
198
Magnesium characteristic color in FP
Blue
199
Rubidium characteristic color in FP
Red
200
Potassium characteristic color in FP
Violet
201
Measurement of the concentration of solutions that contain fluorescing molecules
Fluorometry
202
Most common light source in fluorometry
Xenon lamp
203
Application of fluorometry
in Drugs
204
Chemical energy generated in a chemiluminiscent reaction produces excited intermediates that decay to a ground state with the emission of photons; no excitation is required unlike in fluorometry
Chemiluminescence
205
made with a Spectrophotometer to determine concentration of particulate matter in sample. The amount of light blocked by a suspension of particles depends not only on concentration but also on size
Turbidimetry
206
Applications of turbidimetry:
Detection of bacterial growth and bacterial culture
Antibiotic sensitivity
Coagulation studies
Protein concentration in CSF and urine
True
207
Light scattered by small particles is measured at an angle to the beam incident to the cuvet. Measure particles that are too large for spectrophotometry, such as antibody-antigen complexes formed in enzyme immunoassays.
Nephelometry
208
Involves measurement of the current or voltage generated by the activity of specific ions.
Electrochemistry
209
Analytic techniques involved in electrochemistry
Potentiometry
Coulometry
Voltammetry
Amperometry
210
Measurement of potential (voltage) between 2 electrodes in a solution to measure analyte concentration
Potentiometry
211
Applications of potentiometry
pH, pCO2, Na, Ca, K, NH4
212
Measurement of the current flow produced by an oxidation-reduction reaction
pO2 (Clark electrode), glucose, peroxidase
213
Electrochemical titration in which the titrant is electrochemical generated
Coulometry
214
Application of coulometry
chloride
215
Potential is applied to an electrochemical cell and the resulting current is measured
Voltammetry
216
Applications of voltammetry
Anodic stripping Voltammetry (for lead and iron)
217
Separation of charged compounds based on their electrical charge
Electrophoresis
218
Most commonly used support medium in electrophoresis
cellulose acetate
219
maintains pH
Buffer
220
Movement of buffer ions and solvent relative to the fixed support
Electroendosmosis
221
Most common and reliable way for quantitation of separated protein fractions
Densitometry
222
Separation of complex mixtures on the basis of different physical attractions between the individual compounds and the stationary phase of the system
Chromatography
223
Components of chromatography
Mobile phase
Stationary phase
Column
Eluate
224
It carries the complex mixture in chromatography
Mobile phase
225
Substance through which the mobile phase flows
Stationary phase
226
Holds the stationary phase
Column
227
separated components in chromatography
Eluate
228
uses pressure for faster separations
High-Performance Liquid Chromatography
229
Separate mixtures of compounds that are volatile or can be made volatile
Gas-Chromatography
230
Sample in a __ is first volatilized and ten ionized to form charged molecular ions and fragments that are separated according to their mass-to-charge ratio
Mass Spectrometry
231
Application:
Allows definitive identification when used on samples eluting from GC or HPLC
Gold standard for drug testing when coupled with GC
Mass Spectrometry
232
Two-step procedure or MALDI-TOF
1. MALDI
2. Time-of-flight (TOF)
233
A laser pulse irradiated the sample, causing desorption and ionization for both the matrix and the sample
MALDI-TOF MS
234
The molecular weight of the proteins acquired by mass Spectrometry is used to determine the identity of the sample and is helpful in determining post translational modifications that may have occurred
MALDI-TOF MS
235
Analysis of biomolecules such as peptides and proteins (application of MALDI-TOF MS
True
236
Three basic approaches with instruments
Continuous flow, centrifugal analysis, and discrete analysis
237
large number of specimens in one run
Batch analysis
238
Analyzer that offers random-access or Stat capabilities
Discrete analyzers
239
Type of analysis which uses air bubbles in the sample and Reagent streams. Air is injected into each stream as a series of small bubbles which travel along with the reaction system. The air bubbles minimize diffusion of reagents and mixing between samples preserving the integrity of each individual reaction
Continuous-Flow Analysis
240
Sample and Reagent are placed in a rotor. When centrifugal force is applied, the rotor spins and causes the two components to flow into a reaction chamber where they combine to form a product.
Centrifugal analysis
241
Slides contain all the materials necessary for a single analysis. No reagents were needed to prepare the slide for use
Dry-slide technology
242
Composition of a dry slide
Spreading layer
Scavenger layer
Reagent layer
Indicator layer
Support layer
243
Point of contact with the sample.
Spreads the sample equally over a defined area. Also serves as a sieve
Spreading layer
244
Optional layer. Removes materials present into the sample which may interfere with the reaction. Example: slide for uric acid containing ascorbate oxidase to remove Vitamin C
Scavenger layer
245
Optional layer. Contains a dye or some other type of indicator which reacts with the products of reaction taking place in the Reagent layer, forming a colored complex
Indicator layer
246
Should be translucent to allow light used in reflectance spectroscopy to pass through
Support layer
247
Light of a selected wavelength shines through the bottom of the cell. the light beam, reflects off the underside of the spreading layer and passes through the Reagent and indicator layers to a photodetector. Any absorbance which takes place must be due to the colored material formed by reactions in the slide
Reflectance Spectroscopy
248
Instrument analysis patient samples only for those constituents specifically ordered and Stat samples can be carried out by momentarily interrupting the normal sequence of patient analyses. The instrument must also be capable of incorporating new tests into the Analytical scheme by addition of appropriate reagents and simple reprogramming for the new test parameters.
Random Access Analysis
249
All samples are loaded at the same time and a single test is conducted on each sample
Batch testing
250
More than one test is analyzed concurrently on a given clinical specimen
Parallel testing
251
Multiple tests analyzed one after the another on a given clinical specimen
Sequential testing
252
Reagents from other manufacturers may be used
Open Reagent system
253
Operator can only use manufacturer's reagents
Closed Reagent system
254
Process by which lab ensures quality results by closely monitoring preanalytical, analytical, and postanalytical stages of testing
Quality assurance
255
Everything that precedes test performance
Preanalytical
256
Everything related to assay
Analytical
257
Everything that comes after test analysis
Postanalytical
258
Comparing results from current to previous
Delta check
259
Part of analytical phase of quality assurance; process of monitoring results from control samples to verify accuracy of patient results
Quality control
260
Controls are run __
Daily
261
Difference between highest and lowest value; easiest measure of spread
Range
262
Most frequently used measure of variation
Standard deviation
263
An index of precision used to compare the dispersion of two or more groups of data with different units or concentrations
Coefficient of variation
264
Used to determine if there is a significant difference between the means of two groups pf data (Compares accuracy)
T- test
ATM
Accuracy
T-test
Mean
265
Used to determine if there is a significant difference between the SD of two groups of data (compares precision)
F-test
SPF
SD
Precision
F-test
266
Describes many continuous laboratory variables and shares several unique characteristics
Gaussian Distribution (Normal Distribution)
267
In the Normal Distribution, the mean , median, mode are identical
True
268
The distribution In the Normal Distribution curve is symmetric (Bell Curve)
True
269
The total area under the Gaussian curve is __
1.0 or 100%
270
The ____ summarizes relations between the area under the Gaussian distribution and the SD
68-95-99 Rule
271
___% of data fall between 1 +/- SD from the mean
68
272
___% of the data fall between +/- 2 SDs from the mean
95
273
__% fall between +/- 3SDs from the mean
99
274
Nearness or closeness of assayed values to the true value
accuracy
275
Nearness or closeness of assayed values to each other
Precision
276
Ability of an analytical method to maintain accuracy and precision over an extended period of time
Reliability
277
degree by which a method can easily be repeated
Practicability
278
ability to measure the smallest concentration of the analyte of interest
Analytical sensitivity
279
ability to measure only the analyte of interest
Analytical specificity
280
Also known as linearity; range of values over which lab can verify accuracy of test system
Reportable range
281
Formerly called normal value / normal range
Can vary for different patient population
Reference interval
282
Reference interval is established by testing minimum of __ healthy subjects and determining range in which 95% fall
120
283
Verifying a reference interval (transference) can require as few as __ study individuals
20
284
Establishing a new reference interval my require from ___ to as many as ___ study individuals
120 - 700
285
Transference and validation of a reference interval requires as few as ___ study individuals
40
286
Reporting a positive result in a patient who has the disease
True Positive
287
Reporting a positive result in a patient who doesn't have the disease
False positive
288
Reporting a negative result in a patient who doesn't have the disease
True negative
289
Reporting a negative result in a patient wo has the disease
False negative
290
% of population with the disease that test positive; ability of the analytical method to detect the proportion of individuals with the disease
Diagnostic sensitivity
291
% of population without the disease that test negative; ability of the analytical method to detect the proportion of individuals without the disease
Diagnostic specificity
292
% of time that a positive result is correct
Positive predictive value
293
% of time that a negative test result is correct
Negative predictive value
294
assayed on a regular schedule to verify that a laboratory procedure is performing correctly
QC samples
295
New instrument or new lot of reagents: analyze QC materials for ___ days
20
296
2 parameters needed for QC
Mean, standard deviation
297
Other name of Levey-Jennings Control Chart
Shewart plot
298
Most common representation for evaluating QC results
Levey-Jennings Control Chart
299
Control values increasing or decreasing for six consecutive runs
Trend
300
Main cause of a trend
Deterioration of reagents
301
six consecutive control values ont he same side of the mean
Shift
302
Main cause of a shift
Improper calibration of the instrument
303
Highly deviating values; control result outside established limits
Outliers
304
Warning rule
1(2S)
305
Present in all measurements; due to chance; no means of predicting it
Random error
306
error that doesn't recur in regular pattern
Random error
307
Associated with violations of the 12s, 13s, and R4s Westgard rules
Random error
308
Error that influences ALL observations consistently in one direction
Systematic error
309
Recurring error inherent in test procedure
Systematic error
310
Associated with violations of the 22s and 41s Westgard rules
Systematic error
311
Error due to dirty glassware
Random error
312
Use of wrong pipet
Random error
313
Voltage fluctuation
Random error
314
Sampling error
Random error
315
Anticoagulant or drug interference
Random error
316
Dirty photometer
Systematic error
317
Faulty ISE
Systematic error
318
Evaporation or contamination of standards or reagents
Systematic error
319
Also known as external quality assessment
Proficiency testing
320
Consists of evaluation of method performance by comparison of results versus those of other laboratories for the same set of samples
Proficiency testing
321
Failed Delta check
> 20% deviation
322
Test results that indicate a potentially life-threatening situation
Critical values
323
critical or panic values for serum glucose
< 40 mg/dL
> 500 mg/dL
324
Approach focusing on process improvement as a means to meet a set standard
Quality management
325
Provides a culture, infrastracture, methodology, and metric for quality improvement
Lean Six Sigma
326
3 Roles of Lean Six Signa team
Black belts (Project coaches/leaders)
Green belts (Project team members)
Blue belts (Project sponsors)
327
full time quality improvement leaders who dedicate 100% of their time to proactively addressing process and quality problems
Project coaches/leaders (Black belts)
328
Contribute 20% of their on project time while maintaining their normal jobs
Project team members (Green Belts)
"20% discount sa Green Belt"
329
Mid-to-senior level sponsors who review the project, remove organizational barriers, and encourage the team members
Project sponsors (Blue belts)
330
Uses a problem-cause-solution methodology to improve any process through waste elimination and variation reduction.
Lean Six Sigma
331
The belief that quality improvement requires sound problem solving
DMAIC Methodology
332
Meaning of DMAIC
Define, Measure, Analyze, Improve, and Control
333
Major energy source; storage form of energy; components of cell membranes; structural component in plants, bacteria, insects
Carbohydrates
334
Where is glycogen stored in the body?
Liver and muscle
335
Bond that links 2 sugar units
Glycosidic bond
336
Breakdown polymers to dextrins and dissacharides
Salivary amylase and pancreatic amylase
337
Glucose + fructose
Sucrose
338
Glucose + galactose
Lactose
339
Glucose + glucose
Maltose
340
____ are absorbed by the gut via active transport (glucose and galactose) or facilitated diffusion (fructose). They are then transported into the liver through the portal circulation
Monosaccharides
341
___ is the only carbohydrate to be used directly for energy
Glucose
342
After glucose enters the cell, it undergoes phosphorylation into glucose-6-phosphate through the action of __ or ___
hexokinase or glucokinase
343
Most common enzyme deficiency in the glycolysis pathway (Embden-Meyerhof pathway)
Pyruvate kinase deficiency
344
Pyruvate kinase deficiency leads to
Hemolytic anemia
345
Marker of hypoxia
Lactate
346
Main purpose of glycolysis
Generates ATP
347
The Hexose-Monophosphate shunt generates ___
NADPH
348
NADPH --> reduced
glutathione
349
Most common enzyme deficiency in the Hexose-Monophosphate shunt
G6PD deficiency
350
Metabolism of glucose molecule to Pyruvate or lactate for production of energy
Glycolysis
351
Formation of glucose-6-phosphate from non-carbohydrate sources
Gluconeogenesis
352
Breakdown of glycogen to glucose for use as energy
Glycogenolysis
353
Conversion of glucose to glycogen for storage
Glycogenesis
354
Conversion of carbohydrates to fatty acids
Lipogenesis
355
Decomposition of fat - ketone production
Lipolysis
356
G6PD leads to
Hemolytic anemia (Heinz bodies)
357
Produced by the beta cells of the islets of Langerhans (pancreas)
Insulin
358
Marker of endogenous insulin production
C-peptide
359
Prepoinsulin --> Proinsulin -->
Insulin
360
Hypoglycemic hormone
Insulin
361
T or F (Physiologic effects of insulin)
Increases utilization of glucose by the cells by increasing cellular uptake and hepatic glycolysis
T
362
T or F (Physiologic effects of insulin)
Increases glycogenesis and inhibits glycogenolysis
T
363
T or F (Physiologic effects of insulin)
Inhibits gluconeogenesis
T
364
T or F (Physiologic effects of insulin)
Stimulates lipogenesis while inhibiting lipolysis
T
365
T or F (Physiologic effects of insulin)
Stimulates protein synthesis and stimulates uptake of amino acids into muscles
T
366
Produced by the alpha cells of the islets of Langerhans
Glucagon
367
BIGADS
Beta cells: Insulin
Glucagon: Alpha cells
Delta cells: Somatostatin
368
T or F (Physiologic effects of glucagon)
Promotes liver glycogenolysis
T
369
T or F (Physiologic effects of glucagon)
Increases glyconeogenesis
T
370
T or F (Physiologic effects of glucagon)
Inhibits glycolysis
T
371
Increases gluconeogenesis; Decreases glucose uptake and utilization by extra hepatic tissues
Cortisol (Glucocorticoids)
372
Stimulates glycogenolysis
Catecholamines
373
Increases glucose absorption in the small intestines
Thyroid hormone
374
Inhibit glucagon and insulin secretion
Somatostatin
375
Increases liver gluconeogenesis; inhibits glycolysis; inhibits glucose transport
Growth hormone
376
Hypercortisolism
Cushing's syndrome
377
Pituitary tumor; Increased ACTH; Increased Cortisol
Cushing's disease
378
Stress hormones (increases in long-term stress)
Cortisol and Catecholamines
379
First to increase during stress
Catecholamines
380
Elevated growth hormone (childhood onset)
Gigantism
381
Elevated growth hormone (adult onset)
Acromegaly
382
Heterogenous group of multifactorial, polygenic syndromes characterized by an elevated fasting blood glucose caused by a relative or absolute deficiency in insulin
Diabetes Mellitus
383
Characterized by an absolute deficiency of insulin caused by an autoimmune attack on the beta cells of the pancreas
Type 1 DM
384
Characterized by a combination of insulin resistance and dysfunctional beta cells (defective receptors of target cells or organs)
Type 2 DM
385
Juvenile onset DM / Insulin Dependent DM
Type 1 DM
386
Adult onset DM / Non-insulin Dependent DM
Type 2 DM
387
Most common in children and young adults DM
Type 1 DM
388
Most common with advancing age DM
Type 2 DM
389
Frequency of Type 1 DM
5 - 10%
390
Frequency of Type 2 DM
90 - 95%
391
Autoantibodies in Type 1 DM
Anti-islet cell cytoplasmic antibody
Insulin autoantibodies
Anti-GAD
392
Genetic has a stronger effect in this Type of DM
Type 2 DM
393
Pathogenesis: Destruction of pancreatic beta cells, usually autoimmune
Type 1 DM
394
Pathogenesis: No autoimmunity; insulin resistance and progressive insulin deficiency
Type 2 DM
395
C- peptide levels in Type 2 DM
Detectable
396
Type of DM where the plasma insulin is high in early disease; low to absent in disease of long duration
Type 2 DM
397
Type of DM prone to keto acidosis and diabetic complications due to uncontrolled lipolysis
Type 1 DM
398
Ketone bodies and their percentages
Beta-hydroxybutyric acid - 78%
Acetoacetic acid - 20%
Acetone - 2%
399
Glucose intolerance with onset or first recognition during pregnancy
Gestational Diabetes Mellitus
400
Large % of patients develop DM in GDM within ___ years
5 to 10 years
401
Screening for GDM
2-hour GTT using a 75 g glucose load
402
Diagnostic criteria for DM
Random plasma glucose
>/= 200 mg/dl
403
Diagnostic criteria for DM
Fasting plasma glucose
>/= 126 mg/dl
404
Diagnostic criteria for DM
Two-h plasma glucose
>/= 200 mg/dl
405
Symptoms of DM
polyuria, polydypsia, polyphagia
406
Normal fasting plasma glucose
< 100 mg/dl
407
Normal 2-hour plasma glucose level (after 75 g load)
< 140 mg/dl
408
HbA1c prediabetes range
5.7 - 6.4%
409
Impaired fasting glucose level
100 - 125 mg/dl
410
Impaired glucose tolerance level
140 - 199 mg/dl
411
Fasting plasma glucose level for DM
>/=126 mg/dl
412
2-hour plasma glucose level for DM
>/= 200 mg/dl
413
Detection of GDM
Oral Glucose Tolerance Test
414
Before an OGTT is performed, individuals should ingest at least ___ of carbohydrates for 3 days preceding the test
150 g/day
415
Fasting duration for OGTT
8-14 hours
416
In OGTT, an FBG greater than ___ necessitates that the test be stopped immediately.
140 mg/dl
417
Glucose load for adults
75 g
418
Glucose load for children
1.75 g/kg body weight
419
Glucose load for pregnant women
75 g or 100 g
420
Patient should finish glucose load within ___
5 - 15 minutes
421
Patient should not vomit. If patient vomits, ___
discontinue the test
422
Gestational diabetes Mellitus is diagnosed if ___ are exceeded
>/= 2 plasma glucose levels
423
Rate of formation of HbA1c is proportional to the average blood glucose concentration over the previous ___
3 months
424
For every 1% increase in HbA1c, there is corresponding ___ change in plasma glucose
35 mg/dl
425
The Ada also recommends that a HbA1c be tested ___ to monitor long-term glycemic control
at least twice a year
426
False decrease HbA1c
decreased RBC lifespan
427
Glycated albumin
Fructosamine
428
Fructosamine monitors glucose control over past ___
2 - 3 weeks
429
Lifespan of albumin in circulation
20 days
430
False decrease in Fructosamine testing
Hypoalbuminemia
431
At about ____, glucagon and other glycemic factors are released
50 - 55 mg/dl
432
Insulinoma, various liver disorders, and gastrointestinal disorders and surgery all causes hypoglycemia
T
433
Whipple's Triad
Fasting hypoglycemia (<50 mg/dl)
Symptoms of hypoglycemia
Immediate relief of symptoms with intravenous glucose
434
Warning signs and symptoms of hypoglycemia are all related to the central nervous system
True
435
Test for hypoglycemia in which the glucose values drop around 4 and 5 hours
5-h OGTT
436
Test for hypoglycemia in which normal individuals can maintain glucose levels at normal levels within 3 days; noticeable drop in blood glucose over the 3 days of the fast
72-h fast
437
Half-life of albumin
30 days
438
target HbA1c
7%
439
Controlled DM
<7%
440
Uncontrolled DM
>7%
441
Controlled DM is tested every
6 months
442
Uncontrolled DM is tested every
3 months
443
Standard clinical specimen for glucose testing
Fasting venous plasma
444
Fasting blood sugar should be obtained after ___ of fasting
8 - 10 hours
445
Whole blood glucose levels ___ VS plasma levels
10 - 15% lower
446
Glucose is metabolized at room temperature at a rate of ___
7 mg/dl/hr
447
At 4 deg C, glucose decreases by approximately ___
2 mg/dl/hr
448
Evacuated tube for glucose testing
gray top (for long delay)
449
Anticoagulant in gray top tube
Sodium oxalate
450
Antiglycolytic agent in gray top tube
Sodium fluoride
451
Alternative Antiglycolytic agent in gray top tube
Iodoacetate
452
CSF glucose levels ___ of plasma levels
60 - 70%
453
As little as 10% contamination with 5% dextrose will elevate glucose in a sample by ___
500 mg/dl or more
454
Prevention of dextrose contamination.
Stop the line, wait for ___, discard 1st tube, the 2nd tube is used for analysis
5 - 10 mins
455
CSF glucose ___ in bacterial meningitis
decreases
456
Methods for Glucose measurement (2)
Chemical, Enzymatic
457
Method of glucose measurement that relies on the reducing property of sugars
Chemical method
458
Glucose and other carbohydrates are capable of converting cupric ions in alkaline solution to cuprous ions
Chemical method
459
Chemical methods of glucose measurement (2)
Oxidation-reduction method and Condensation method
460
Oxidation-reduction method for glucose measurement (2)
Alkaline Copper Reduction method and Alkaline Ferric Reduction method
461
Alkaline Copper Reduction method (4)
Folin-Wu
Nelson-Somogyi
Neocuproine method
Benedict'S method
462
Hagedorn-Jensen method
Alkaline Ferric Reduction method
463
Dubowski method
Condensation method
464
Enzymatic methods of glucose measurement (2)
Glucose oxidase method
Hexokinase method
465
Glucose oxidase method (2)
Colorimetric method and Polarographic method
466
Most specific enzyme reacting with only beta-D-glucose
Glucose oxidase
467
Cu + phosphomolybdate --> phosphomolybdenum blue
Folin-Wu
468
Cu + arsenomolybdate -> arsenomolybdenum blue
Nelson-Somogyi
469
Glucose oxidase method that uses a side reaction that consumes H2O2
Colorimetric method
470
Glucose oxidase method that measures the rate of disappearance of oxygen using an oxygen electrode
Polarographic method
471
Reference method for glucose determination
Hexokinase method
472
More accurate than glucose oxidase methods Because the coupling reaction using G6PDH is highly specific; therefore it has less interference than the coupled glucose oxidase procedure
Hexokinase method
473
NADPH has a strong absorbance at ___
340 nm
474
Hexokinase method is not affected by ascorbic acid or uric acid
T
475
Most common cause of lactose intolerance
Lactase deficiency
476
Congenital deficiency of one of three enzymes involved in galactose metabolism, resulting in increased levels of galactose in plasma
Galactosemia
477
Classic galactosemia; most common; usually presents with hepatomegaly, jaundice, hypoglycemia, convulsions, cataracts and lethargy
Galactose-1-phosphate uridyl transferase
478
May result in cataract development but otherwise asymptomatic unlike the more severe classic galactosemia
Galactokinase
479
Result of the deficiency of a specific enzyme that causes an alternation of glycogen metabolism
Glycogen storage diseases
480
Most common congenital form of glycogen storage disease
Von Gierke Disease
481
Autosomal recessive disease, characterized by hepatomegaly, severe hypoglycemia, metabolic acidosis, ketonemia, and elevated lactate and alanine; G6P deficiency
Von Gierke Disease
482
Types of Glycogen storage diseases
"Viagra Pill Causes A Muscle Hardening Tight"
"GG Di Ba MaLi Po"
Von Gierke - Glucose-6-phosphatase
Pompe - Glucosidase
Cori/Forbes - Debranching enzyme
Andersen - Branching enzyme
McArdle - Muscle phorphorylase
Hers - Liver phosphorylase
Tarui's disease - Phosphorylase
483
