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AMT MLT Study Guide > Clinical Chemistry > Flashcards

Clinical Chemistry Flashcards

1
Q

analytes affected by diurnal variation

A

increased in AM: ACTH, cortisol, iron

increased in PM: growth hormone, PTH, TSH

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2
Q

analytes affected by day-to-day variation

A

> =20% for ALT, bili, CK, steroid hormones, triglycerides

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3
Q

analytes affected by recent food ingestion

A

increased: glucose, insulin, gastrin, triglycerides, sodium, uric acid, iron, LD, calcium
decreased: chloride, phosphate, potassium

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4
Q

analytes that require the patient to be fasting

A

fasting glucose
trigylcerides
lipid panel

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5
Q

analytes affected by alcohol

A

decreased: glucose
increased: triglycerides, GGT

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6
Q

analytes affected by posture

A

increased albumin, cholesterol, calcium when standing

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7
Q

analytes affected by activity

A

increased in ambulatory patients: creatinine kinase (CK)

increased with exercise: potassium, phosphate, lactic acid, creatinine, protein, CK, AST, LD

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8
Q

analytes affected by stress

A

increased: ACTH, cortisol, catecholamines

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9
Q

analytes affected by age, gender, race, drugs

A

various

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10
Q

analytes affected by the use of isopropyl alcohol wipes to disinfect venipuncture site

A

blood alcohol

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11
Q

analytes affected by squeezing the site of a capillary puncture

A

increased potassium

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12
Q

analytes affected by pumping fist during venipuncture

A

increased: potassium, lactic acid, calcium, phosphorus
decreased: pH

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13
Q

analytes affected by applying the tourniquet >1 minute

A

increased: potassium, total protein, lactic acid

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14
Q

analytes affected by IV fluid contamination

A

increased: glucose, potassium, sodium, chloride (depending on IV)

possible dilution of other analytes

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15
Q

analytes affected by incorrect anticoagulant or contamination from incorrect order of draw

A

K2EDTA: decreased calcium, magnesium; increased potassium

sodium heparin: increased sodium if tube not completely filled

lithium heparin: increased lithium

gels: some interfere with trace metals and certain drugs

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16
Q

analytes affected by hemolysis

A

increased: potassium, magnesium, phosphorus, LD, AST, iron, ammonia

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17
Q

analytes affected by exposure to light

A

decreased bilirubin, carotene

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18
Q

analytes affected by temperature between collection and testing

A

chilling required for lactic acid, ammonia, blood gases

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19
Q

analytes affected by inadequate centrifugation

A

poor barrier formation in gel tubes can result in increased potassium, LD, AST, iron, phosphorus

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20
Q

analytes affected by recentrifugation of primary tubes

A

hemolysis, increased potassium

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21
Q

analytes affected by delay in separating serum/plasma (unless gel tube is used)

A

increased: ammonia, lactic acid, potassium, magnesium, LD
decreased: glucose (unless collected in fluoride)

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22
Q

analytes affected by storage temperature

A

decreased at RT: glucose (unless collected in fluoride)
increased at RT: lactic acid, ammonia
decreased at 4C: LD
increased at 4C: ALP

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23
Q

higher in plasma than serum

A

total protein
LD
calcium

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24
Q

higher in serum than plasma

A 
potassium
phosphate
glucose
CK
bicarbonate
ALP
albumin
AST
triglycerides
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25
higher in plasma than whole blood
glucose
26
higher in capillary blood than venous blood
glucose (in post-prandial specimen) | potassium
27
higher in venous blood than capillary blood
calcium | total protein
28
higher in RBCs than plasma
potassium phosphate magnesium
29
higher in plasma than RBCs
sodium | chloride
30
chemical reaction produces colored substance that absorbs light of a specific wavelength; amount of light absorbed is directly proportional to concentration of analyte
spectrophotometry
31
light source of spectrophotometer
tungsten lamp for visible range | deuterium lamp for UV
32
component parts of spectrophotometer
``` light source monochromator (diffraction grating) cuvette photodetector readout device ```
33
measures light absorbed by ground-state atoms; hollow cathode lamp with cathode made of analyte produces wavelength specific for analyte; sensitive
atomic absorption spectrophotometry
34
component parts of an atomic absorption spectrophotometer
``` hollow cathode lamp atomizer flame mixing chamber chopper monochromator detector readout device ```
35
used to measure trace metals
atomic absorption spectrophotometer
36
atoms absorb light of specific wavelength and emit light of longer wavelength (lower energy); detector at 90* to light source so that only light emitted by sample is measured
fluorometry
37
component parts of fluorometer
``` light source primary monochromator sample holder (quartz cuvettes) secondary monochromator detector readout device ```
38
light source of a fluorometer
mercury or xenon arc lamp
39
more sensitive than colorimetry and is used to measure drugs and hormones
fluorometry
40
chemical reaction that produces light; usually involves oxidation of luminol, acridinium esters, or dioxetanes
chemiluminescence
41
component parts of chemiluminescence
reagent probes sample and reagent cuvette photomultiplier tube readout device
42
used for immunoassays; doesn't require excitation radiation or monochromators like fluorometry; extremely sensitive
chemiluminescence
43
measures reduction in light transmission by particles in suspension
turbidmetry
44
component parts of turbidmetry
``` light source lens cuvette photodetector readout device ```
45
used to measure proteins in urine and CSF
turbidmetry
46
similar to turbidity, but light is measured at an angle form light source
nephelometry
47
component parts of nephelometry
``` light source collimator monochromator cuvette photodetector readout device ```
48
used to measure ag-ab reactions
nephelometry
49
wavelength 350-430 color absorbed? color transmitted (color seen)?
absorbed: violet transmitted: yellow
50
wavelength 430-475 color absorbed? color transmitted (color seen)?
absorbed: blue transmitted: orange
51
wavelength 475-495 color absorbed? color transmitted (color seen)?
absorbed: blue-green transmitted: red-orange
52
wavelength 495-505 color absorbed? color transmitted (color seen)?
absorbed: green-blue transmitted: orange-red
53
wavelength 505-555 color absorbed? color transmitted (color seen)?
absorbed: green transmitted: red
54
wavelength 555-575 color absorbed? color transmitted (color seen)?
absorbed: yellow-green transmitted: violet-red
55
wavelength 575-600 color absorbed? color transmitted (color seen)?
absorbed: yellow transmitted: violet
56
wavelength 600-650 color absorbed? color transmitted (color seen)?
absorbed: orange transmitted: blue
57
wavelength 670-700 color absorbed? color transmitted (color seen)?
absorbed: red transmitted: green
58
wavelength 220-380 range? common light source? cuvette?
near-ultraviolet deuterium or mercury arc quartz (silica)
59
wavelength 380-750 range? common light source? cuvette?
visible incandescent tungsten or tungsten-iodide borosilicate
60
wavelength 750-2,000 range? common light source? cuvette?
near-infrared incandescent tungsten or tungsten-iodide quartz (silica)
61
use of thin-layer chromatography
screening test for drugs of abuse in urine
62
use of high-performance liquid chromatography
separation of thermolabile compunds
63
use of gas chromatography
separation of volatile compounds or compounds that can be made volatile, e.g., therapeutic or toxic drugs
64
potential difference between 2 electrodes directly related to concentration of analyte
ion-selective electrodes
65
use of ion-selective electrodes
pH, Pco2, Po2, sodium, potassium, calcium, lithium, chloride
66
determines osmolality based on freezing-point depression
osmometry
67
measurement of number of dissolved particles in solution, irrespective of molecular weight, size, density or type
osmolality
68
use of osmometry
serum and urine osmolality
69
separation of charged particles in electrical field; anions move to positively charged pole (anode); cations move to negatively charge pole (cathode); the greater the charge, the faster the migration
electrophoresis
70
use of electrophoresis
serum protein electrophoresis, hemoglobin electrophoresis
71
List analytes tested in a BMP.
``` sodium potassium chloride CO2 glucose creatinine BUN calcium ```
72
List analytes tested in a CMP.
``` sodium potassium chloride CO2 glucose creatinine BUN calcium albumin total protein ALP AST bilirubin ```
73
List analytes tested in a electrolyte panel.
sodium potassium chloride CO2
74
List analytes tested in a hepatic function panel.
``` albumin ALT AST ALP bilirubin (total and direct) total protein ```
75
List analytes tested in a lipid panel.
total cholesterol HDL LDL triglycerides
76
List analytes tested in a renal function panel.
``` sodium potassium CO2 glucose creatinine BUN calcium albumin phosphate ```
77
reference range of fasting glucose
70-99 mg/dL
78
clinical significance of increased fasting glucose
``` (hyperglycemia) diabetes mellitus other endocrine disorders acute stress pancreatitis ```
79
clinical significance of decreased fasting glucose
(hypoglycemia) insulinoma insulin-induced hypoglycemia hypopituitarism
80
major source of cellular energy
glucose
81
most common methods of measuring glucose
glucose oxidase | hexokinase (more accurate, fewer interfering substances)
82
Does glucose increase or decrease at RT?
decreases
83
desirable range for total cholesterol
<200 mg/dL
84
most common method of measuring total cholesterol
enzymatic methods
85
clinical significance of total cholesterol
limited value for predicting risk of CAD by itself; used in conjunction with HDL and LDL cholesterol
86
desirable range for HDL cholesterol
>=60 mg/dL
87
clinical significance of HDL cholesterol
appears to be inversely related to CAD
88
most common method for measuring HDL cholesterol
homogeneous assay don't require pre-treatment to remove non-HDL; the first reagent blocks non-HDL, the second reacts with HDL
89
optimal range for LDL cholesterol
<100 mg/dL
90
clinical significance of LDL cholesterol
risk factor for CAD
91
method for measuring LDL cholesterol
may be calculated from Friedewald formula (if triglycerides not >400 mg/dL) or measure by direct homogeneous assays
92
desirable range for triglycerides
<150 mg/dL
93
clinical significance of triglycerides
risk factor for CAD
94
main form of lipid storage
triglycerides
95
method for measuring triglycerides
enzymatic methods using lipase
96
reference range for total protein
6.4-8.3 g/dL
97
clinical significance of elevated total protein
dehydration chronic inflammation multiple myeloma
98
clinical significance of decreased total protein
``` nephrotic syndrome malabsorption overhydration hepatic insufficiency malnutrition agammaglobulinemia ```
99
What is <4.5 g/dL of total protein associated with?
peripheral edema
100
method for measuring total protein
Biuret method; alkaline copper reagent reacts with peptide bonds
101
reference range for albumin
3.5-5.0 g/dL
102
clinical significance of elevated albumin
dehydration
103
clinical significance of decreased albumin
malnutrition liver disease nephrotic syndrome chronic inflammation
104
largest fraction of plasma proteins
albumin
105
protein synthesized by the liver
albumin
106
plasma protein that regulates osmotic pressure
albumin
107
method for measuring albumin
dye binding e.g., bromocresol green (BCG), bromocresol purple (BCP)
108
reference range for microalbumin (on urine)
50-200 mg/24 hr
109
clinical significance of increased urine microalbumin
risk of neprhopathy in diabetics
110
detects albumin in urine earlier than dipstick protein
microalbumin (urine)
111
method for measuring microalbumin
immunoassays on 24-hr urine; alternative is albumin-to-creatinine ratio on random sample
112
microalbuminuria
30-300 mg albumin/g creatinine
113
hormone that decreases glucose levels
insulin
114
responsible for entry of glucose into cells; increases glycogenesis
insulin
115
hormones that increase glucose levels
``` glucagon cortisol epinephrine growth hormone thyroxine ```
116
stimulates glycogenolysis and gluconeogenesis; inhibits glycolysis
glucagon
117
insulin antagonist; increases gluconeogenesis
cortisol
118
promotes glycogenolysis and gluconeogenesis
epinephrine
119
insulin antagonists
cortisol and growth hormone
120
increases glucose absorption from GI tract; stimulates glycogenolysis
thyroxine
121
DM caused by autoimmune destruction of beta cells
Type 1 DM
122
absolute insuline deficiency
Type 1 DM
123
DM with genetic predisposition (HLA-DR 3/4)
Type 1 DM
124
DM caused by secretory defect of beta cells
type 2 DM
125
insulin resistance in peripheral tissue
type 2 DM
126
DM associated with obesity
type 2 DM
127
DM caused by placental lactogen inhibiting the action of insulin
Gestational diabetes mellitus (GDM)
128
complications of gestational diabetes mellitus
intrauterine death | neonatal complications: macrosomia, hypoglycemia, hypocalcemia, polycythemia, hyperbilirubinemia
129
DM: random plasma glucose
>=200 mg/dL
130
patient prep for fasting plasma glucose
fast of at least 8 hrs
131
DM: fasting plasma glucose
>=126 mg/dL on 2 occasions
132
patient prep for 2 hr plasma glucose
75-g glucose load
133
DM: 2-hr plasma glucose
>=100 mg/dL on 2 occasions
134
patient prep for oral glucose tolerance test (OGTT)
fast of at least 8 hours; 75-g glucose load
135
DM: oral glucose tolerance test (OGTT)
fasting >=92 mg/dL OR 1 hr >=180 OR 2 hr >=153
136
When is an oral glucose tolerance test performed on pregnant women?
24-28 weeks of gestation
137
DM: hemoglobin A1C
>=6.5%
138
gives an estimate of glucose control over previous 2-3 months
hemoglobin A1C
139
Is blood glucose INCREASED or DECREASED in uncontrolled DM?
INCREASED
140
Is urine glucose INCREASED or DECREASED in uncontrolled DM?
INCREASED
141
Is urine specific gravity INCREASED or DECREASED in uncontrolled DM?
INCREASED
142
Is glycohemogobin INCREASED or DECREASED in uncontrolled DM?
INCREASED
143
Are blood and urine ketones INCREASED or DECREASED in uncontrolled DM?
INCREASED
144
Is the anion gap INCREASED or DECREASED in uncontrolled DM?
INCREASED
145
Is the BUN INCREASED or DECREASED in uncontrolled DM?
INCREASED
146
Are serum and urine osmolality INCREASED or DECREASED in uncontrolled DM?
INCREASED
147
Is cholesterol INCREASED or DECREASED in uncontrolled DM?
INCREASED
148
Are triglycerides INCREASED or DECREASED in uncontrolled DM?
INCREASED
149
Is bicarbonate INCREASED or DECREASED in uncontrolled DM?
DECREASED
150
Is blood pH INCREASED or DECREASED in uncontrolled DM?
DECREASED
151
group of risk factors that seem to promote development of atherosclerotic cardiovascular disease and type 2 diabetes mellitus
metabolic syndrome
152
List the risk factors of metabolic syndrome.
``` decreased HDL-C increased LDL-C increased triglycerides increased blood pressure increased blood glucose ```
153
aminoacidopathy caused by a deficiency of an enzyme that converts phenylalanine to tyrosine; phenylpyruvic acid in the blood and urine
phenylketonuria
154
effect of phenylketonuria
mental retardation | urine has a "mousy" odor
155
diagnosis of phenylketonuria
Guthrie bacterial inhibition assay HPLC tandem mass spec (MS/MS) fluorometric and enzymatic methods
156
aminoacidopathy caused by a disorder of tyrosine catabolism; tyrosine and its metabolites are excreted in urine
tyrosinemia
157
effect of tyrosinemia
liver and kidney disease | death
158
diagnosis of tyrosinemia
MS/MS
159
aminoacidopathy caused by a deficiency of an enzyme needed in metabolism of tyrosine and phenylalanine; buildup of homogenistic acid
alkaptonuria
160
effect of alkaptonuria
diapers stain black due to homogenistic acid in urine later in life - darkening of tissues, hip and back pain
161
diagnosis of alkaptonuria
gas chromatography | mass spectroscopy
162
aminoacidopathy caused by enzyme deficiency leading to buildup of leucine, isoleucine, and valine
maple syrup urine disease (MSUD)
163
effect of maple syrup urine disease
``` burnt-sugar odor to urine, breath, and skin failure to thrive mental retardation acidosis seizures coma death ```
164
diagnosis of maple syrup urine disease
modified Guthrie test | MS/MS
165
aminoacidopathy caused by deficiency in enzyme needed for metabolism of methionine; methionine and homocysteine build up in plasma and urine
homocystinuria
166
effect of homocystinuria
osteoporosis dislocated lenses in eye mental retardation thromboembolic events
167
diagnosis of homocystinuria
Guthrie test MS/MS LC-MS/MS
168
aminoacidopathy caused by increased excretion of cystine due to defect in renal reabsorption
cystinuria
169
effect of cystinuria
recurring kidney stones
170
diagnosis of cystinuria
test urine with cyanide nitroprusside | POS = red-purple color
171
During protein electrophoresis, what does rate of migration depend on?
size shape charge of molecule
172
support medium for protein electrophoresis
cellulose acetate or agarose
173
buffer for protein electrophoresis
barbital buffer, pH 8.6
174
stains used for protein electrophoresis
Ponceau S amido blue bromphenol blue Coomassie brilliant blue
175
charge for protein electrophoresis
at pH 8.6, proteins are negatively charged and move toward the anode
176
order of migration (fastest to slowest) of proteins during protein electrophoresis
``` albumin alpha-1 globulin alpha-2 globulin beta globulin gamma globulin ```
177
largest fraction of protein
albumin
178
buffer flow toward cathode; causes gamma region to be cathodic to point of application
electroendosmosis
179
Why must urine be concentrated first before performing protein electrophoresis?
because of low protein concentration in urine
180
Where do Bence Jones proteins migrate during urine electrophoresis?
migrate to the gamma region
181
Why must CSF be concentrated first before performing protein electrophoresis?
because of low protein concentration in CSF
182
What protein band does CSF have that urine doesn't in electrophoresis?
CSF has a prealbumin band
183
serum protein electrophoresis: acute inflammation
increased alpha-1 and alpha-2
184
serum protein electrophoresis: chronic inflammation
increased alpha-1, alpha-2, and gamma
185
serum protein electrophoresis: cirrhosis
polyclonal increase (all fractions) in gamma with beta-gamma bridging
186
serum protein electrophoresis: monoclonal gammaopathy
sharp increase in 1 immunoglobulin ("M spike"), decrease in other fractions
187
serum protein electrophoresis: polyclonal gammopathy
diffuse increase in gamma
188
serum protein electrophoresis: hypogammglobulinemia
decreased gamma
189
serum protein electrophoresis: nephrotic syndrome
decreased albumin | increased alpha-2
190
serum protein electrophoresis: alpha-1-antitrypsin deficiency
decreased alpha-1
191
serum protein electrophoresis: hemolyzed specimen
increased beta or unusual band between alpha-2 and beta
192
serum protein electrophoresis: plasma
extra band (fibrinogen) between beta and gamma
193
List the non-protein nitrogen compounds.
BUN creatinine uric acid ammonia
194
reference range for BUN
8-26 mg/dL
195
clinical significance of increased BUN
kidney disease
196
clinical significance of decreased BUN
overhydration or liver disease
197
Where is BUN synthesized?
in the liver from ammonia
198
Where is BUN excreted?
kidneys
199
What reagent is used to test for BUN?
urease reagent
200
reference range for creatinine
0-7-1.5 mg/dL
201
clinical significance of increased creatinine
kidney disease
202
waste product from dehydration of creatine (mainly in muscles)
creatinine
203
methods for measuring creatinine
Jaffe's reaction (alkaline picrate) - nonspecific enzymatic methods
204
normal BUN:creatinine ratio
12-20
205
reference range for uric acid
males: 3.5-7.2 mg/dL females: 2.6-6.0 mg/dL
206
clinical significance of increased uric acid
``` gout renal failure ketoacidosis lactate excess high nucleoprotein diet leukemia lymphoma polycythemia ```
207
clinical significance of decreased uric acid
administration of ACTH | renal tubular defects
208
method for measuring uric acid
uricase method
209
Which tube additives interfere with uric acid?
EDTA and fluoride
210
What do you do to a urine specimen to prevent precipitation of uric acid?
adjust urine pH to 7.5-8.0
211
Increased uric acid increases risk of __________ and _______________.
renal calculi and joint trophi
212
reference range of ammonia
19-60 ug/dL
213
clinical significance of increased ammonia
liver disease hepatic coma renal failure Reye's syndrome
214
site of ammonia production
GI tract
215
high levels of ammonia (toxicity)
neurotoxic
216
tubes that should be used for ammonia
EDTA or heparin
217
Why should serum tubes not be used to collect specimens for ammonia?
may cause increased levels as NH3 is generated during clotting
218
reference range for sodium
136-145 mmol/L
219
clinical significance of increased sodium (hypernatremia)
``` increased sodium intake or IV admin hyperaldosteronism excessive sweating burns diabetes insipidus ```
220
effects of hypernatremia
tremors irritability confusion coma
221
clinical significance of decreased sodium (hyponatremia)
renal or extrarenal loss (vomiting, diarrhea, sweating, burns) increased extracellular volume
222
effects of hyponatremia
weakness nausea altered mental status
223
major extracellular cation
sodium
224
contributes to almost half to plasma osmolality
sodium
225
maintains normal distribution of water and osmotic pressure
sodium
226
regulates sodium levels
aldosterone
227
most common method of sodium measurement
ion-selective electrode
228
normal sodium/potassium ratio in serum
approx. 30:1
229
reference range of potassium
3.5-5.1 mmol/L
230
clinical significance of increased potassium (hyperkalemia)
increased intake decreased excretion crush injuries metabolic acidosis
231
effects of hyperkalemia
muscle weakness confusion cardiac arrythmia cardiac arrest
232
clinical significance of decreased potassium (hypokalemia)
increased GI or urinary loss use of diuretics metabolic alkalosis
233
effects of hypokalemia
``` muscle weakness paralysis breathing problems cardiac arrythmia death ```
234
major intracellular cation
potassium
235
causes of artificial potassium increases
``` squeezing site of capillary puncture prolonged tourniquet pumping fist during venipuncture contamination with IV fluids hemolysis prolonged contact with RBCs leukocytosis thrombocytosis ```
236
Why are serum values 0.1-0.2 mmol/L higher than plasma?
due to release from platelets during clotting
237
most common method of measuring potassium
ISE with valinomycin membrane
238
reference range for chloride
98-107 mmol/L
239
clinical significance of increased chloride (hyperchloremia)
``` increased intake IV administration hyperaldosteronism excessive sweating burns DI excess loss of HCO3- ```
240
clinical significance of decreased chloride (hypochloremia)
``` prolonged vomiting diabetic ketoacidosis aldosterone deficiency salt-losing renal diseases metabolic alkalosis compensated respiratory acidosis ```
241
major extracellular ion
chloride
242
helps maintain osmolality, blood volume, electric neutrality
chloride
243
passively follows sodium
chloride
244
most common method of measuring chloride
ISE
245
sweat chloride test
test for diagnosis of cystic fibrosis
246
reference range for CO2, total
23-29 mmol/L
247
clinical significance of increased CO2, total
metabolic alkalosis | compensated respiratory acidosis
248
clinical significance of decreased CO2, total
metabolic acidosis | compensated respiratory alkalosis
249
What percentage of CO2 total is bicarbonate (HCO3-)? What makes up the remaining percentage?
>90% carbonic acid (H2CO3-) and dissolved CO2
250
important in maintaining acid-base balance
CO2
251
Why should a CO2 specimen remain capped?
to prevent loss of CO2
252
method of measuring CO2
ISE or enzymatic method
253
reference range for magnesium
1.6-2.6 mg/dL
254
clinical significance of increased magnesium
``` renal failure increased intake (e.g., antacids) dehydration bone cancer endocrine disorders ```
255
effects of increased magnesium
cardiac abnormalities paralysis respiratory arrest coma
256
clinical significance of decreased magnesium
severe illness GI disorders endocrine disorders renal loss **rare in non-hospitalized patients**
257
effects of decreased magnesium
``` cardiac arrythmias tremors tetany paralysis psychosis coma ```
258
analyte that is an essential cofactor for many enzymes
magnesium
259
Why should you avoid hemolyzing a specimen being tested for magnesium?
because magnesium is 10x more concentrated in RBCs and will falsely elevate results
260
Why should you not collect a specimen for magnesium testing in a tube with EDTA, citrate, or oxalate?
because they bind magnesium and results will be falsely decreased
261
method of measuring magnesium
colorimetric methods
262
reference range for total calcium
8.6-10.0 mg/dL
263
reference range for ionized calcium
4.60-5.08 mg/dL
264
clinical significance of increased calcium
primary hyperparathyroidism cancer multiple myeloma
265
effects of increased calcium
weakness coma GI symptoms renal calculi
266
clinical significance of decreased calcium
hypoparathyroidism malabsorption vitamin D deficiency renal tubular acidosis
267
effects of decreased calcium
tetany (muscle spasms) seizures cardiac arrythmias
268
most abundant mineral in body
calcium
269
Where is 99% of calcium located in the body?
bones
270
What 3 analytes regulate calcium?
PTH vitamin D calcitonin
271
Why should you not use tubes with anticoagulants other than heparin?
because they bind calcium
272
method for measuring total calcium
colorimetric methods
273
biologically active form of calcium and a better indicator of calcium status
ionized calcium
274
method for measuring ionized calcium
ISE
275
What is the ionized calcium value affected by?
pH and temperature
276
reference range for phosphorus, inorganic (phosphate)
2.5-4.5 mg/dL
277
clinical significance of increased phosphorus
renal disease | hypoparathyroidism
278
clinical significance of decreased phosphorus
hyperparathyroidism vitamin D deficiency renal tubular acidosis
279
major intracellular anion
phosphorus
280
Where is phosphorus mostly found?
bones
281
important reservoir for energy (ATP); component of nucleic acids, many coenzymes
phosphorus
282
What analyte should phosphorus be correlated with?
calcium | normally reciprocal relationship
283
True or False. Phosphorus is usually higher in children.
True
284
Which tube additive interfere with phosphorus?
citrate oxalate EDTA
285
Is phosphorus higher in RBCs or plasma?
RBCs
286
reference range for lactate (lactic acid)
4.5-19.8 mg/dL
287
clinical significance of lactate (lactic acid)
sign of decreased oxygen to tissues
288
What is lactate a byproduct of?
anaerobic metabolism
289
reference range for iron
M: 65-175 ug/dL F: 50-170 ug/dL
290
clinical significance of increased iron levels
``` iron overdose hemochromatosis sideroblastic anemia hemolytic anemia liver disease ```
291
clinical significance of decreased iron levels
iron deficiency anemia
292
What is iron necessary for?
hemoglobin synthesis
293
What is iron transported by?
transferrin
294
Does hemolysis interfere with iron tests?
yes
295
What tube additives bind iron?
oxalate citrate EDTA
296
Why are early morning specimens preferred for iron tests?
because of diurnal variation
297
reference range for total iron binding capacity (TIBC)
250-425 ug/dL
298
clinical significance of increased TIBC
iron deficiency anemia
299
clinical significance of decreased TIBC
iron overdose | hemochromatosis
300
reference range for % saturation or transferrin saturation
20-50%
301
clinical significance of increased % saturation or transferrin saturation
iron overdose hemochromatosis sideroblastic anemia
302
clinical significance of decreased % saturation or transferrin saturation
iron deficiency anemia
303
% saturation or transferrin saturation calculation
(100 x serum iron)/TIBC
304
reference range for transferrin
200-360 mg/dL
305
clinical significance of increased transferrin
iron deficiency anemia
306
clinical significance of decreased transferrin
iron overdose hemochromatosis chronic infections malignancies
307
complex of apotransferrin (protein that transports iron) and iron
transferrin
308
reference range for ferritin
M: 20-250 ug/L F: 10-120 ug/L
309
clinical significance of increased ferritin
iron overload hemochromatosis chronic infections malignancies
310
clinical significance of decreased ferritin
iron deficiency anemia
311
storage form of iron; rough estimate of body iron content
ferritin
312
How does substrate concentration influence enzymatic reactions?
first order kinetics: [enzyme] > [substrate] = reaction rate proportional to [substrate] zero order kinetics: [substrate] > [enzyme] = reaction rate proportional to [enzyme] **assays are zero order (excess substrate)**
313
How does enzyme concentration influence enzymatic reactions?
velocity of reaction is proportional to [enzyme] as long as [substrate] > [enzyme]
314
How does pH influence enzymatic reactions?
extremes of pH may denature enzymes
315
At what pH do most enzymatic reactions occur?
pH 7-8
316
How does temperature influence enzymatic reactions?
increase of 10*C doubles rate of reaction until around 40-50*C; then denaturation of enzyme may occur **37*C is most commonly used in the US**
317
nonprotein molecules that participate in enzymatic reactions and must be present in excess
cofactors
318
What are inorganic cofactors called?
activators
319
How do inorganic cofactors influence enzymatic reactions?
either required for or enhance reactions
320
What are organic cofactors called?
coenzymes
321
How do organic cofactors influence enzymatic reactions?
may serve as 2nd substrate in reaction
322
Give some examples of inorganic cofactors.
chloride, magnesium
323
Give an example of organic cofactors.
nicotinamide adenine dinucleotide
324
reaction commonly used in enzyme determinations
NAD NADH NADH = reduce form of NAD NADH has absorbance at 340 nm; NAD does not
325
How do inhibitors influence enzymatic reactions?
interfere with reaction
326
What tissue is the enzyme acid phosphatase (ACP) found?
prostate
327
clinical significance of increased acid phosphatase (ACP)
prostate cancer
328
What tissues is alkaline phosphatase (ALP)?
almost all tissues
329
clinical significance of increased ALP
liver and bone disease levels higher in biliary tract obstruction than in hepatocellular disorders (hepatitis, cirrhosis)
330
In what parts of the population is ALP increased?
children adolescents pregnant women healing bone fractures
331
optimum pH for ALP
pH 9-10
332
What tissues is aspartate aminotransferase (AST) found?
many; highest levels in liver, heart, and skeletal muscle
333
clinical significance of increased AST
liver disease (marked increase with viral hepatitis) acute myocardial infarction muscular dystrophy
334
Is AST affected by hemolysis?
yes
335
What tissues is alanine aminotransferase found?
liver | RBCs
336
clinical significance of increased ALT
liver disease (marked increase with viral hepatitis)
337
Which is more specific for liver disease, AST or ALT?
ALT
338
What tissues is gamma glutamyl transferase (GGT) found?
liver kidneys pancreas
339
clinical significance of increased GGT
hepatobiliary disorders | chronic alcoholism
340
most sensitive enzyme for all types of liver disease
GGT
341
Highest levels of GGT is found in what type of disorders?
obstructive
342
used by treatment centers to monitor abstention from alcohol
GGT
343
What tissues is lactate dehydrogenase (LD) found?
all tissues; highest in liver, heart, skeletal muscle, and RBCs
344
clinical significance of increased LD
AMI liver disease pernicious anemia
345
LD catalyzes lactic acid into __________.
pyruvic acid
346
storage temp for LD specimens
25*C, NOT 4*C
347
What tissues is creatine kinase (CK) found?
cardiac muscle skeletal muscle brain
348
clinical significance of increased CK
AMI | muscular dystrophy
349
function of CK
catalyzes phosphocreatine + ADP creatine + ATP
350
most sensitive enzyme fo skeletal muscle disease
CK
351
highest levels of LD
pernicious anemia
352
highest levels of CK
muscular dystrophy
353
anticoagulants that inhibit CK
all anticoagulants EXCEPT heparin
354
clinically insignificant causes of elevated CK
physical activity | IM injections
355
CK isoenzyme used in diagnosis of AMI
CK-MB
356
What tissues is amylase (AMS) found?
salivary glands | pancreas
357
clinical significance of increase amylase
acute pancreatitis other abdominal diseases mumps
358
function of amylase
breaks down starch to simple sugars
359
levels of amylase in acute pancreatitis
increase 2-12 hours after attack peak at 24 hours return to normal in 3-5 days
360
What tissues is lipase (LPS) found?
pancreas
361
clinical significance of increased lipase
acute pancreatitis
362
function of lipase
breaks down triglycerides into fatty acids and glycerol
363
more specific than amylase for pancreatic disease
lipase
364
levels of lipase in acute pancreatitis
levels usually parallel amylase but may stay increased longer
365
Where is glucose-6-phosphate dehydrogenase (G6PD) found?
RBCs
366
clinical significance of decreased G6PD
inherited deficiency can lead to drug-induced hemolytic anemia
367
method of measuring G6PD
measured in hemolysate of whole blood
368
enzymes used in diagnosing cardiac disorders
CK-MB
369
enzymes used in diagnosing hepatocellular disorders
AST ALT LD
370
enzymes used in diagnosing biliary tract obstructions
ALP | GGT
371
enzymes used in diagnosing skeletal muscle disorders
CK AST LD aldolase
372
enzymes used in diagnosing bone disorders
ALP
373
enzymes used in diagnosing acute pancreatitis
amylase | lipase
374
elevation of CK-MB after chest pain
4-6 hours
375
duration of elevation of CK-MB in AMI
2-3 days
376
sensitivity/specificity of CK-MB for AMI
not entirely specific for AMI
377
elevation of myoglobin after chest pain
1-4 hours
378
duration of myoglobin elevation in AMI
18-24 hours
379
sensitivity/specificity of myoglobin for AMI
sensitive but not specific
380
negative predictive maker for AMI
myoglobin **if not elevated within 8 hours of chest pain, AMI ruled out**
381
elevation of troponin after chest pain
4-10 hours
382
duration of troponin elevation for AMI
4-10 days
383
sensitivity/specificity of troponin for AMI
high sensitivity and specificity
384
considered definitive marker for AMI
troponin
385
tests for heart failure
B-type natriuretic peptide (BNP)
386
function of BNP
released from heart muscle of left ventricle when fluid builds from heart failure; acts on kidneys to increase excretion of fluid
387
nonspecific marker of inflammation
cardiac C-reactive protein (cCRP)
388
best single biomarker for predicting cardiovascular events
cardiac C-reactive protein (cCRP)
389
Why should cCRP be tested on 2 occasions?
because of individual variability
390
List the 5 tests used to assess risk of CAD
1. cardiac C-reactive protein 2. total cholesterol 3. HDL cholesterol 4. LDL cholesterol 5. triglycerides
391
reference range for total bilirubin
0.2-1.0 mg/dL
392
clinical significance of increased total bilirubin
liver disease hemolysis HDN
393
total bilirubin levels in infants associated with brain damage (kernicterus)
>20 mg/dL
394
sum of conjugated, unconjugated, and delta bilirubin
total bilirubin
395
reference range for conjugated bilirubin (direct bilirubin)
<0.2 mg/dL
396
clinical significance of increased conjugated bilirubin (direct bilirubin)
liver disease | obstructive jaundice
397
methods of measurement for TBIL and DBIL
Jendrassik-Grof method; Diazo reagent
398
reference range for unconjugated bilirubin (indirect bilirubin)
<0.8 mg/dL
399
clinical significance of increased unconjugated bilirubin (indirect bilirubin)
prehepatic, posthepatic and some types of hepatic jaundice
400
calculation for unconjugated bilirubin (indirect bilirubin)
Total bili minus direct bili
401
structure of unconjugated bilirubin
bilirubin
402
Is unconjugated bilirubin bound to protein?
yes - albumin
403
Is unconjugated bilirubin polar or nonpolar?
nonpolar
404
Is unconjugated bilirubin soluble in water?
no
405
Is unconjugated bilirubin present in urine?
no
406
Is the reaction between unconjugated bilirubin and diazotized sulfanilic acid indirect or direct?
indirect - only reacts in presence of accelerator
407
unconjugated bilirubin affinity for brain tissue
high
408
structure of conjugated bilirubin
bilirubin monoglucuronide bilirubin diglucuronide delta bilirubin
409
Is conjugated bilirubin bound to protein?
no (except delta bilirubin)
410
Is conjugated bilirubin polar or nonpolar?
polar
411
Is conjugated bilirubin soluble in water?
yes
412
Is conjugated bilirubin present in urine?
yes
413
Is the reaction between conjugated bilirubin and diazotized sulfanilic acid indirect or direct?
direct - reacts without accelerator
414
conjugated bilirubin affinity for brain tissue
low
415
``` Prehepatic jaundice: TBIL? DBIL? Urine bilirubin? Urine urobilinogen? ```
TBIL = increased DBIL = normal Urine bilirubin = negative Urine urobilinogen = increased
416
``` Hepatic jaundice: TBIL? DBIL? Urine bilirubin? Urine urobilinogen? ```
TBIL = increased DBIL = variable Urine bilirubin = variable Urine urobilinogen = decreased
417
``` Posthepatic jaundice: TBIL? DBIL? Urine bilirubin? Urine urobilinogen? ```
TBIL = increased DBIL = increased Urine bilirubin = positive Urine urobilinogen = decreased
418
List the 6 anterior pituitary hormones.
1. ACTH 2. FSH 3. Growth Hormone (GH) 4. LH 5. Prolactin (PRL) 6. TSH
419
regulates production of adrenocortical hormones by adrenal cortex
ACTH
420
clinical significance of increased ACTH
Cushing's disease
421
What is ACTH regulated by?
corticotropin-releasing hormon (CRH) from hypothalamus
422
ACTH - diurnal variation - levels in AM and PM?
highest levels in early AM | lowest in late afternoon
423
collection specifics for ACTH
collect on ice | store frozen
424
regulates sperm and egg production
FSH
425
What is FSH regulated by?
gonadotropin-releasing hormone (GnRH) from hypothalamus
426
What part of a woman's cycle does a sharp increase in FSH occur?
just before ovulation
427
regulates protein synthesis, cell growth, and divison
growth hormone (GH)
428
What is growth hormone regulated by?
GHRH and somatostatin from hypothalamus
429
clinical significance of increased GH
gigantism | acromegaly
430
clinical significance of decreased GH
dwarfism
431
regulates maturation of follicles, ovulation, production of estrogen, progesterone, testosterone
LH
432
What is LH regulated by?
GnRH from hypothalamus
433
What part of a woman's cycle does a sharp increase in LH occur?
just before ovulation
434
regulates lactation
Prolactin (PRL)
435
What is prolactin regulated by?
prolactin-releasing factor (PRF) and prolactin-inhibiting factor (PIF) from hypothalamus
436
regulates production of T3 and T4 by thyroid
TSH
437
What is TSH regulated by?
thyrotropin-releasing hormone (TRH) from hypothalamus
438
clinical significance of increased TSH
hypothyroidism
439
clinical significance of decreased TSH
hyperthyroidism
440
regulates reabsorption of water in distal renal tubules
ADH
441
Where is ADH produced?
hypothalamus
442
Where is ADH stored?
posterior pituitary
443
List the 2 posterior pituitary hormones.
ADH | oxytocin
444
stimulates release of ADH
increased osmolality | decreased blood volume or blood pressure
445
clinical significance of decreased ADH
diabetes insipidus
446
regulates uterine contractions during childbirth and lactation
oxytocin
447
Where is oxytocin produced?
hypothalamus
448
Where is oxytocin stored?
posterior pituitary
449
List the 3 thyroid hormones.
1. thyroxine (T4) 2. triiodothyronine (T3) 3. calcitonin
450
regulates metabolism, growth, and development
T4 and T3
451
principle thyroid hormone
T4
452
Where is most T4 found?
bound to TBG
453
clinical significance of increased T4
hyperthyroidism
454
clinical significance of decreased T4
hypothyroidism
455
regulated by TSH
T4 and T3
456
50x more concentrated than T3
T4
457
4-5x more potent than T4
T3
458
clinical significance of increased T3
hyperthyroidism
459
clinical significance of decreased T3
hypothyroidism
460
important in diagnosis of thyroid cancer
calcitonin
461
regulates inhibition of calcium resorption
calcitonin
462
functions in regulation of calcium and phosphate
parathyroid hormone (PTH)
463
Primary hyperthyroidism: PTH? Calcium? Phosphate?
``` PTH = increased Calcium = increased Phosphate = decreased ```
464
Hypoparathyroidism: PTH? Calcium? Phosphate?
``` PTH = decreased Calcium = decreased Phosphate = increased ```
465
Primary hypothyroidism: TSH? FT4? FT3?
``` TSH = increased FT4 = decreased FT3 = decreased ```
466
Secondary hypothyroidism: TSH? FT4? FT3?
``` TSH = decreased FT4 = decreased FT3 = decreased ```
467
Hyperthyroidism: TSH? FT4? FT3?
``` TSH = decreased FT4 = increased FT3 = increased ```
468
T3 Thyrotoxicosis: TSH? FT4? FT3?
``` TSH = decreased FT4 = normal FT3 = increased ```
469
biologically active form of T4
Free T4
470
regulates reabsorption of sodium in renal tubules
aldosterone
471
clinical significance of increased aldosterone
hypertension due to water and sodium rentention
472
clinical significance of decreased aldosterone
severe water and electrolyte abnormalities
473
regulates carbohydrate, fat, and protein metabolism; water and electrolyte balance
cortisol
474
suppresses inflammatory and allergic reactions
cortisol
475
What is cortisol regulated by?
ACTH
476
clinical significance of increased cortisol
Cushing's syndrome **loss of diurnal variation**
477
slinical significance of decreased cortisol
Addison's disease
478
Does cortisol show diurinal variation?
yes, highest in AM
479
List hormones of the adrenal cortex.
aldosterone | cortisol
480
List hormones of the adrenal medulla.
epinephrine, norepinephrine
481
regulates "fight or flight syndrome;"r regulates stimulation of sympathetic nervous system
epinephrine, norepinephrine
482
primary hormone of adrenal medulla
epinephrine
483
epinephrine and norepinephrine = ______
catecholeamines
484
metanephrines and VMA
metabolites
485
clinical significance of increased epinephrine/norepinephrine
pheochromocytoma (rare catecholamine producing tumor)
486
List hormones of ovaries.
estrogens | progesterone
487
regulates development of female reproductive organs and secondary sex characteristics
estrogens
488
regulates menstrual cycle
estrogens
489
regulates maintenance of pregnancy
estrogens
490
major estrogen produced by ovaries; most potent estrogen
estradiol
491
Where is estradiol produced other than the ovaries?
adrenal cortex
492
regulates preparation of uterus for ovum implantation and maintenance of pregnancy
progesterone
493
Where is progesterone produced other than the ovaries?
placenta
494
metabolite of progesterone
pregnanediol
495
hormone useful in infertility studies and to assess placental function
progesterone
496
hormone used to monitor fetal growth and development but has no hormonal activity
estrogen (estriol)
497
List hormones of the placenta.
estrogen (estriol) progesterone HCG human placental lactogen (HPL)
498
regulates progesterone production by corpus luteum during early pregnancy; development of fetal gonads
HCG
499
used to detect pregnancy, gestational trophoblastic disease (e.g., hydatidiform mole), testicular tumors, and other HCG-producing tumors
HCG
500
regulates estrogen and progesterone production by corpus luteum and development of mammary glands
human placental lactogen (HPL)
501
hormone used to assess placental function
human placental lactogen (HPL)
502
List hormones of the testes.
testosterone
503
regulates development of male reproductive organs and secondary sex characteristics
testosterone
504
Where is testosterone produced other than the testes?
adrenal cortex
505
List the 2 pancreatic hormones.
insulin | glucagon
506
regulates carbohydrate metabolism
insulin
507
Where is insulin produced in the pancreas?
beta cells of islets of Langerhans
508
causes increased movement of glucose into the cells for metabolism
insulin
509
clinical significance of decreased insulin
diabetes mellitus
510
clinical significance of increased insulin
insulinoma | hypoglycemia
511
regulates glycogenolysis, gluconeogenesis, lipolysis
glucagon
512
Where is glucagon produced in the pancreas?
alpha cells of islets of Langerhans
513
causes increases in plasma glucose levels
glucagon
514
clinical significance of increased glucagon
glucagonoma diabetes mellitus pancreatitis trauma
515
lowest concentration of drug in blood that will produce desired effect
minimum effective concentration (MEC)
516
lowest concentration of drug in blood that will produce adverse response
minimum toxic concentration (MTC)
517
ratio of MTC to MEC
therapeutic index
518
lowest concentration of drug measured in blood; reached just before next scheduled dose; shouldn't fall below MEC
trough
519
highest concentration of drug measured in blood; drawn immediately on achievement of steady state; should not exceed MTC
peak
520
amount of drug absorbed and distributed = amount of drug metabolized and excreted; usually reached after 5-7 half-lives
steady state
521
time required for concentration of drug to be decreased by half
half-life
522
rates of absorption, distribution, biotransformation, and excretion
pharmacokinetics
523
salicylates, acetaminophen
analgesics
524
phenobarbital, phenytoin, valproic acid, carbamazepine, ethosuximide, felbamate, gabapentin, lamotrigine
antiepileptics
525
methotrexate
antineoplastics
526
aminoglycosides, vancomycin
antibiotics
527
amikacin, gentamicin, kanamycin, tobramycin
aminoglycoside antibiotics
528
digoxin, disopyramide, procainamide, quinidine
cardioactives
529
tricyclic antidepressants, lithium
psychoactives
530
cyclosporine, tacrolimus (FK-506)
immunosuppressants
531
analytic methods for ethanol
gas chromatography | enzymatic methods
532
analytic methods for carbon monoxide
``` differential spectrophotometry (co-oximeter) gas chromatography ```
533
analytic methods for arsenic
atomic absorption
534
analytic methods for lead
atomic absorption
535
analytic methods for pesticides
measurement of serum pseudocholinesterase
536
value outside physiological range or presence of substance that isn't found in human urine
adulterated urine
537
values that aren't consistent with normal human urine
substituted urine
538
creatinine and specific gravity lower than expected for normal human urine
diluted urine
539
urine pH <3 or >11
adulterated urine
540
urine nitrite >=500 mg/dL
adulterated urine
541
presence of chromium, halogens (bleach, iodine, fluoride), glutaraldehyde, pyridine, or surfactant in urine
adulterated urine
542
creatinine <2 mg/dL and specific gravity <=1.0010 or >=1.0200
substituted urine
543
creatinine >=2 mg/dL but <=20 mg/dL and specific gravity >=1.0010 but <=1,0030
diluted urine
544
tumor marker for liver cancer
alpha-fetoprotein (AFP)
545
clinical use of AFP
aid diagnosis monitor therapy detect recurrence
546
produced by fetal liver; re-expressed in certain tumors
AFP
547
clinical significance of increased AFP
tumors hepatitis pregnancy
548
tumor marker for breast cancer
CA 15-3 | CA 27.29
549
clinical use for CA 15-3 and CA 27.29
stage disease monitor therapy detect recurrence
550
clinical significance of increased CA 15-3, CA 27.29
tumors other cancers non-cancerous conditions
551
tumor marker for pancreatic cancer
CA 19-9
552
clinical use for CA 19-9
stage disease monitor therapy detect recurrence
553
clinical significance of increased CA 19-9
pancreatic cancer other cancers non-cancerous conditions
554
tumor marker for ovarian cancer
CA 125
555
clinical use of CA 125
aid diagnosis monitor therapy detect recurrence
556
clinical significance of increased CA 125
ovarian cancer other cancers gynecological conditions
557
tumor marker for colorectal cancer
carcinoembryonic antigen (CEA)
558
clinical use of CEA
monitor therapy | detect recurrence
559
clinical significance of increased CEA
colorectal cancer other cancers non-cancerous conditions smokers
560
tumor marker for ovarian and testicular cancer; and marker for gestational trophoblastic diseases
human chorionic gonadotropin (hCG)
561
clinical significance of increased hCG
pregnancy ovarian cancer testicular cancer gestational trophoblastic diseases
562
clinical use of hCG
aid diagnosis monitor therapy detect recurrence
563
tumor marker for prostate cancer
prostate-specific antigen (PSA)
564
clinical use for PSA
screening aid diagnosis monitor therapy detect recurrence
565
Can men have increased PSA but not have prostate cancer?
yes
566
tumor marker for thyroid cancer
thyroglobulin
567
clinical use for PSA
monitor therapy | detect recurrence
568
clinical significance of increased PSA
prostate cancer | non-cancerous conditions
569
clinical significance of increased thyroglobulin
thyroid cancer | other thyroid disease
570
What should be measured at the same time as thyroglobulin?
antithyroglobulin antibodies
571
-Log[H+] or log (1/[H+])
pH
572
chemical that can yield H+; proton donor; pH <7
acid
573
chemical that can accept H+ or yield OH-; pH >7
base
574
weak acid and its salt or conjugate base; minimizes changes in pH
buffer
575
most important buffer for maintaining blood pH
bicarbonate/carbonic acid
576
Are phosphates a buffer?
yes
577
Are proteins a buffer?
yes
578
Is hemoglobin considered a buffer?
yes
579
second largest fraction of anions; HCO3-; proton acceptor or base
bicarbonate
580
What is bicarbonate regulated by?
kidneys
581
____ minus ____ = bicarbonate
CO2 minus 1
582
proton donor or weak acid; H2CO3
carbonic acid
583
What is carbonic acid regulated by?
lungs
584
_____ x _____ = carbonic acid
PCO2 x 0.03
585
total CO2
HCO3- + H2CO3 + dissolved CO2
586
partial pressure of CO2; directly related to the amount of dissolved CO2
Pco2
587
Henderson-Hasselbalch equation
pH = 6.1 + log ([HCO3-]/H2CO3]) or pH = 6.1 + log (HCO3-/PCO2) x 0.03
588
blood pH <7.38 | HCO3-:H2CO3 ratio decreased
acidosis (acidemia)
589
blood pH >7.42 | increased HCO3-:H2CO3 ratio
alkalosis (alkalemia)
590
decreased pH increased Pco2 normal HCO3-
respiratory acidosis
591
compensation for respiratory acidosis to re-establish 20:1 ratio
kidneys retain HCO3-; excrete H+
592
decreased pH normal Pco2 decreased HCO3-
metabolic acidosis
593
compensation for metabolic acidosis to re-establish 20:1 ratio
hyperventilation (blow off CO2)
594
increased pH decreased Pco2 normal HCO3-
respiratory alkalosis
595
compensation for respiratory alkalosis to re-establish 20:1 ratio
kidneys excrete HCO3-; retain H+
596
increased pH normal Pco2 increased HCO3-
metabolic alkalosis
597
compensation for metabolic alkalosis to re-establish 20:1 ratio
hypoventilation (retain CO2)
598
low oxygen content in arterial blood
hypoxemia
599
lack of oxygen at cellular level
hypoxia
600
barometric pressure x % gas concentration
partial pressure
601
osmolalitly normal range
275-295 Osm/kg
602
concentration of solute
osmolality
603
Which analytes contribute the most to osmolality?
electrolytes
604
clinical significance of increased osmolality
``` dehydration uremia uncontrolled diabetes alcohol intoxication salicylate intoxication ```
605
clinical significance of decreased osmolality
excessive water intake
606
normal range for osmolal gap
0-10 mOsm/kg
607
similar to anion gap but based on osmotically active solute concentration rather than concentration of ions
osmolal gap
608
clinical significance of >10 mOsm/kg
abnormal concentration of unmeasured substance (e.g., isopropanol, methanol, acetone, ethylene glycol_
609
Which calculated chemistry value is used in the diagnosis of poisonings?
osmolal gap
610
calculation for osmolal gap
measured osmolality minus calculated osmolality
611
normal range for urine-to-serum osmolality
1-3
612
calculation for urine-to-serum osmolality
urine osmolality divided by serum osmolality
613
Beer's Law: Concentration of unknown
(abs. of unknown/abs. of standard) x conc. of standard
614
A calcium is reported as 10 mg/dL. What is the concentration in mEq/L?
Atomic weight of calcium = 40 Valence of calcium = 2+ GEW = gram equivalent weight (gram molecular weight divided by valence) mEq/L = [(mg/dL)/GEW] x 10 mEq/L = [(10 x 10)/20) = 5
615
A calcium is reported as 10 mg/dL. What is the concentration in mmol/L?
Atomic weight of calcium = 40 Valence of calcium = 2+ GMW = gram molecular weight mmol/L = [(mg/dL)/GMW] x 10 mmol/L = [(10 x 10)/40] = 2.5
616
A calcium is reported as 5 mEq/L. What is the concentration in mmol/L?
mmol/L = [(mEq/L)/valence] mmol/L = 5/2 = 2.5
617
What is the molarity of a solution that contains 45 grams of NaCl per liter? (Atomic weights: NA = 23, Cl = 35.5)
Molarity (M) = grams per liter/GMW M = 45/58.5 = 0.77
618
What is the normality of a solution that contains 98 grams of N2SO4 per 500 mL? (Atomic weights: H=1, S=32, O = 16)
Normality (N) = grams per liter/GEW N = 196/49 = 4
619
What is the concentration in % of a solution that contains 8.5 grams of NaCl per liter?
(8.5 g/1000 mL) x (x/100 mL) 1000x = (8.5) x 100 x = 0.85%
620
What is the normality of a 3 M H2SO4 solution?
N = 3 x 2 = 6
621
What is the molarity of a 0.3 M H2SO4 solution?
M = 0.3/2 = 0.15
622
How many mL of 95% alcohol are needed to prepare 100 mL of 70% alcohol?
V1C1 = V2C2 | ``` x)(95) = (100)(70 x = 73.7 mL ```

AMT MLT Study Guide (3 decks)

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