module 4 lab interpretation Flashcards
1
Q
when should laboratory tests only be ordered?
A
If the results of the test will affect decisions about the patient care.
The serum, urine, and other body fluids can be analyzed routinely.
2
Q
name the divisions of clinical microbiology
A
Has several different sciences: bacteriology,virology,parasitology,immunology, andmycology.
3
Q
name the divisions of clinical chemistry
A
This area includes analysis of blood specimens, including tests related to enzymology,toxicologyandendocrinology
4
Q
name the divisions of hematology
A
This area includes analysis of blood cells. It also often includescoagulation.
5
Q
name the divisions of blood bank
A
Involves the testing of blood specimens in order to provide blood transfusion and related services.
6
Q
name the divisions of DNA diagnostics
A
DNA testing may be done here, along with a subspecialty known ascytogenetics.
7
Q
give an example of Improper handling or processing in the lab
A
hyperkalemia due to hydrolysis of blood specimen
8
Q
give an example incorrect sampling timing
A
fasting BG level taken shortly after a meal
9
Q
give an example of Incomplete Collection
A
24 hrs urine collection that does not span a full 24 hrs
10
Q
meat ingestion can cause a false-positive _________.
A
guaiac test
11
Q
cardioversion leads to increased levels of _________.
A
creatinine kinase
12
Q
what leads to Increased Hemoglobin
A
polycythemia vera copd vigourous exercise residents at high altitudes chronic smokers
13
Q
what leads to decreased hemoglobin
A
anemia blood loss hemolysis fluid replacement pregnancy
14
Q
give another name for hematocrit
A
packed cell volume
15
Q
define hematocrit
A
Volume of blood that is occupied by RBCs.
It is expressed as a percentage of total blood volume.
16
Q
reasons for decreased hct are all except
a. dehydration and shock
b. cirrhosis
c. hyperthyroidism
d. leukemia
A
a. dehydration and shock
17
Q
which of the following leads to increased RBCs
a. cirrhosis
b. polcythemia vera
c. copd
A
b. polcythemia vera
18
Q
The higher the MCV, _____________________________.
A
the larger the average size of the RBC.
19
Q
what kind of deficiency causes increased MCV? ie marocytic RBCs
A
folate deficiency and vitamin b12 deficiency
20
Q
which medications lead to macrocytic RBCs
A
valproic acid, zidovudine, antimetabolites (methotrexate)
21
Q
what kind of deficiency causes decreased MCV? ie microcytic RBCs
A
iron deficiency anemia
22
Q
what is the cause for normochromic normocytic anemias
A
blood loss, hemolysis
23
Q
what is the cause for hypochromic microcytic anemias
A
iron deficiency
24
Q
what is the cause for normochromic macrocytic
A
folate deficiency and vitamin b12 deficiency
25
low ferritin may be a sign of _________ deficiency.
iron deficiency
26
reasons for Increased Reticulocytes
Hemolytic anemia
Hemorrhage
Sickle cell disease.
Indicative of response to treatment of anemias secondary to iron, vitamin b12, or folate deficiency.
27
reasons for decreased reticulocytes
```
Infection
Alcoholism
Renal disease (from decreased erythropoietin)
Toxins
Untreated iron deficiency anemia
Drug-induced bone marrow suppression.
```
28
causes of Increased WBCs (leukocytosis)
Infection, leukemia, trauma, thyroid storm, and corticosteroid use. Emotion, stress, and seizures
29
causes of decreased WBCs (leukopenia)
Viral infection, aplastic anemia
| In bone marrow depression caused by the use of chemotherapy or immunosuppressants
30
when do false elevations in hgb and MCH occur
when WBCs count > 50,000 cells/mm3
31
nuetrophils are involved in the pathogenesis of inflammatory disorders such as
RA and IBD
32
what are bands
bands are immature neutrophils
33
the use of which medications increase neutrophils
corticosteroids
34
Decreased neutrophils is due to
Viral infections (eg, mononucleosis, hepatitis),
Septicemia (blood poisoning by bacteria)
Use of chemotherapy drugs.
35
what is ANC
absolute neutrophil count
| total number of circulating segs and bands
36
risk of diseases increases as ANC __________.
decreases
37
what is the main function of lymphocytes
antigen recognition and immune response
38
reasons for Increased Lymphocytes (Lymphocytosis)
| I perceive this major clash in infectious viral pneumonia
```
Influenza
Pertussis
Tuberculosis
Mumps
Cytomegalovirus Infection
Infectious Mononucleosis
Infectious Hepatitis
Viral pneumonia
```
39
reasons for Decreased Lymphocytes
| A burden at Bombay airforce station noted mmg
```
Acute infections
Burns
AIDS
Bone Marrow suppression
Aplastic Anemia
Steroids
Neurologic Disorders
Multiple Sclerosis
Myasthenia Gravis
Guillian Barre Syndrome
```
40
where do eosinophils reside
in the intestinal mucosa and lungs
41
why must the eosinophil count be taken daily
due to diurnal variation
42
reasons for decreased eosinophils
Commonly attributed to an increase in adrenal steroid production
43
Increased Eosinophils (eosinophilia)
```
Allergic disorders
Collagen vascular disease
Parasitic infections
Immunodeficiency disorders
Some malignancies.
```
44
Increased Monocytes (monocytosis)
May be observed in the recovery phase of some infections e.g. subacute bacterial endocarditis, TB, Syphilis, Malaria
Leukemia & lymphoma.
45
Decreased Monocytes (monocytopenia)
bone marrow suppressive agents or severe stress
46
Increased basophils (basophilia)
Increased basophils (basophilia)
May be seen in hypersensitivity reactions to food or medications
Certain leukemias
Polycythemia Vera.
47
Marked leukocytosis is usually due to increased _________ or ________.
neutrophils or lymphocytes
48
risk of bleeding is low unless platelet count falls below __________.
50,000 cells/ microL
49
Increased Platelets (thrombocytosis, thrombocythemia)
Infection, malignancies, splenectomy
Chronic inflammatory disorders e.g. RA
Polycythemia vera, hemorrhage, iron deficiency anemia, or myeloid metaplasia.
50
Decreased Platelets (thrombocytopenia)
May occur in autoimmune disorders such as idiopathic thrombocytopenic purpura
With aplastic anemia, radiation, chemotherapy
Bacterial or viral infections
Drugs e.g. heparin, valproic acid.
51
Microscopy
For direct detection of parasites & some fungi
52
Electron microscopy
Detection of viruses
53
Culture & sensitivity
For bacteria
| Can be done for almost any body fluid or tissue
54
Antigen detection (Serology)
e.g. HBsAg (hepatitis B surface antigen)
55
Molecular biology assays (Molecular diagnostics)
Most commonly used is Polymerase Chain Reaction (PCR) to detect DNA / RNA of viruses and bacteria
56
Viral Load Tests
Measures the amount of virus in the sample.
57
Alpha-fetoprotein (AFP)
May be raised in various cancers (liver, germ cell testicular cancers, bowel, stomach, lung, breast, lymphoma)
Non-cancerous conditions (e.g. chronic hepatitis, cirrhosis)
58
Carbohydrate antigen 125 (CA 125)
May be raised in many gynaecological conditions e.g. benign ovarian cysts, endometriosis, pregnancy & ovarian cancer.
59
Lactate dehydrogenase (LDH)
Levels can be raised for a variety of reasons where cellular destruction is present (e.g. lymphoma, pancreatitis, liver and kidney disease)
60
Carcinoembryonic antigen (CEA)
The preferred marker to monitor patients with colorectal cancer during treatment, but it is not useful for screening or diagnostic
Can also be raised in cancer of lung, breast, thyroid, pancreas, liver, stomach, ovary and bladder.
non-cancerous diseases and smoking might increase it
61
Prostate-specific antigen (PSA)
Specific tumour for prostate cancer & used for screening
| level can also be raised in patients with BPH, elderly men and those with larger prostates.
62
give examples of detection of recurrent cancer with tumor markers.
PSA (for prostate cancer) and CA 125 (for epithelial ovarian cancer)
63
what is the main indicator for SLE
ANA
64
apart from SLE ANA may be positive in
```
RA
sjorgens syndrome
mixed connective tissue disease
polymyositis
scleroderma
autoimmune liver disease
```
65
RF is a diagnostic indicator for?
RA
66
Conditions, other than RA, with a high levels of RF are:
```
SLE
other connective tissue diseases
chronic inflammatory/ infectious disorders
malignancy
sjorgens syndrome
```
67
Chronic inflammatory diseases such as ______and ______ can be monitored using serial CRPs.
SLE & RA
68
what does CRP monitor. how long does it take to rise and how many days does it take to resolve.
Monitors the presence, intensity, and recovery of inflammatory process.
CRP is the most useful of the acute phase inflammation
CRP rises sharply 4–8 hrs after tissue damage by infection, inflammation or trauma & returns to normal 2–3 days after disease activity stops
69
which is a more useful marker for inflammatory disorder
a. CRP
b. ESR
a. CRP
70
what is Erythrocyte Sedimentation Rate (ESR)
a measure of how quickly RBCs settle in a tube of blood
71
ESR is a non specific indicator of?
inflammatory disease and protein abnormalities
72
why is ESR not very effective for diagnosis
In an acute illness, the ESR may take a week or more to start to rise and stay elevated for some weeks after its resolution in contrast to other markers.
73
define anion gap
it is reflective of the unmeasured anions and cations in serum
74
what does an increase in anion gap suggest? what is it indicative of?
An increase in anion gap suggests an increase in the number of negatively charged weak acids in the plasma.
High anion gap is an indication of metabolic acidosis
75
name some conditions that may cause high anion gap
ketoacidosis, renal failure, salicylate, methanol and ethylene glycol toxicity.
76
formula or calculating anion gap
Na+ - [Cl- + HCO3-]
77
what happens in metabolic acidosis
arterial ph decreases, bicarbonate decreases, paco2 decreases
78
what happens in respiratory acidosis
arterial ph decreases, paco2 increases, bicarbonate increases
79
what happens in metabolic alkalosis
arterial ph increases, bicarbonate increases, paco2 increases
80
what happens in respiratory alkalosis
arterial ph increases, paco2 decreases, bicarbonate decreases
81
to protect body proteins acid base balance must be controlled within the extracellular ph __________ and intracelluar ph of _______.
pH of 7.35 - 7.45
| pH of 7.0 - 7.3.
82
The body’s principal buffer system is the __________________________.
carbonic acid/bicarbonate (H2CO3/ HCO3−) system.
83
```
Severe acid–base disorders can affect multiple organ systems:
Cardiovascular
Pulmonary
Renal
Neurologic
```
Cardiovascular: it might cause impaired contractility leading to arrhythmias
Pulmonary: it might cause impaired oxygen delivery leading to respiratory muscle fatigue & dyspnea
Renal: it might cause hypokalemia & nephrolithiasis
Neurologic: it might cause decreased cerebral blood flow leading to seizures & coma.
84
a CK-MB level of _____________ is indicative of MI
greater than 4-8%
85
CK-MB takes _______ to rise and returns to normal is ________.
4-8 hours to rise
| 2-3 days
86
CK-MB peaks between _______.
12-24 hours
87
What are the sensitive markers of cardiac injury
troponin I and troponin T
88
troponin Rise within __________________.
Levels should be drawn on _________ and ______________.
4 hours of onset of chest pain.
| admission and 8 - 12 hours thereafter.
89
Approximately_____of patients with no elevation in CK-MB may demonstrate elevated troponin and thus may be diagnosed with a___________.
30%
| non-Q-wave MI.
90
what is PT
PT is a blood test that measures how long it takes for the blood to clot
PT is the time needed to convert prothrombin to thrombin.
91
the action of PT depends on
Its action depends on adequate Vitamin K intake and absorption
92
name drugs that increase TSH
metoclopromaide and dooamine antagonists
93
which medications decrease TSH
Medications with dopaminergic activity (e.g. dopamine, levodopa, and glucocorticoids) can decrease TSH levels.
94
reasons for increased T4 hyperthyroidism
Pregnancy
Hepatitis
Medications: Estrogen Replacement Therapy, Oral Contraceptives, Tamoxifen, And Raloxifene.
95
decreased T4 (hypothyroidism)
Renal failure
Malnutrition
Liver disease
Medications that compete for T4 binding proteins (e.g. salicylates).
Medications that increase the clearance of T4 (e.g. phenytoin, phenobarbital, and carbamazepine)
96
Why is free T4 a better indicator of thyroid function
Free T4 is a more accurate reflection of clinical thyroid status because Total T4 levels can be affected by conditions that alter the amount of thyroxine binding proteins.
97
free T4 may be increased or decreased by ______,______ and _______.
amiodarone, iodides, and lithium
98
Increased T3
```
Hyperthyroidism
Thyrotoxicosis (Graves' Disease)
With High Doses Of Levothyroxine
Pregnancy
Use Of Estrogens or Oral Contraceptives
```
99
Decreased T3
Hypothyroidism
Malnutrition
Anorexia
Corticosteroids and Propranolol decrease conversion of T4 to T3 (hence may result in reduced T3)
100
High serum ALT concentrations are indicative of
hepatocellular disease e.g. hepatitis, alcoholic liver disease, mononucleosis, and cholestasis.
101
medications causing elevation in ALT
HMG-CoA Reductase inhibitors, phenytoin, and valproic acid.
102
______ is a marker of liver disease.
ALT
103
which is a more specific marker of liver disease ALT or AST
ALT
104
In alcoholic liver disease, the ratio of AST to ALT is usually _________.
greater than 2:1.
105
Elevations of AST may also be seen with drugs like?
paracetamol and methyldopa
106
medications that cause false elevations in AST by interfering with assay
erythromycin, levodopa, tolbutamide
107
name drugs that increase GGT
Enzyme inducers such as phenobarbital, rifampin, phenytoin, carbamazepine, and ethanol may also increase GGT levels.
108
GGT is considered a sensitive marker of _____________.
Ethanol intake.
109
An elevated GGT associated with an increased ALP suggests ?
a hepatic source for the abnormal ALP.
110
Jaundice occurs when total bilirubin exceeds _______.
2mg/dl
111
signs of hyperbilirubinemia apart from jaundice
scleral icterus and dark urine
112
name a class of drug that causes elevated bilirubin
antimalarials
113
causes of elevated bilirubin
```
Hemolysis
Pernicious anemia
Large hematomas
Gilbert syndrome
Elevated direct bilirubin may be associated with hepatocellular disease and cholestasis
Drugs e.g. Antimalarials
```
114
CHF causes hypoalbuminemia. t/f
true
