Exam 2: L6 Lab Analysis

Question 1

1. List and correlate preanalytic variables with Clinical scenarios, including timed tests and variables associated with:
   a. Time

Answer 1

i. Circadian rhythm-diurnal variation
ii. Rhythms less than or greater than 1 day
iii. Timed tests-meals (glucose, triglycerides), drugs.

Question 2

b. tobacco use

Answer 2

i. increased:glucose, catecholamines, cortisol, FFAs
ii. increased-WBCs, carcinoembryonic antigen (CEA), carboxyhemoglobin-carbon monoxide content.
iii. Increased hemoglobin.

Question 3

c. alcohol use

Answer 3

i. increased triglycerides
ii. GGT
1. Induction in moderate and heavy drinkers
iii. Caffeine-increased catecholamines, glucose
1. Elevated lipids with chronic consumption

Question 4

d. Age

Answer 4

i. Elderly
1. Decreased protein-Albumin
2. Decreased Creatinine-lower muscle mass
3. Decreased muscle-related enzymes
4. Decreased lymphocytes
ii. Children
1. Lymphocytes must exceed 2500 (adult-1500)
2. Alkaline phosphatase (enzyme product of osteoblasts)

Question 5

e. Gender

Answer 5

1. lower Hgb, ferritin, iron
   a. Go to male levels at menopause
2. Smaller muscle-lower creatinine, BUN, AST, CK, other.

Question 6

f. Exercise

Answer 6

i. Strenuous exercise-muscle enzymes, lactic acid elevated
ii. Well trained-lower hemoglobin, glucose, WBCs
1. Increased basal levels of muscle enzymes.
2. Higher bilirubin (many athletes are normally anemic-don’t need as much blood, repetitive action traumatized blood vessels and breaks down red blood cells)

Question 7

2. Define the references interval/normal value.

Answer 7

a. Reference interval-expected “normal” result in healthy individual.
i. 2 SD from mean-95%

Question 8

a. Accuracy

Answer 8

reliability of a test method

Question 9

b. Precision

Answer 9

reproducibility of a result

Question 10

c. Gold standard

Answer 10

recognized methodology against which new tests are compared.

Question 11

d. Sensitivity

Answer 11

number positive test result who are known to have disease/condition.

Question 12

e. Specificity

Answer 12

number with negative test result without the disease.

Question 13

f. PPV

Answer 13

frequency in which positive test correlate with patient having disease.

Question 14

g. NPV

Answer 14

percent of negative test results that are truly negative.

Question 15

a. BUN-produced in liver from breakdown of AA-derived ammonia.

Answer 15

i. Excreted by kidneys.
ii. Increased BUN-all renal disease, poor renal perfusion
1. Nonrenal causes-catabolism (fever, burn, diabetes, exercise), GI bleed.
iii. Decreased Serum Level –
1. Low protein diet
2. Pathologically decreased-advanced liver disease.

Question 16

b. Creatinine-end product of creatinine in skeletal muscle-yielded ATP

Answer 16

i. Constant and proportional to muscle mass
ii. Excreted by kidney
iii. Elevated-renal disease, poor renal perfusion, dehydration
1. Insensitive but specific.

Question 17

c. Bilirubin-degradation of hemoglobin

Answer 17

i. Jaundice
1. Pre-hepatic-hemolysis
2. Intrahepatic-liver disease
3. Posthepatic-gallstone

Question 18

a. Alkaline phosphatase-hydrolase

Answer 18

i. Liver (biliary), bone (osteoblasts), placenta, other: intestine, some cancer

Question 19

b. Lactate Dehydrogenase-glycolytic pathway

Answer 19

i. Wide distribution-elevated with nonspecific tissue damage.
ii. Elevated-small amounts of tissue injury
iii. High plasma levels-breakdown of erythrocytes

Question 20

c. Transaminases/Aminotransferases

Answer 20

i. AST
1. Wide distribution-mitochondrial and cytoplasmic enzymes.
2. High in hepatocytes, released in injury
3. Commonly elevated in cardiac, skeletal muscle injury
ii. ALT-LIVER

Question 21

6. What labs are used to confirm a diagnosis of myocardial injury?

Answer 21

a. CK-MB
i. Elevated 6 Hours post MI
b. Myoglobin – Non-specific indicator of MI
c. Troponin I (and T)
i. High sensitivity and specificity
ii. Remains Elevated 1 week

Question 22

a. Liver Function Tests

Answer 22

i. Transaminases/aminotransferases
1. AST, ALT
ii. Alkaline phosphatase
iii. GGT
iv. LDH

Question 23

b. Muscle disease

Answer 23

i. CK, AST, LD, Aldolase, nonenzyme proteins:myoglobin

Question 24

c. Bone disease

Answer 24

alkaline phosphatase

Question 25

What is the significance of alterations in gamma globulins?

Answer 25

a. Gamma globulins-from plasma cells. b. From problems with B lymphocytes or plasma cells i. Polyclonal gammapathy-prolonged infection or inflammation ii. Monoclonal gammapathy-neoplastic (of plasma cells).

Question 26

9. When is albumin decreased? What are causes of increased albumin?

Answer 26

a. Decreased i. Impaired synthesis-Malnutrition, malabsorption, hepatic dysfunction ii. Increased loss-renal disease, protein-losing gastroenteropathy, ascites b. Increased i. Dehydration ii. Artifact-tourniquet on too long.

Question 27

10. What are associations with alpha 1-globulins; alpha2-globulins?

Answer 27

a. Alpha-1 globulins-alpha-1 antitrypsin is major component i. Protease inhibitor (counters leukocyte elastase) ii. Acute phase reactant iii. Deficiency: 1. Pulmonary emphysema, cirrhosis of liver. b. alpha-2 globulins-includes “acute phase reactants” i. alpha-2-macroglobulin-kinin inhibitor ii. haptoglobulin-carrier of free hemoglobin

Question 28

What is the significance of elevated CRP, ESR?

Answer 28

c. CRP i. Fastest rising acute phase reactant ii. Presence of bacterial infection iii. Inflammatory response to autoimmunity iv. Predictive for cardiovascular event. d. ESR i. Length of fall of RBS in column of blood ii. Increased globulins, fibrinogen. Decreased albumin favor accelerated sedimentation 1. Increased ESR-nonspecific indicator of inflammation.