1-6 Basic Lab Data

Question 1

Specificity

Answer 1

A measure of how well a test detects a disease without yielding a false + result. The probability that a test will be negative in the absence of a disease.

How accurately the test identifies people who DO NOT have a disease.

Question 2

What does a 100% specific test mean?

Answer 2

A 100% specific test only results in a positive result when the condition is present in the patient.

Question 3

Sensitivity

Answer 3

A measure of how well a test detects a disease without yielding a false negative result. The probability that the test will be sensitive in the presence of a disease.

How accurately the test identifies people who DO have a disease.

Question 4

What does a 100% sensitive test mean?

Answer 4

A 100% sensitive test reveals all patients with the tested-for condition. No test is 100% sensitive.

Question 5

Normal pH range

Answer 5

7.35-7.45

Question 6

Normal PaCO2 range

Answer 6

35-45

Question 7

Normal HCO3 range

Answer 7

22-26

Question 8

What are the main acid excreting organs?

Answer 8

Lungs and Kidneys

Question 9

What is the peak increase of PCO2? And why?

Answer 9

55. An end tital of 55 COULD be what the patient needs. If it gets over that, it becomes officially not good and we need to do something about it.

Question 10

What is the primary imbalance in a respiratory acidosis and alkalosis

Answer 10

CO2

Question 11

What is the primary imbalance in a metabolic acidosis or alkalosis

Answer 11

HCO3

Question 12

Base excess range

Answer 12

-3 - +3

Question 13

PaO2 Range

Answer 13

80-100 mmHg

Question 14

SaO2 Range

Answer 14

90-100 %

Question 15

What does the PaCO2 tell us?

Answer 15

ventilatory status

Question 16

What is base excess/deficit?

Answer 16

The amount of base or acid required to titrate the pH of one liter of blood to normal pH. Used for METABOLIC acid/base disorders.

Question 17

What does a negative base deficit mean? What does a positive base excess mean?

Answer 17

Negative base deficit: indicates the patient has a metabolic acidosis
Positive base excess: indicates the patient has a metabolic acidosis.

Question 18

What happens when base excess goes above +3 or below -3?

Answer 18

The patient becomes more unstable. BE x 10 = the % failure of the pt’s current care.

Question 19

Understand the difference between PaO2 and SaO2.

Answer 19

PaO2- the partial pressure of oxygen dissolved in the blood (if this value is less than 60, the pt WILL desat when the vent is disconnected)
SaO2- how much oxygen is bound to hemoglobin

Question 20

For every 10 mmHg change in PCO2

Answer 20

the pH will change 0.08 in the opposite direction

Question 21

For every 10 mEq change in HCO3

Answer 21

the pH will change 0.15 in the same direction

Question 22

What causes a high O2 affinity?

Answer 22

LOW- O2, CO2, 2,3-DPG, temp
HIGH- pH

Question 23

What does a CBC consist of?

Answer 23

WBC
WBC differential
RBC
Hgb
Hct
Platelet count

Question 24

What does a left shift in neutrophils indicate and why?

Answer 24

A left shift is seen as an increase in the number of bands and is common in infections.
immature neutrophils = active infection (which produces a left shift)

Question 25

A catecholamine dump is associated with an increase in what type of WBC?

Answer 25

Eosinophils

Question 26

What type of WBC causes pyrogenesis?

Answer 26

Monocytes

Question 27

What are the two types of lymphocytes, what response do they typically mitigate, and where do they mature?

Answer 27

B-type mature in the bone marrow, deal with bacterial. T-type mature in the thymus and deal with tumors or viruses.

Question 28

What does the hematocrit measure?

Answer 28

the volume of RBCs found in 100 mL of blood and expressed as a percentage.

Question 29

Less than what platelet count is associated with risk of bleeding?

Answer 29

150,000

Question 30

Normal sodium range

Answer 30

135-145

Question 31

Where will the fluid go if there is elevated vs low Na

Answer 31

Low Na = fluid will move from the blood into the tissues. High Na = fluid is drawn out of the tissues and moves into the blood. High risk of spontaneous head bleeds with this one.

Question 32

Normal K+ value

Answer 32

3.5-5

Question 33

What should you suspect if you see a sine wave on the ekg?

Answer 33

"v-tach" at less than 120 is most likely hyperkalemia

Question 34

What is the relationship between K+ and pH?

Answer 34

Inverse. acidic patient = k+ comes out of the cell basic patient = potassium is pushed into the cell

Question 35

What is the threshold for treating hypoglycemia in neonates and infants/children

Answer 35

Neonates: < 40 Infants: < 60

Question 36

BUN is a metabolic by-product from the breakdown of what?

Answer 36

blood, muscle, protein

Question 37

Tell me about the sensitivity and specificity of BUN for kidney failure

Answer 37

high sensitivity and lower specificity

Question 38

Creatinine is a metabolic by-product from the breakdown of what?

Answer 38

protein

Question 39

Tell me about the sensitivity and specificity of creatinine for kidney failure

Answer 39

high specificity and lower sensitivity

Question 40

What is albumin and what does it do?

Answer 40

Albumin is a plasma protein made by the liver. Water follows albumin, so it regulates osmotic pressure (fluid balance).

Question 41

Elevated liver enzymes indicate ______

Answer 41

liver damage/infection

Question 42

How is bilirubin created and what does a high level indicate?

Answer 42

bilirubin is created when RBCs are broken down and recycled. A high level can indicate hemolytic anemia, liver damage, blockage of the portal vein, or gallbladder disease.

Question 43

The liver converts ammonia to what?

Answer 43

urea

Question 44

What is the most common reason for elevated lactic acid levels?

Answer 44

Sepsis

Question 45

What does a high serum osmolarity mean? What does a low serum osmolarity mean?

Answer 45

high means that the blood is very concentrated, so fluid will be shifting from the tissues and into the blood. low means that the blood is very dilute and fluid will be shifting from the blood and into the tissues.

Question 46

Prothrombin time (PT) measures the efficacy of ______

Answer 46

coumadin-type anticoagulants

Question 47

Partial thromboplastin time (PTT) measures the efficacy of ______

Answer 47

intrinsic clotting factors, HEPARIN

Question 48

International normalized ratio (INR) compares ____ How do you interpret the value?

Answer 48

the patient : standardized control If a person is not on coagulation therapy, the patient and control will be the same, resulting in an INR of 1.

Question 49

What should the INR be for a patient who is receiving warfarin therapy?

Answer 49

2-3

Question 50

What does a high vs normal D-dimer mean?

Answer 50

High = pt is making extra clots (DVTs, PEs) Normal = pt is not making extra clots

Question 51

What is the most specific blood test for an acute MI

Answer 51

Cardiac-specific troponin (normal value 0.0 - < 0.50 mg/mL

Question 52

What is the hormone produced by the ventricles when they are stretched? What can it indicate?

Answer 52

B-type natriuretic peptide (BNP). High levels can indicate CHF (LV) or PE (RV).

Question 53

What is the order UMBC wants us to interpret ABGs?

Answer 53

1. check the pH 2. check the PaCO2 3. check HCO3 4. is it ROme or roME (resp or met) 5. check PaO2 6. check anion gap (when an acidosis)

Question 54

How well the test can RULE OUT a condition

Answer 54

specificity

Question 55

How well can the test FIND a condition

Answer 55

sensitivity

Question 56

Which system acid/base abnormality is associated with changes in the base excess?

Answer 56

Metabolic

Question 57

What are the conditions that can cause a left shift in the oxyhemoglobin dissociation curve?

Answer 57

INCREASED AFFINITY FOR 02 decreased temp decreased 2,3-DPG decreased PCO2 decreased PCO2 increased pH

Question 58

What are the conditions that can cause a right shift in the oxyhemoglobin dissociation curve?

Answer 58

DECREASED AFFINITY FOR 02 increased temp increased 2,3-DPG increased PCO2 increased PCO2 decreased pH

Question 59

Are platelets low or high in DIC?

Answer 59

low