Primary Revision Flashcards Preview

FRCA Final > Primary Revision > Flashcards

Flashcards in Primary Revision Deck (58):
1

Context sensitive half time

Time taken for the plasma concentration of a drug to fall to 50% after stopping that infusion

2

3 causes of calcified CXR lesions

Asbestosis Mitral valve disease Chicken Pox

3

Visual symptoms of papilledema

Visual obfuscations Enlargement of blind spot Blurring of vision

4

Mapleson A minimum flow (SV)

0.8-1x MV

5

Mapleson B minimum flow (SV)

1.5-2x MV

6

Mapleson C minimum flow (SV)

1.5-2x MV

7

Mapleson D minimum flow (SV)

2-3x MV

8

Mapleson E minimum flow (SV)

2-3x MV

9

Mapleson A minimum flow (MV)

2x MV

10

Lack system

co-axial Mapleson A

11

Bain system

co-axial Mapleson D

12

Bain system FGF is carried through...

The inner tube

13

Closing capacity = FRC when?

Age 44 supine Age 66 upright

14

Identify the structures of the descending tracts

Q image thumb

  1. Medial longitudinal fasciculus
  2. Lissaur's tract
  3. Lateral corticospinal Tract
  4. Rubrospinal tract
  5. Pontine reticulospinal tract
  6. Medullary reticulospional
  7. Lateral vestibulospinal
  8. Tectospinal
  9. Ventral corticospinal

 

A image thumb
15

Identify the structures of the ascending tracts

Q image thumb

  1. Fasciculus gracilis
  2. Fasciculus cuneatus
  3. Dorsal spinocerebellar tract
  4. Ventral spinocerebellar tract
  5. Spinothalamic tract

A image thumb
16

Anion Gap

[Na] + [K] - [HCO3] - [Cl]

Range 8 - 16 mEq/L

17

Causes of a high anion gap metabolic acidosis

  • High unmeasured anions
    • Lactic acidosis
    • DKA
    • Alcohol, Methanol, Ethelyne Glycol

18

Clearance

A measure of the body's ability to remove a drug. It is the volume of plasma, from which a drug is completely removed in a given time (mL/min). This is commonly indexed against body mass (mL/kg/min)

19

Clearance (formulas)

Cl = Vd / T and since T = 1 / K, Cl = K.Vd

20

Pharmacokinetics

  • Absorbtion
  • Distribution
  • Metabolsim
  • Excretion

21

Bioavailibility

The fraction of a drug availible to the systemic circulation compared with IV administration. Calculated by area under the curve.

22

1st Pass metabolism

Metabolism by the gut wall or liver prior to reaching systemic circulation. PR, SL, TD, Inhalational, IV etc. all bipass 1st pass metabolism

23

First Order Kinetics

Rate of elimination of a drug is directly propertional to drug concentration

24

Time to reach steady state (first order kinestics)

5 half lives

25

Elimination profile in a single compartment.

C = C0.e-kt

where:

  • C = concentration at time = t
  • C0 = concentration at time = 0
  • k = rate constant
  • t = time
  • -kt is a dimentionless term

26

Describe C0

The concentration of a drug at time = 0.

C0 = dose / Vd

27

Express C=C0e-kt logarhythmically

ln C = -kt ln C0

or

log C = (-kt/2.303) . log C0

28

What is the time constant (T)

The time taken for a drug to be completely eliminated, had the original rate of decline continued. The inverse of the rate constant.

29

What is the value of C at t = T

C = C0 - (e.C0)

i.e. C0 has fallen by a factor of e

30

Half life

The time taken for conentration to reach half its starting value

31

Relationship between half life and the time constant (T)

T½ = T.ln2

32

Which is bigger? the time constant or half life?

time constant > half life

ALWAYS

Since T½ = T.ln2 and ln2 < 1

33

Why do you wake up quickly following a propofol infusion at steady state?

Conductance between the peripheral and central compartments is low. The terminal elemination take a long time, but plasma concentrations fall rapidly and you wake

34

Michaelis constant

The concentration of a substrate at which an enzyme system is working at half its maximal capacity

35

What factors affect hepatic extraction of a drug

  1. Protein binding
  2. Blood flow
  3. Michaelis constant

36

Volume of Distribution

The apparent volume into which a drug disperses in order to produce the observed plasma concentrations.

Vd = Dose / C0

37

Seddon-Sunderland Classification

Classifcation of peripheral nerve injury

  1. Neuropraxia
  2. Axonotmesis
  3. Neurotmesis with preservation of perineurium
  4. Neurotmesis with preservation of epineurium
  5. Neurotmesis with complete transection of nerve trunk

38

Isomer

Molecules that have the same molecular formula but whose atoms are arranged differently

39

Structural Isomer

Molecules with the same molecular formula but different chemical structure

40

Colloid

A substance that has insoluble microscopic particles suspended within another medium, most commonly a liquid

41

Blood Gas Solubility Coefficient

The ratio of the amount of a substance in one phase to the amount in another phase, at a stated temperature, when both phases are in equilibrium and of equal volume and pressure

42

What is the embryological origin of the adrenal medulla?

Chromaffin cells derived from the ectodermal cells of the neural crest 

43

What is the embryological origin of the adrenal cortex?

Mesoderm

44

What does the adrenal cortex secrete?

  • Steroid hormones:
    • Glucocorticoids
    • Mineralocorticoids
    • Androgens

45

What are glucocorticoids?

Steroid hormones that affect the metabolism of carbohydrates, fats and proteins and are important in mediating the response to fasting and stress 

46

What are the primary effects of glucocorticoids?

  • Liver
    • Protein catabolism
    • Gluconeogenesis
  • Cardiovascular
    • Maintenance of response to catecholamines
  • Kidney
    • Weak mineralocorticoid activity
  • Immune
    • Immunosuppresion
    • Slowed healing

47

What are the primary effects of mineralocorticoids?

  • Liver - none
  • Cardiovascular - none
  • Kidney
    • Resorbs Na+ in the Distal Convoluted Tubule at the expense of loss of K+ and H+ lost into the urine
    • Expantion of the intravasular compartment
  • Immune - none

48

What factors control the release of Aldosterone?

Aldosterone is released in response to:

  • Decreased Na
  • Decreased plasma volume
  • Increased K
  • Activation of the Renin-Angiotensin System

The final common pathway is the binding of angiotensin-II to receptors in the zona glomerulosa. This acts via G-protein to activate phospholipase-C. It facilitates the conversion of corticosterone to aldosterone.

49

What is Hyperaldosteronism?

Excess circulating aldosterone:

  • Primary
    • Conn's Syndrome - adrenal adenoma (60%)
    • Bilateral adrenal hyperplasia (30%)
    • Carcinoma
  • Secondary
    • Increased activation of the R-A-A system e.g. CCF or liver cirrosis

50

What are the core features of hyperaldosteronism?

  • Hypertension
  • Hypokalaemia
  • Metabolic alkalosis

51

What is SVR?

80 x (MAP - CVP)/CO = 1000 - 1500 dyne/s/cm5

52

What factors cause a right shift of the oxyhaemaglobin dissociation curve?

Think about which factors require or result in increased oxygen delivery in tissues.

  • Increased temperature
  • Reduced pH
  • Raised PaCO2
  • Raised 2,3 DPG
  • Pregnancy
  • Anaemia
  • Post-acclimatisation at altitude

53

Which components in PRC help prevent depletion of 2,3-DPG?

  • Phosphate
  • Adenosine
  • Glucose

NB, mannitol helps prevent oxidative stress to RBC, but has no impact upon 2,3-DPG

54

What are the "classical" anti-inflammatory cytokines?

  • IL4
  • IL-10
  • IL-13
  • IFN-alpha
  • Transforming growth factor-beta

55

Define Osmolarity

Osmolarity refers to the number of osmoles per litre of specific solvent

56

Define osmolality

Osmolality refers to the number of osmoles per kg of specific solvent

57

Maximum concentrating capacity of the kidneys

1200-1400 mOsm.L-1

58

Minimum mandatory renal solute excretion

800 mOsm/day