ILA Flashcards
Describe the structure of an atherosclerotic plaque
- Found at bifurcation points
- Lipid necrotic core
connective tissue
smooth muscle
Fibrous cap
Modifiable RF for atheroscleosis
High cholesterol
Smoking
HTN - shearing forces damage endothelium and increase permeability to LDLs
High cholesterol - More LDL deposited = more foam cells
BMI
Diabetes (Type 2)
Sedentary lifestyle
Atherosclerosis non modifiable
Family hx -> Genetic component of DM,HTN Male Gender Age Ethnicity
How does smoking increase the risk of atherosclerosis
- free radicals in smoke damage endothelium
- CO and nicotine oxidise LDL
- Makes blood thicker so more easier to clot
Secondary prevention for atherosclerosis
Asprin - low dose (75mg)
Anti-HTN medication
Statins - reduce cholesterol levels
DM –> Meteformin
Define anaphalaxis
Severe life threatening generalised systemic hypersensitivity reaction
Describe beta adrenergic receptor activity of adrenaline
Stimulation of Beta-1 adrenoceptors
+ Ionotropic
+chronotropic
Bronchodilation - Beta-2
why might a second dose of adrenaline be required if sx do not respond or get worse
adrenaline has a short half life
Tx for anaphalaxis
Remove percipitating cause - Lie flat and raise legs - 500micrograms of adrenaline (IM) if no change repeat 5mins later - High flow o2 increases alveolar o2 conc to overcome hypoxia due to bronchospasm and interstitial oedema -Fluids Help restore circulation volume --> Increase SV--> Increase CO - Chlorphenamine - (Antihistamine) Blocks histamine-1 receptor - Hydrocortisone
A-O-F-C-H
Blood test for anaphalaxis
Blood test - Mast cell tryptase
Histamine effects in anaphalaxis
- Vasodilation and increased vascular permeability
- Angio-oedema and erythema to local tissues causing swelling
Why during anaphalaxis does a patients have:
- Raises HR
- Low BP
- Slow capillary refill time
Vasodilation increases vascular permeability –> oedema
- less fluid in vessels –> LOW BP
- Heart compensated for low bp by increasing HR
Anaphalaxis explain:
Raised resp rate
low o2 saturation
expiratory wheeze
Contraction of resp SM around trachea causes airway restricition
Anaphalaxis:
cells involved
Ab
Mediator of blood pressure
Mast cells
IgE
Histamine
Immediate treatment for anaphalaxis
ABCDE
Adrenaline
O2
Inorder to induce anasthesia quickly what properties hsould a drug have in terms of its protein binding and lipid solubility
LOW protein binding
- Lowers free conc of drug
HIGH lipid solubility
- Readily crosses BBB
Name 4 drug targets
Receptors
Ion channels
enzymes
Transporters
Define bioavailabilty
The amount of a drug that reaches circulation after first pass metabolism is complete
Explain Morphines bioavailability
Oral - 50% bioavailability
IV - 100%
Oral dose of morphine has to be double that of IV
What do you do if a patient with renal failure is to be given morphine
- Lowe dose for longer intervals Morphine metabolised in to Morphine 6 glucoronide More potent Morphine is excreted via the kidneys Kidney failure --> Not readily excreted
Explain the difference in presentation between an arterial thrombus and a venous thrombus
Arterial
- Lack of pulse
- Pale skin
- Coldness to the touch
Venous
- Red
- Hot
- Still have a pulse
Virchows triad
Hypercoaguability
Endothelial injury
Blood flow stasis
Test for DVT
D-Dimer
- Fibrin degredation products
- Present after DVT/PE
- Positive does not mean Dx
Heparin MOA
UF - Binds to antithrombin increasing its ability to inhibit Thrombin, Factor Xa ans IXa
Monitor and adjust dose with - APTT
Acts on extrinsic pathway
LMWH - Enoxaparin
Inactivates factor Xa - but not thrombin
Accumulates in renal failure
