ILA/GP Flashcards
Tunica intima
Innermost layer of blood vessel
Endothelial cells
Smooth layer for seamless blood flow
Tunica media
Middle layer of blood vessel
- Smooth muscle cells = contract and relax.
- Elastic fibers = withstand pressure changes.
Tunica adventitia
Outermost layer of artery.
- Collagen and elastic fibers = support and structure.
- Vasa vasorum - network of small blood vessels that supply the outer layers of larger blood vessels.
- Anchors the vessel to the surrounding tissue.
Primary prevention for atherosclerosis?
- Cut alcohol - 14 units/ week for men and women
- Improve diet - reduce cholesterol
- Increase exercise - reduce weight
- Stop smoking
- Take prescribed medications
Secondary prevention for atherosclerosis?
- Manage diabetes risk —> review again
- Statins (side effects: muscle cramping)
- Low dose aspirin - 75mg - enough to inhibit platelet clotting (thrombus formation)
- Manage hypertension and other conditions
Define anaphylaxis
Severe, life-threatening, generalised or systemic hypersensitivity reaction.
Caused by asevere type 1 hypersensitivityreaction (IgE-mediated)
Stages/pathophysiology of anaphylaxis?
- Sensitisation phase - first encounter with allergen = IgE Abs produced by B cells
- Re-exposure: allergen binds to IgE Abs on mast cells + basophils.
=> production of histamine, tryptase, chymase, leukotrienes, interleukins and cytokines. - Histamine causes vasodilation = SHOCK
Signs and symptoms of anaphylaxis?
- Skin reactions (hives)
- Breathing difficulties
- Swelling
- Cardiovascular symptoms due to vasodilation = rapid, weak pulse + shock + prlonged cap refill time
- GI symptoms
- Neurological (disorientation, LOC)
Treatment for anaphylaxis?
- IM adrenaline (300 microgram EPIPEN or 500 micrograms in hospital)
- Repeat after 5 mins if required
- ABCDE
- High flow oxygen
- IV fluids
- IV antihistamines (for skin symptoms)
- Beta-agonists
Mode of action of adrenaline in treatment of anaphylaxis?
Activates sympathetic response
= B2 adrenoreceptors (bronchodilation) = A1 receptors (vasoconstriction to increase BP)
= B1 receptors (increased cardiac contractility)
Confirmatory blood test for anaphylaxis?
Tryptase (due to mast cell degranulation)
What characteristics should drug have to put patient to sleep quickly?
- Pass through cell membranes - lipophilic (lipid-soluble)
- Low protein binding - bioavailable - high amount of free drug
Oral bioavailability of morphine?
50%
Hence need double dose if given orally
What is the metabolite of morphine?
Morphine-6-glucoronoide
More potent than morphine - can cause toxicity in renal impairment
Metabolised by CYP2D6
Signs of ARTERIAL vs venous thrombosis?
ARTERIAL:
Peripheral vascular disease
6Ps
VENOUS:
DVT/PE
Virchow’s triad
6PS of arterial thrombosis?
Pulselessness
Pallor
Pain
Perishingly cold
Paralysis
Paraesthesia
Virchow’s triad?
- Stasis of blood flow - immobilisation - long haul flights etc
- Endothelial injury - i.e. smoking, cellulitis, AF, LV dysfunction
- Hyper-coagulability - i.e. dehydration, meds (oestrogen), polycythaemia, thrombocytosis, inflammation, IBD, autoimmune diseases, pregnancy, immobilisation, malignancies (esp. blood cancers), sickle cell anaemia, sepsis
Signs of venous thrombosis? DTV/PE
Unilateral swelling]
Oedema
Tender
Erythematous
Distension of superficial veins
Pre-renal causes of AKI?
Insufficient blood supply reduces filtration of blood
= dehydration, shock (i.e. sepsis, anaphylaxis, or acute blood loss), heart failure, renal artery stenosis, AF/arrhythmias, MI, diarrhoea, diuretics, burns
Complications of AKI?
- Chronic kidney disease
- Heart failure
- Hyperkalaemia
- Metabolic acidosis – which can cause nausea, vomiting, drowsiness and breathlessness
- Fluid overload - peripheral or pulmonary oedema
Renal causes of AKI?
Glomerulonephritis
Acute interstitial nephritis
Acute tubular necrosis
Haemolytic uraemic syndrome
Rhabdomyolysis
Post-renal causes of AKI?
- Kidney stones
- Tumours (retroperitoneal, bladder or prostate)
- Strictures of the ureters or urethra
- Benign prostatic hyperplasia
- UTIs
- Neurogenic bladder
Cushing’s triad?
Body response to raised ICP due to intracranial bleed (haemorrhagic stroke):
- Bradycardia
- Irregular respirations
- Hypertension
Causes of ischaemic stroke?
Blood supply to brain may be disrupted by:
- Thrombusorembolus
- Atherosclerosis
- Shock
- Vasculitis