Haematology (clotting) Conditions, Signs, Causes And Differentials Flashcards
What are the warning signs of the presence of a bleeding disorder?
(e.g. as a parent might notice comparing their child to another)
- Bleeds longer (Tend to ooze for longer)
- Bleeds more freely
- Bleeds easily
- Bruises easily
- Direct pressure on a wound doesn’t stop the flow easily
What are the differentials for a bruised non-ambulance child?
Deliberate abuse (until proven otherwise)
Bleeding disorder
What is haemophilia A?
An x-linked recessive condition causing deficiency of factor 8.
This means that the intrinsic pathway isn’t working. Clots still form but they rely only on the extrinsic pathway, which produces unstable clots that are dislodged easily.
Lots still
Grading depends on :
- level of factor present
- If bleeding is only on trauma, on small injury or spontaneously
- frequency; rarely, once per month, once or more per week
- site; rarely in joints, sometimes in joints, often in joints
Mild, moderate and severe
What haemophilia B?
An x-linked recessive condition causing deficiency of factor 9.
This means that the intrinsic pathway isn’t working. Clots still form but they rely only on the extrinsic pathway, which produces unstable clots that are dislodged easily.
Grading depends on :
- level of factor present
- If bleeding is only on trauma, on small injury or spontaneous
- frequency; rarely, once per month, once or more per week
- site; rarely in joints, sometimes in joints, often in joints
Mild, moderate and severe
What are the anatomical changes that occur in varicose veins?
Within the veins:
- Valves are ineffective (leaflets don’t touch oneanother)
- The vessels are twisted (straight flow isn’t possible)
- The vessel walls thin
Normally the veins are straight and the valve leaflets touch.
What is a thrombus?
A blood clot.
When blood is static, the platelets spend more time in contact with the endothelium, increasing their chance of clotting.
When blood is lamellar in flow, all the blood is moving.
When blood is turbulent only some blood is moving, therefore more stasis.
What is an embolus?
Any detached intravascular solid, liquid or gas that is carried to a site distant from its origin
Note: emboli can be any size, the larger the embolus, the larger the area of ischemia.
Where do thrombuses more commonly form?
- Chambers of the heart
- Valves of the heart
- Peripheral arteries and veins, especially the deep veins of the lower limbs
What is factor five Leiden mutation?
An innate hypercoagulability (primary hypercoagulability)
Can you give an example of an acquired (secondary) hypercoagulability?
Atrial fibrillation
What is happening when a clot is recannulised?
Smooth muscle and fibroblasts in the endothelium grow in to the thrombus.
May form channels in the thrombus large enough for blood flow to continue normally.
What is the most likely cause of a fat embolus?
Orthopaedic trauma
- releases fat from the bone marrow in to he vasculature.
Which parts of the body is an embolus from an arterial source most likely to be found in?
Brain
Abdominal organs
Extremities: legs and arms
This is all because of the systemic supply pushing the blood out to these places.
Which parts of the body is an embolus from an venous source most likely to be found in?
Pulmonary vasculature - greatest source of pulmonary embolism
This is why the biggest source of PE is DVT.
Think: it will return to the SVC and be passed through the pulmonary system, with lots of small arterioles to get caught in.
What are the signs of a deep vein thrombosis?
Unilateral lower limb affected
Warm calf
Calf swelling: >3cm circumference than unaffected leg (10cm below tibial tuberosity
Calf tenderness (worse on dorsiflexion = Homan’s sign)
