3. Factors predisposing to venous
thrombosis
Patient factors
• Increasing age
• Obesity
• Varicose veins
• Previous DVT
• Family history
• Pregnancy/puerperium
• Oestrogen
• Immobility (> 4 hrs)
Surgical conditions
• Major surgery, especially
if > 30 mins’ duration
• Abdominal or pelvic
surgery, especially for
cancer
• Major lower limb
orthopaedic surgery,
e.g. joint replacement
and hip fracture surgery
4. Medical conditions
• Myocardial
infarction/heart failure
• Inflammatory bowel
disease
• Malignancy
• Nephrotic syndrome
• Pneumonia
• Neurological conditions
e.g. stroke, paraplegia,
GBS
Haematological disorders
• Deficiency of
anticoagulants:
antithrombin, protein C,
protein S
• Paroxysmal nocturnal
haemoglobinuria
• Myeloproliferative
disorders
Antiphospholipid syndrome
5. Clinical assessment
• Lower limb DVT characteristically starts in the
distal veins, causing pain, swelling, an increase
in temperature and dilatation of the
superficial veins in one leg.
• The differential diagnosis includes ruptured
Baker’s cyst and cellulitis.
• Symptoms and signs of PE should be sought,
particularly in those with proximal
thrombosis.
6. Investigations
• Compression ultrasound (Doppler study) is the
imaging modality of choice
• D-dimer levels
• Investigation for predisposing factors may be
considered
• CT pulmonary angiogram for suspected
pulmonary embolism
7. Management
• The management of leg DVT includes elevation and
analgesia.
• Thrombolysis may be considered for limb threatening DVT,
but the mainstay of treatment is anticoagulation with low
molecular weight heparin (LMWH), followed by a coumarin
anticoagulant, such as warfarin.
• An alternative is the oral Xa inhibitor, rivaroxaban, which
has a rapid onset of action and can be used immediately
from diagnosis without the need for LMWH.
• Treatment of acute VTE with LMWH should continue for at
least 5 days. If a coumarin is being introduced, the heparin
should continue until the INR has been in the target range
(2–3) for 2 days.
8. Management
• The optimal initial duration of anticoagulation is
between 6 weeks and 6 months. Patients who
have thrombosis in the presence of a temporary
risk factor, which is then removed, can usually be
treated for shorter periods (e.g. 3 months) than
those who sustain unprovoked thrombosis.
• In patients with active cancer and VTE, there is
evidence that LMWH should be continued for 6
months rather than being replaced by a
coumarin.
9. • Inspect the legs for obvious oedema and examine for
pitting oedema. Press firmly but gently for around 5
seconds behind the medial malleolus, over the dorsum of
the foot and on the shin.
• Ankle, foot and sacrum for 15 min.
• The affected limb will be swollen. The circumference of the
calf should be measured and compared with the unaffected
leg, at the same distance below the tibial tuberosity. A
discrepancy of more than 1 cm is significant.
• The affected leg is also tender and warmer than normal,
with dilated superficial veins which do not collapse when
the leg is elevated.
10. Atherosclerosis
• Atherosclerosis is a progressive inflammatory
disorder of the arterial wall that is
characterised by focal lipid rich deposits of
atheroma.
• Mode of presentation – in the heart, it may
cause angina, MI and sudden death; in the
brain, stroke and transient ischaemic attack
(TIA); and in the limbs, claudication and
critical limb ischaemia.
11. Risk factors
• Age and sex
• Family history
• Smoking
• Hypertension
• Hypercholesterolaemia
• Diabetes mellitus
• Haemostatic factors
• Physical activity
• Obesity
• Alcohol - Alcohol
consumption is
associated with reduced
rates of coronary artery
disease. Excess alcohol
consumption is
associated with
hypertension and
cerebrovascular
disease.
12. Risk factors
• Other dietary factors - Diets deficient in fresh
fruit, vegetables and polyunsaturated fatty
acids are associated with an increased risk of
cardiovascular disease.
• Personality
• Social deprivation
13. Primary prevention
• Two complementary strategies can be used to
prevent atherosclerosis in apparently healthy
but at-risk individuals: population and
targeted strategies.
14. Targeted strategy
• The targeted strategy aims to identify and
treat high-risk individuals, who usually have a
combination of risk factors and can be
identified by using composite scoring systems
15. Secondary prevention
• The energetic correction of modifiable risk factors,
particularly smoking, hypertension and
hypercholesterolaemia, is particularly important
because the absolute risk of further vascular events is
high.
• All patients with coronary artery disease should be
given statin therapy, irrespective of their serum
cholesterol concentration.
• BP should be treated to a target of 140/85 mmHg or
lower. Aspirin and ACE inhibitors are of benefit in
patients with evidence of vascular disease.
• Betablockers benefit patients with a history of MI or
heart failure.
16. Peripheral arterial disease
• Lower limb ischaemia presents as two distinct
clinical entities: intermittent claudication (IC) and
critical limb ischaemia (CLI).
• The presence and severity of ischaemia can be
determined by clinical examination and
measurement of the ankle–brachial pressure
index (ABPI), which is the ratio between the
(highest systolic) ankle and brachial blood
pressures.
• In health, the ABPI is over 1.0, in IC typically 0.5–
0.9 and in CLI usually below 0.5.
19. Intermittent claudication
• This term describes ischaemic pain affecting
the muscles of the leg upon walking.
• The mainstay of treatment is BMT, including
exercise therapy.
• The peripheral vasodilator, cilostazol, has
been shown to improve walking distance.
• Intervention with angioplasty, stenting,
endarterectomy or bypass may be considered.
21. Critical limb ischaemia
• This is defined as rest (night) pain, requiring
opiate analgesia, and/or tissue loss (ulceration or
gangrene), present for more than 2 weeks, in the
presence of an ankle BP of less than 50 mmHg.
• In contrast to patients with IC, those with SLI are
at high risk of losing their limb, and sometimes
their life, in a matter of weeks or months without
surgical bypass or endovascular revascularisation
by angioplasty or stenting.