[vc_row row_type=”row” use_row_as_full_screen_section=”no” type=”full_width” oblique_section=”no” text_align=”left” css_animation=””][vc_column][ultimate_heading main_heading=”Candidate brief” main_heading_color=”#000000″ sub_heading_color=”#000000″ main_heading_style=”font-weight:bold;” main_heading_font_size=”desktop:36px;”]

Patient Details: Ms Laura Dixon, 43 years old

Your Role: Doctor in general medical out-patient clinic

Complaint: Leg swelling and pain

Referral Text

Dear Doctor,

I would be grateful if you could assess Ms Dixon for a swollen leg.

Your role is to take a thorough history from the patient and, based on the information you obtain, construct a differential diagnosis and investigative plan for investigation.

You should also then explain these to the patient and answer any questions or concerns they may have.
          Do not examine the patient and ensure you return all
          papers to the examiner at the end of the exam.

[/ultimate_heading][vc_empty_space image_repeat=”no-repeat”][vc_video link=”https://vimeo.com/208125989″][vc_empty_space image_repeat=”no-repeat”][vc_row_inner row_type=”row” type=”full_width” use_row_as_full_screen_section_slide=”no” text_align=”left” css_animation=””][vc_column_inner width=”1/6″][no_counter type=”zero” box=”no” position=”center” underline_digit=”no” separator=”yes” digit=”5″ title=”Minutes” text=”Time to prepare before station begins”][/vc_column_inner][vc_column_inner width=”1/6″][no_counter type=”zero” box=”no” position=”center” separator=”yes” digit=”20″ title=”Minutes” text=”Time for this station”][/vc_column_inner][vc_column_inner width=”1/6″][no_counter type=”zero” position=”center” separator=”yes” digit=”14″ title=”Minutes” text=”Time to talk to your patient”][/vc_column_inner][vc_column_inner width=”1/6″][no_counter type=”zero” position=”center” separator=”yes” digit=”1″ title=”Minutes” text=”Pause for reflection”][/vc_column_inner][vc_column_inner width=”1/6″][no_counter type=”zero” position=”center” separator=”yes” digit=”5″ title=”Minutes” text=”Time for discussion and questions with examiners”][/vc_column_inner][vc_column_inner width=”1/6″][/vc_column_inner][/vc_row_inner][vc_empty_space image_repeat=”no-repeat”][/vc_column][/vc_row][vc_row row_type=”row” use_row_as_full_screen_section=”no” type=”full_width” oblique_section=”no” text_align=”left” css_animation=””][vc_column][vc_accordion style=”accordion”][vc_accordion_tab title=”Common examiner questions”][vc_column_text]Common examiner questions include the following:

[/vc_column_text][/vc_accordion_tab][vc_accordion_tab title=”Diagnosis and clinical signs”][vc_column_text]This patient has symptoms in keeping with a deep vein thrombosis due to possible recurrence of pancreatic cancer, with no other obvious risk factors.[/vc_column_text][/vc_accordion_tab][vc_accordion_tab title=”Discussion”][vc_column_text]Thrombosis refers to the formation, from blood components, of an abnormal mass within the vascular system. When this process occurs within the deep veins, commonly in the legs, it is referred to as a deep vein thrombosis (DVT). Colloquially it is known as long haul flight syndrome.

The main reason to diagnose a DVT is to treat prior to the development of a pulmonary embolus (PE), as well as preventing development of post-phlebitis syndrome and pulmonary hypertension (secondary to chronic pulmonary embolic disease).

Annually, DVT affects approximately 0.1% of the general population. Pregnant women have a much higher risk of all types of venous thrombotic emboli (VTE) than the non-pregnant of similar age and there is an even higher risk after caesarean section compared to vaginal delivery. Post general surgical procedures risk is 15-40%. This increases to 40-60% after hip or knee replacement surgery.

Pathophysiology

The formation of the thrombus most commonly begins in the valve pockets of the veins of the calf and extends proximally. It is composed primarily of fibrin and red blood cells.

Virchow’s triad describes the combination of endothelial injury, venous stasis and hypercoagulability of blood.

Classification of lower limb DVT:

  • proximal (popliteal vein or thigh veins)
    • active cancer / cancer treatment
    • congestive cardiac failure
    • chronic respiratory disease
    • 75-years of age or older
    • most associated with fatal PE
  • distal (calf veins)
    • recent surgery
    • prolonged immobilisation

Some people also develop a post-thrombotic syndrome, which, if it occurs, is established by 1-year in up to half of cases of DVT:

  • recurrent leg swelling
  • pain
  • skin induration

Presenting Features

As with all of medicine, history and clinical examination are key.

Symptoms and signs:

  • pain
  • swelling
  • warmth/heat
  • erythema

Risk factors

  • prolonged immobility (for any reason)
  • previous venous thrombotic events
  • congestive heart failure
  • acute systemic infection
  • pregnancy
  • dehydration
  • hormonal treatment
  • rheumatological disease
  • medications (such as the oral contraceptive pill)

D-dimer

There is a nearly 100% negative predictive value for patients with a negative D-dimer blood test. There is a high sensitivity and poor specificity.

Causes of false positive d-dimer results:

  • malignancy of any kind
  • elderly (and the use of age adjusted d-dimers is still being researched)
  • pregnancy
  • inflammatory

Investigations

For DVT, venous ultrasonography is the imaging modality of choice. If thrombus is present then there is a lack of compression of the lumen under pressure. The colour Doppler demonstrates a loss of colour. This imaging can also diagnose other conditions that can mimic a DVT, such as a ruptured Baker’s cyst, haematomas, certain aneurysms and thrombophlebitis.

If DVT is confirmed then in this patient a contrast enhanced computer tomography of the chest, abdomen and pelvis is required to detect recurrence of the pancreatic cancer, or detect other possible solid organ malignancies.

Baseline blood tests needed include a platelet count and clotting levels to guide treatment of DVT.

Management

The mainstay of direct DVT treatment is anti-coagulation to reduce the thrombotic predilection of the blood:

  • low molecular weight heparin – LMWH (dalteparin, clexane and tinzaparin)
    • does not require monitoring
  • unfractionated heparin
    • requires regular monitoring
  • fondaparinux (also used for acute coronary syndrome)
  • vitamin K antagonist (warfarin)
    • requires regular monitoring, dietary restriction and regulation of alcohol
  • novel oral anti-coagulant – NOAC (rivaroxaban, apixaban, dabigatran)
    • does not require monitoring

Duration of treatment depends upon the location of the VTE and cause (underlying pathology and whether the VTE is provoked versus unprovoked). For example, in malignancies, LMWH is the treatment of choice due to the risks of bleeding into a solid tumour from oral anti-coagulants.

Depending upon where you practice, not only internationally but within the United Kingdom, treatment policies will differ, and this is primarily related to cost. Warfarin is still the cheapest option as it is off-patent. NOAC are the most expensive and as they are still relatively new, their long term usage is yet to be determined. However, all options have their advantages and disadvantages.

There are benefits and risks which are common to all anti-coagulation therapy:

  • Benefits:
    • reduced risks of clots
    • reduces morbidity mortality significantly
  • Risks:
    • increased risk of bleeding both minor and major
    • increased haemorrhagic events if taking others such as NSAIDs
    • can affect lifestyle (such as sports)

However, there are also drug specific advantages and disadvantages.

Warfarin:

  • Advantages:
    • cheapest
    • well recognised understanding among health care professionals of monitoring and managing complications
    • long term (over decades) use and effects well understood
    • available everywhere
    • reversal agent available
  • Disadvantages
    • higher risk of large haemorrhagic events versus smaller bleeding events
    • requires diet modification (vitamin K containing foods)
    • requires regulation of alcohol intake
    • regular blood tests

Heparin:

  • Advantages:
    • safest in malignancy
    • readily reversible
    • prophylaxis dose available
  • Disadvantages:
    • daily needles (administration of the drug and disposal)
    • complications such as lipodystrophy or heparin induced thrombocytopaenia

Novel Oral Anti-Coagulants (NOAC)

  • Advantages
    • no blood monitoring
    • no dietary or alcohol restrictions
  • Disadvantages
    • long term effects still unknown
    • expense
    • only Dabigatran has a recently released reversal agent
    • increased minor haemorrhagic events versus major
    • controversy over peak and trough levels between doses

[/vc_column_text][/vc_accordion_tab][vc_accordion_tab title=”Specimen case presentation”][vc_column_text]”This patient has symptoms in keeping with a deep vein thrombosis due to possible recurrence of pancreatic cancer, with no other obvious risk factors. I would like to arrange baseline blood tests including a full blood count and clotting screen, and an ultrasound doppler of the lower limb to confirm the diagnosis”[/vc_column_text][/vc_accordion_tab][/vc_accordion][/vc_column][/vc_row]