Case 6- Haematology

Question 1

Investigations for suspected DVT

Answer 1

Calf examination- measurement and palpation (hard)
Wells criteria for DVT
D dimmer if low wells- good to rule it out
Compression ultrasonography with Doppler of high wells score- gold standard
NICE recommend investigating unprovoked/ familial VTE (CT TAP or hereditary thrombophilia study)

Question 2

Management of a DVT

Answer 2

Avoid bed rest
Compression therapy
DOAC- apixaban, rivaroxaban when diagnosis suspected (LMWH if pregnant, unfractioned heparin if egfr below 15, DOAC’s okay between 15-50))- if D dimer or scan can’t be done within 4 hours, give anyway
Thrombolysis if PE and haemodynamically unstable/ slow response to AC
Thrombectomy if phlegmasia cerulea dolens
Long term anticoagulation- 3 month if provoked, 6 months if unprovoked or active cancer

Question 3

Investigations for a suspected PE

Answer 3

Respiratory examination
ECG- heart strain (may warrant echo)
FBC, UE, ABG, clotting screen
Wells score
CTPA if wells score likely (or VQ if contraindicated)
D diner if wells score unlikely (if positive, CTPA)
CXR- exclude other causes
Bilateral leg compression ultrasound with Doppler (DVT)
Check for malignancy and thrombophilia if no cause identified (remember this)

Question 4

Management of a PE

Answer 4

Supportive management eg. Fluids, O2
Initially DOAC (apixaban or rivaroxaban)
LMWH renal impairment or pregnancy
Long term anticoagulation- 3 months if provoked, 6 months if unprovoked or active cancer
Thrombolysis- large PE/ haemodynamic compromise. ICU step up here

NB- if clinical signs and wells point towards it, can treat with LMWH before CTPA results are back

Question 5

Investigations for haemophilia

Answer 5

FBC (anaemia) LFT (impairment- not producing enough clotting factors?)
Clotting screen with factor quantification (check for vin willebrand factor)
Blood film
Mixing study- doesn’t involve Von willebrand factor (I’d corrects- it’s a factor deficiency)

Question 6

Sx of PE

Answer 6

Dyspnoea, pleuritic chest pain, signs of a DVT, hypoxaemia, cough, haemoptysis, tachycardia, fever, raised JVP, pleural rub, syncope

Question 7

Wells score

Answer 7

Above 2= likely for a DVT
Above 5= likely for a PE

Question 8

Thrombophilia investigations

Answer 8

History- FH
Inquire about acquired causes and risk factors (e.g., medications, obstetric history, trauma)

Laboratory tests
Coagulation studies: active partial thromboplastin time (prolonged in antiphospholipid antibody syndrome)
ESR: elevated in malignancy or lupus
Antiphospholipid antibody panel (lupus anticoagulant, anticardiolipin, beta2-glycoprotein I antibody)
Heparin-induced thrombocytopenia tests: complete blood count (thrombocytopenia with heparin use), serotonin release assay (positive), antiplatelet factor 4 antibody (positive)
Hypercoagulability panel: APC resistance/factor V Leiden assay, prothrombin gene molecular analysis, protein C and S levels, antithrombin-heparin cofactor assay
Imaging: consider CT scan if a malignancy is suspected

NB- patient must be off anticoagulants for 3 weeks and non pregnant

Question 9

Differentials for haemophilia

Answer 9

Non accidental injury/ domestic abuse, VWB, deficiency of another clotting factor

Question 10

VWB Sx

Answer 10

Bleeding from minor wounds, post operative bleeding, easy and excessive bruising, menorrhagia, anaemia, GI bleeding, epistaxis, anaemia (mucosal bleeding)

Question 11

WVD Management

Answer 11

Only when Sx occur/ major bleeding/ surgery

1) recombinant VWF with factor 8
2) Desmopressin- stimulates factor 8 and VWF from cells
3) TXA - women with menorrhagia

Question 12

PE and ABG

Answer 12

Respiratory alkalosis- one of the few causes

High resp rate causes them to blow off CO2- also have a low O2

Question 13

Management of haemophilia

Answer 13

Fast track in AE
Avoid anticoagulants/ antiplatelets eg. Aspirin
RICE the affected limb (rest, immobilise, cool, elevate)
Prophylactic treatment- expensive, offered to kids to prevent joint destruction (recombinant factor concentrate, TXA or desmopressin in haemophilia A)

Question 14

DVT differentials

Answer 14

Bakers cyst, cellulitis, muscle haematoma

Question 15

Taking a coagulopathy history

Answer 15

Personal history of bleeding

Unexpected bruising, without trauma
Epistaxis, high frequency, greater than 30 minutes
GI tract bleeds- haematemesis, malaena, occult or fresh blood in stools
Menstruation- duration, flooding, clots, pads used each time
Urine- haematuria
Surgical and dental history

Family history

Any diagnosed bleeding disorders
Known bleeding after surgery or dentistry

Question 16

Risk factors for VTE

Answer 16

Is suspect VTE based on presenting history-ask about risk factors

Question 17

Heparin issues

Answer 17

Heparin induced thrombocytopenia or hyperkalaemia

Question 18

Flow diagram for investigating DVT

Answer 18

See gallery

Question 19

Alternative name of factor V Leiden

Answer 19

Activated protein C resistance

Question 20

Causes of hereditary haemolytic anaemia

Answer 20

Hereditary spherocytosis
GP6D deficiency
Sickle cell disease
Thalassaemia

Question 21

Immune causes of acquired haemolytic anaemia

Answer 21

Autoimmune haemolytic anaemia (cold/warm)
Haemolytic disease IPF the newborn
Transfusion reaction
Penicillin, methyldopa

Question 22

Non immune causes of haemolytic anaemia

Answer 22

TTP, HUS, DIC, malignancy
Prosthetic heart valves
Paroxysmal nocturnal haemoglobinuria
Infection eg. Malaria

Question 23

Hereditary spherocytosis features

Answer 23

Failure to thrive
Jaundice, gall stones
Splenomegaly
Aplastic crisis (parvovirus infection)
Haemolytic anaemia
Raised MCHC
Clinical diagnosis, but can perform a EMA binding test

Question 24

Management of HS

Answer 24

Acute- supportive, management
Longer term- folate, splenectomy

Question 25

Causes of thrombophilia

Answer 25

Inherited
-factor V Leiden (most common cause)
-prothrombin gene mutation
-antithrombin III, protein C, protein S deficiency

Acquired
-antiphospholipid syndrome
-combined OCP

Question 26

Medications that increase VTE

Answer 26

Combined OCP, HRT, raloxifene, tamoxifen, antipsychotics (olanzapine)

Question 27

Vitamin B12

Answer 27

Parietal cells in stomach produce IF
B12 is actively absorbed in the terminal ileum

Question 28

Causes of B12 deficiency/ anaemia

Answer 28

Pernicious anaemia
Post gastrectomy or ileocaecal resection
Vegan or poor diet
Absorption disorders eg, Crohns
Metformin

Question 29

Features of B12 deficiency

Answer 29

Macrocytic anaemia
Sore tongue and mouth
Neurological symptoms- Parasthesia and peripheral neuropathy
Neuropsychiatric symptoms- mood disturbances

Question 30

Management of vitamin B2 deficiency

Answer 30

Treat B12 before folate (think alphabet)- prevent subacute combined degeneration if the cord

IM hydroxocobalamin (3x week for 2 weeks, then once every 3 months)

Question 31

Symptoms of haemophilia

Answer 31

Spontaneous bleeds- joints (subsequent destruction), muscle and soft tissues
Recurrent bruising and haematoma formation, mucosal bleeding
Sx of haemorrhage eg. headache, neck stiffness, melaena, haematemesis, haematuria

Question 32

Flow diagram for investigating PE

Answer 32

See gallery

Question 33

Renal impairment and PE

Answer 33

Do a VQ scan as it doesn’t need contrast

Question 34

ECG changes with a PE

Answer 34

S1Q3T3- large S wave in lead I, large Q wave in lead III, inverted T wave in lead III (1/5)
Sinus tachycardia (most common)
RBBB and right axis deviation

Question 35

What guidelines can be used to manage PE patients at home

Answer 35

PESI score and guidelines