Case 6- Haematology Flashcards
Investigations for suspected DVT
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)
Management of a DVT
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
Investigations for a suspected PE
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)
Management of a PE
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
Investigations for haemophilia
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)
Sx of PE
Dyspnoea, pleuritic chest pain, signs of a DVT, hypoxaemia, cough, haemoptysis, tachycardia, fever, raised JVP, pleural rub, syncope
Wells score
Above 2= likely for a DVT
Above 5= likely for a PE
Thrombophilia investigations
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
Differentials for haemophilia
Non accidental injury/ domestic abuse, VWB, deficiency of another clotting factor
VWB Sx
Bleeding from minor wounds, post operative bleeding, easy and excessive bruising, menorrhagia, anaemia, GI bleeding, epistaxis, anaemia (mucosal bleeding)
WVD Management
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
PE and ABG
Respiratory alkalosis- one of the few causes
High resp rate causes them to blow off CO2- also have a low O2
Management of haemophilia
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)
DVT differentials
Bakers cyst, cellulitis, muscle haematoma
Taking a coagulopathy history
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
Risk factors for VTE
Is suspect VTE based on presenting history-ask about risk factors
Heparin issues
Heparin induced thrombocytopenia or hyperkalaemia
Flow diagram for investigating DVT
See gallery
Alternative name of factor V Leiden
Activated protein C resistance
Causes of hereditary haemolytic anaemia
Hereditary spherocytosis
GP6D deficiency
Sickle cell disease
Thalassaemia
Immune causes of acquired haemolytic anaemia
Autoimmune haemolytic anaemia (cold/warm)
Haemolytic disease IPF the newborn
Transfusion reaction
Penicillin, methyldopa
Non immune causes of haemolytic anaemia
TTP, HUS, DIC, malignancy
Prosthetic heart valves
Paroxysmal nocturnal haemoglobinuria
Infection eg. Malaria
Hereditary spherocytosis features
Failure to thrive
Jaundice, gall stones
Splenomegaly
Aplastic crisis (parvovirus infection)
Haemolytic anaemia
Raised MCHC
Clinical diagnosis, but can perform a EMA binding test
Management of HS
Acute- supportive, management
Longer term- folate, splenectomy
Causes of thrombophilia
Inherited
-factor V Leiden (most common cause)
-prothrombin gene mutation
-antithrombin III, protein C, protein S deficiency
Acquired
-antiphospholipid syndrome
-combined OCP
Medications that increase VTE
Combined OCP, HRT, raloxifene, tamoxifen, antipsychotics (olanzapine)
Vitamin B12
Parietal cells in stomach produce IF
B12 is actively absorbed in the terminal ileum
Causes of B12 deficiency/ anaemia
Pernicious anaemia
Post gastrectomy or ileocaecal resection
Vegan or poor diet
Absorption disorders eg, Crohns
Metformin
Features of B12 deficiency
Macrocytic anaemia
Sore tongue and mouth
Neurological symptoms- Parasthesia and peripheral neuropathy
Neuropsychiatric symptoms- mood disturbances
Management of vitamin B2 deficiency
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)
Symptoms of haemophilia
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
Flow diagram for investigating PE
See gallery
Renal impairment and PE
Do a VQ scan as it doesn’t need contrast
ECG changes with a PE
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
What guidelines can be used to manage PE patients at home
PESI score and guidelines
