Miscellaneous Haematology Flashcards
Antiphospholipid syndrome
Acquired disorder characterised by a hypercoaguable state
May be a primary disorder or secondary to SLE
Causes a paradoxical rise in APTT
Features of antiphospholipid syndrome
Venous or atrial thrombosis
Recurrent foetal loss
Livedo reticularis
Thrombocytopenia
Prolonged APTT
Pre eclampsia, pulmonary HTN
Antibodies associated with AP syndrome
Lupus anticoagulant
Anticardiolipin antibodies
Anti beta 2 glycoprotein I antibodies
Management of AP syndrome
Primary (no previous thrombi)- low dose aspirin
Secondary- lifelong warfarin with INR 2-3 (if continued add low dose aspirin and raise to 3-4)
Management of AP syndrome in pregnancy
Low dose aspirin when pregnancy confirmed
LMWH when foetal heart detected (stop at 34 weeks)
Non haemolytic febrile reaction
Fever, chills
Slow/stop the transfusion, paracetamol, monitor
Minor allergic reaction
Pruritus, urticaria
Temporarily stop the infusion, antihistamine, monitor
Anaphylaxis
Patients with IgA deficiency who have anti IgA antibodies
Hypotension, dyspnoea, wheezing, angioedema
Stop transfusion, IM adrenaline, ABC support
Acute haemolytic reaction
Fever, abdominal pain, hypotension, dark urine (3 hours post-transfusion)
ABO incompatible blood (human error). IgM destruction of RBC’s
Stop, send blood for Coombs test, repeat cross matching, supportive care
Transfusion associated circulatory overload
Pulmonary oedema, HTN
Slow transfusion, IV loop diuretics and oxygen
NB- The normal central venous pressure (normal = 0- 6 mmHg) is less consistent with fluid overload.
Transfusion related acute lung injury
Hypoxia, pulmonary infiltrates on CXR, fever, hypotension
Stop, oxygen and supportive care
Irradiated blood products
Depleted of T lymphocytes
Avoid transfusion associated graft versus host disease
Immune thrombocytopenia purpura
Immune mediated reduction in platelet count
Kids- often following an infection or vaccination
Adults- more chronic condition
Megakaryocytes in the bone marrow
ITP Features
Petechiae
Purpura
Bleeding
Catastrophic bleeding is rare
Type II hypersensitivity reaction
NB- can have anaemia alongside it (esp. if someone is bleeding)
Management of ITP
Emergency treatment: life-threatening or organ threatening bleeding: Platelet transfusion, IV methylprednisolone and intravenous immunoglobulin
Otherwise, PO steroids
Thrombotic thrombocytopenia purpura
ADAMST13
Platelet clots form in vessels leaving blood unable to clot so liable to bleed
Features
-fever
-fluctuating neuro signs (microemboli)
-microangiopathic haemolytic anaemia
-thrombocytopenia
-renal failure
Causes of TTP
Post infection (urinary, GI)
Pregnancy
Drugs- ciclosporin, OCP, penicillin
Tumours
SLE
HIV
Disseminated intravascular coagulation
Dysregulation of coagulation and fibrinolysis, leading to widespread clotting and resultant bleeding
TF released
Causes of DIC
Sepsis
Trauma
Obstetric complications eg. Amniotic fluid embolism or HELLP syndrome
Malignancy
NB- manage with FFP and cryoprecipitate
Typical blood picture of DIC
Decreased platelets
Decreased fibrinogen
Increased PT and APTT
Increased fibrinogen degradation products
Schistocytes due to microangiopathic haemolytic anaemia
Management of TTP
Plasma exchange
Steroids
Rituximab
Heparin induced thrombocytopenia
Antibodies developed against platelets in response to heparin
Features diagnosis and management of HIT
Antibodies activate a hypercoaguable state causing thrombosis and break down platelets causing thrombocytopenia (also hyperkalaemia)- A PROTHROMBITIC STATE
Diagnosis- HIT antibodies in blood
Management- switch to a different AC (eg. a direct thrombin inhibitor such as argatroban)
Acute graft versus host disease (GVHD)
Within 100 days of transplantation
Painful maculopapular rash (progress to toxic epidermal necrosis)
Jaundice
Watery or bloody diarrhoea
N and v
Culture negative fever
Steroids
Chronic GVHD
100 days after transplantation
Can arise after cute disease or de novo
Scleroderma, vitiligo
Conjunctivitis, corneal ulcers, scleritis
Dysphagia, oral ulcers and lichenous changes
Obstructive or restrictive lung disease
IV steroids
Features of hereditary angioedema
Attacks preceded by painful macular rash
Painless, non pruritic swelling of subcutaneous tissues
May effect upper airway, skin, or abdominal organs
Management of hereditary angioedema
Acute- IV C1 inhibitor concentrate, FFP
Prophylaxis- anabolic steroid (danazol)
Causes of hyposplenism
Splenctomy
Sickle cell
Coeliac disease
Graves’ disease
SLE
amyloid
Lead poisoning features
Abdominal pain
Peripheral neuropathy (mainly motor)
Fatigue
Constipation
Blue limes on gum margin
Management of lead poisoning
Chelating agents
DMSA
EDTA
Dimercapol
D pencillamine
Management of neutropenic sepsis
Don’t wait for bloods, start antibiotics
Piperacillin and taxaobactam
But in meningitis, if LP can be done in an hour, do that, then ABX
Polycythaemia rubra Vera
Myeloproliferative disorder, often overproduction of RBC’s, neutrophils, platelets
JAK2 mutation
Older people
Features of PRV
Hyperviscosity, pruritus (after hot bath), Splenomegaly, haemorrhage, plethoric appearance, HTN, low ESR
Tests for PRV
FBC (raised cell numbers)
JAK2 mutation
Serum ferritin
UE LFT
Differentiate true (primary or secondary) and relative polycythaemia
Red cell mass studies
PRV Management
Aspirin
Regular venesection/ phlebotomy
Chemotherapy
NB- thrombotic events can be a cause of mortality and a proportion will progress to Myelofibrosis and acute leukaemia
Causes of Splenomegaly
Myelofibrosis
Haematological malignancy
Malaria
Portal hypertension secondary to cirrhosis
Haemolytic anaemia eg. hereditary spherocytosis
Thalassaemia
Rheumatoid arthritis (RA)
EBV
Essential thrombocytosis
Myeloproliferative disorder which overlaps with CML, PRV, and Myelofibrosis
Features of thrombocytosis
Increased platelet count
Thrombosis and haemorrhage seen
Burning sensation in the hands
JAK2 mutation
Management of thrombocytosis
Hydroxyurea
Aspirin
Interferon alpha
Administration of TXA
IV bolus followed by an infusion in cases of major haemorrhage
What is the most common inherited bleeding disorder?
VWD- autosomal dominant inheritance
Rouloux formation
Myeloma
Post thrombotic syndrome
Painful heavy calves
Itching
Swelling
Varicose veins
Venous ulceration
Treat with compression stockings and elevated legs
Direct vs indirect Coomb’s test
Direct- autoimmune haemolysis (spherocytes in haemolytic anaemia)
Indirect- haemolytic disease of the newborn
Antiplatelet therapy and dental surgery
Antiplatelet therapy shouldn’t not be changed
Indications for platelet transfusion in active bleeding
Platelet count of <30 x 10 9 and clinically significant bleeding eg. haematemesis, melaena, prolonged epistaxis
Or platelet count of < 100 x 10 9 for patients with severe bleeding, or bleeding at critical sites, such as the CNS
NB- higher risk of bacterial contamination than other blood products
Indications for platelet transfusion if no active bleeding
Platelet count of 10 x 10 9 except where platelet transfusion is contraindicated or there are alternative treatments for their condition
For example, do not perform platelet transfusion for any of the following conditions:
Chronic bone marrow failure
Autoimmune thrombocytopenia
Heparin-induced thrombocytopenia, or
Thrombotic thrombocytopenic purpura.
Platelet levels to aim for prior to surgery/ invasive procedure
> 50×109/L for most patients
50-75×109/L if high risk of bleeding
100×109/L if surgery at critical site
NB- don’t get platelet level and Hb level confused
Cryoprecipitate
Factor VIII
Fibrinogen
von Willebrand factor
Factor XIII
Blood product made from plasma
Usually transfused as 6 unit pool
Indications include massive haemorrhage and uncontrolled bleeding due to haemophilia
Acquired haemophilia
Factor 8 acquired disorder. The elderly, pregnancy, malignancy and autoimmune conditions are associated with acquired haemophilia. Prolonged APTT is key to the diagnosis. Management involves steroids.
Drug induced thrombocytopenia
quinine
abciximab
NSAIDs
diuretics: furosemide
antibiotics: penicillins, sulphonamides, rifampicin
anticonvulsants: carbamazepine, valproate
heparin
NB- if not one of these drugs and an isolated thrombocytopenia in a well person, think ITP
Blood loss in surgery
Unlikely- Group and save
Hysterectomy (simple), appendicectomy, thyroidectomy, elective lower segment caesarean section, laparoscopic cholecystectomy
Likely- Cross-match 2 units
Salpingectomy for ruptured ectopic pregnancy, total hip replacement
Definite- Cross-match 4-6 units
Total gastrectomy, oophorectomy, oesophagectomy, Elective AAA repair, cystectomy, hepatectomy
Amyloidosis
amyloidosis is a term which describes the extracellular deposition of an insoluble fibrillar protein termed amyloid
amyloid is derived from many different precursor proteins
in addition to the fibrillar component, amyloid also contains a non-fibrillary protein called amyloid-P component, derived from the acute phase protein serum amyloid P
other non-fibrillary components include apolipoprotein E and heparan sulphate proteoglycans
the accumulation of amyloid fibrils leads to tissue/organ dysfunction
Classification
systemic or localized
Diagnosis
Congo red staining: apple-green birefringence
serum amyloid precursor (SAP) scan
biopsy of skin, rectal mucosa, or abdominal fat
Porphyria cutanea tarda
Porphyria cutanea tarda is the most common hepatic porphyria. It is due to an inherited defect in uroporphyrinogen decarboxylase or caused by hepatocyte damage e.g. alcohol, hepatitis C, oestrogen.
Features
classically presents with photosensitive rash with blistering and skin fragility on the face and dorsal aspect of hands (most common feature)
hypertrichosis
hyperpigmentation
Investigations
urine: elevated uroporphyrinogen and pink fluorescence of urine under Wood’s lamp
serum iron ferritin level is used to guide therapy
Management
chloroquine
venesection (preferred if iron ferritin is above 600 ng/ml)
Acute intermittent porphyria
Acute intermittent porphyria (AIP) is a rare autosomal dominant condition caused by a defect in porphobilinogen deaminase, an enzyme involved in the biosynthesis of haem. The results in the toxic accumulation of delta aminolaevulinic acid and porphobilinogen. It characteristically presents with abdominal and neuropsychiatric symptoms in 20-40-year-olds. AIP is more common in females (5:1)
The classical presentation is a combination of abdominal, neurological and psychiatric symptoms:
abdominal: abdominal pain, vomiting
neurological: motor neuropathy
psychiatric: e.g. depression
hypertension and tachycardia common
Diagnosis
classically urine turns deep red on standing
raised urinary porphobilinogen (elevated between attacks and to a greater extent during acute attacks)
assay of red cells for porphobilinogen deaminase
raised serum levels of delta aminolaevulinic acid and porphobilinogen
Management
avoiding triggers
acute attacks
IV haematin/haem arginate
IV glucose should be used if haematin/haem arginate is not immediately available
Matching antigens in blood transfusions
HLA-DR, specifically HLA-DRB3/4/5, is the most important set of antigens to match.
B and A antigens are the next most important.
C and DQ are less important.
Reticulocytes and chronic blood loss
In chronic blood loss, reticulocyte count would typically increase as the bone marrow produces more red blood cells.
Folate vs B12 anaemia
Folate deficiency is a cause of macrocytic anaemia however it does not cause neurological symptoms such as peripheral neuropathy or confusion- B12/pernicious anaemia.
Warfarin and emergency surgery
If surgery can wait for 6-8 hours - give 5 mg vitamin K IV
If surgery can’t wait - 25-50 units/kg four-factor prothrombin complex
Warfarin and emergency surgery
If surgery can wait for 6-8 hours - give 5 mg vitamin K IV
If surgery can’t wait - 25-50 units/kg four-factor prothrombin complex
Differentiate true polycythaemia (ie. PRV) from secondary
The patient in this example has a normal SpO2 and EPO which suggest that the polycythaemia is not secondary in nature. T
Haemolysis and haptoglobins
low haptoglobins
One way to differentiate Myeloid and Lymphocytic leukaemia’s
LL- usually raised lymphocytes
ML- raised myeloid lineage cells eg. neutrophils and thrombocytes (platelets)
