Haematology Flashcards
When should you suspect neutropenic sepsis?
- neutrophils < x?
- or new onset: ?
- in a neutropenic pt (<1x10^9) who is pyrexial
- or has new-onset confusion, tachycardia, HT, dyspnoea, or hypothermia
what sites should you examine when assessing a pt with suspected neutropenic sepsis:
-mucous membranes
-oropharynx (?thrush, erythema)
-surgical sites
-IV lines and other lines
NB: should swab and send for microscopy from all suspicious areas
Acute neutropenic sepsis management is start empirical IV abx e.g. _____ and aminoglycoside to cover gram __ and _______.
- if clinical deterioration/fever persists/suspected MRSA what abx should you add?
- when to swap to oral and continue for how long?
- empirical IV abx e.g. piperacillin
- cover gram negative and pseudomonas
- add Vancomycin
- swap to oral when apyrexial for 48hrs and continue for 10-14days
Suggest 5 causes of a neutropenia?
- african race
- viral infection
- severe bacterial infection
- megaloblastic anaemia
- pancytopenia
- drugs causing marrow aplasia or immune destruction
- inherited abnormalities
What happens in DIC?
- widespread fibrin generation in blood vessels caused by initiation of the coagulation pathway
- platelets and coagulation factors are consumed and fibrinolysis is activated secondarily
- leads to FDPs production that contribute to bleeding by inhibiting fibrin polymerisation
Suggest 2 triggers for DIC?
- release or expression of tissue factor
- extensive damage to vascular endothelium exposing TF or enhanced expression of TF by monocytes in response to cytokines
- sepsis
- major trauma
- tissue destruction (surgery, severe burns)
- advanced cancer
- obstetric complications (amniotic fluid embolism, abruptio placentae)
Why does DIC occur often in acute promyelocytic leukaemia?
-due to generation of procoagulant substances in the blood
Presentation of DIC is variable on a spectrum, suggest how it may present?
- no bleeding —> complete haemostatic failure (bleeding from venepuncture sites, nose, mouth….)
- thrombotic events occur due to vessel occlusion by platelets and fibrin
What investigations would you arrange in DIC and suggest their findings?
- prolonged PT, APPT and TT
- decreased fibrinogen
- elevated fibrin degradation products (FDPs)
- blood film: fragmented red cells
In chronic/mild cases of DIC, blood results (PT, APPT, TT) can be largely unremarkable or only show an in increase in the ___ reflecting accelerated ____
- FDPs (like D Dimers)
- accelerated fibrinolysis
DIC can be caused by: -vascular endothelium damage, exposed/increased TF by monocytes, sepsis, trauma, cancer, obstetric complications.. how is it treated?-
treat underlying condition, then for pts that are bleeding give:
- platelet concentrates to maintain count (>50x10^9)
- FFP
- cryoprecipitate
- red cell concentrated
Neutrophil leukocytosis (>10x10^9) suggest 4 causes:
- bacterial infection
- tissue necrosis
- inflammation
- corticosteroid therapy
- myeloproliferative disease
- acute haemorrhage, haemolysis
- leukemoid reaction (characterised by immature white cells in peripheral blood)
- leucoerythroblastic anaemia
Multiple myeloma is a malignant disease of which cells?
-clonal proliferation of these cells results in what in the blood/urine?
- The plasma cells of bone marrow
- Clonal proliferation of bone marrow plasma cells usually capable of producing monoclonal immunoglobulins (paraproteins) mostly IgG or IgA.
- Result is paraproteinaemia may be associated with excretion of light chains in urine
Multiple myeloma presents at average age of 60yrs
- the clinical features arise from it’s result on bone, kidneys and blood
- explain the issues with the bones:
More osteoclast activity -> -bone pain esp. back pain, -osteolytic lesions, -pathological fractures, -spinal cord compression -hypercalcaemia BM infiltration with plasma cells --> anaemia, infections, bleeding
Multiple myeloma presents at average age of 60yrs
- the clinical features arise from it’s result on bone, kidneys and blood
- explain the issues it causes with the kidney:
AKI due to:
- deposition of light chains in tubules
- hypercalcemia
- hyperuricemia
- amyloid deposition
Multiple myeloma presents at average age of 60yrs
- the clinical features arise from it’s result on bone, kidneys and blood
- explain the issues it can cause with the blood? leading to what sorts of symptoms?
- paraproteins can form aggregates in the blood which greatly increase the viscosity leading to: blurred vision, gangrene and bleeding
- infections occur due to a reduction of normal polyclonal immunoglobulin levels (immune paresis)
Investigating multiple myeloma
-requires 2 out of 3 diagnostic features to be present, what are these?
- paraproteinaemia on serum protein immunofixation / Bence Jones protein in urine
- CT/MRI evidence of lytic bone lesions
- increase in BM plasma cells on BM aspirate or trephine biopsy
Diagnosis of multiple myeloma:
-requires 2 out of 3 diagnostic features to be present, what are these?
- paraproteinaemia on serum protein immunofixation / Bence Jones protein in urine
- CT/MRI evidence of lytic bone lesions
- increase in BM plasma cells on BM aspirate or trephine biopsy
Diagnosing MM requires 2+/3 of the following:
-monoclonal protein band in serum/urine electrophoresis
-CT/MRI evidence of lytic bone lesions
-increase in BM plasma cells on BM aspirate or trephine biopsy
-end organ damage evidence e.g. renal insufficiency, highCa2+, anaemia
What other investigations should be sent for multiple myeloma
- blood count (may show anaemia, thrombocytopenia and leukopenia)
- ESR is often high, blood film shows rouleux
- serum biochem may show renal failure and hypercalcaemia
(NB: serum beta2-microglobulin and albumin are used in prognosis)
How is multiple myeloma managed? What does supportive treatment entail? Prognosis
- supportive care (correct anaemia w transfusion/erythropoietin, treat infections promptly, treat bone pain with radiotherapy or high dose dexamethasone)
- treat AKI/hypercalcaemia with adequate hydration
- bisphosphonates to reduce progression of bone disease
- treat hyperviscosity by plasmapheresis + systemic therapy
- chemotherapy, autologous stem cell transplant. An alkylator e.g. cyclophosphamide, melphalan steroid and novel agent e.g. bortezomib/lenalidomide.
- survival 5-10yrs (incurable currently)
Name 2 complications post splenectomy:
In conjunction with this name 2 preventative measures that are given:
- thrombophilia in the short term (mobilise early post-op)
- acute gastric dilatation
- sepsis/infection esp. streptococcus pneumoniae, H. influenzae and meningococci
- therefore give Pneumococcus, Hib, menC and flu vaccine before elective splenectomy
- lifelong penicillin V 500mg twice daily (erythromycin if penicillin allergic)
What 3 histological findings are characteristic on blood film following a splenectomy?
-clue: 2 bodies, one shape of cell
- Howell-Jolly Bodies
- Pappenheimer Bodies
- Target Cells
There is a pentad of symptoms in thrombotic thrombocytopenia purpura (TTP) , name 3 of them:
- microangiopathic haemolytic anaemia
- thrombocytopenia
- AKI
- neuro sx: headache, palsies, seizure, confusion, coma
- fever
What causes thrombotic thrombocytopenia purpura (TTP)
clue: brother
- congenital deficiency or acquired antibodies against ADAMTS13 protease (which normally cleaves multimers of vWF)
- large vWF multimers causes platelet aggregation and fibrin deposition in small vessels –> a multisystem thrombotic microangiopathy
