Haematology Flashcards
What are the features of warm AIHA?
37 degree IgG extravascular haemolytic \+ve Coombs test Blood film - spherocytes
What are the causes of warm AIHA?
Mainly primary idiopathic Lymphoma CLL SLE Methyldopa
What are the features of cold AIHA?
<37 degrees IgM intravascular haemolytic \+ve Coombs Often with Raynauds
Causes cold AIHA?
primary idiopathic lymphoma infections EBV mycoplasma
Management warm AIHA?
Steroids
splenectomy
Immunosuppression
Management cold AIHA?
Treat underlying condition
avoid the cold
chlorambucil
Causes of inherited haemolytic anaemia?
membrane - hereditary spherocytosis
cytoplasm - G6PD deficiency
haemoglobin - SCD or thalassaemia
Causes of acquired haemolytic anaemia?
immune mediated:
cold/warm
alloimmune
non immune mediated: infection (malaria) paroxysmal nocturnal haemoglobunuria prosthetic heart valves MAHA - adenocarcinoma - HUS - TTP spherocytosis -ve coombs test
what is the HUS triad?
MAHA
thrombocytopenia
AKI
(e.coli toxin 0157)
how does adenocarcinoma cause haemolytic anaemia?
releases granules into circulation
pro-coagulant and active coag cascade
platelet activation, fibrin deposition, degranulation
red cell fragmentation due to low grade DIC
bleeding (low platelet and coagulation factor deficiency)
TTP pentad?
MAHA thrombocytopenia AKI neurological impairment fever
what causes TTP?
Deficiency in VWF cleaving protease -> high VWF -> cheese wire in blood vessels
Autoimmune: anti-glycoprotein 2b/3a antibody
Mx TTP?
plasma exchange
NOT STEROIDS
Findings on TLS Ix?
hyperkalaemia
hyperphosphataemia
hypocalcaemia
+ clinical features
lab >=2 of: within 7 days chemo or 3 days before Uric acid >475 umol/l or >25% increase K>6 mmol/l or 25% increase PO4 >1.125 or 25% increase Ca <1.75 or 25% decrease
clinical:
>=1.5x ULN creatinine
cardiac arrhythmia or sudden death
seizure
Mx TLS?
prophylaxis:
high risk: IV allopurinol or IV rasburicase
low risk: PO allopurinol
Indications for packed RBC transfusion?
no ACS - maintain >70 x10^9/L
ACS - maintain >80
Indications for platelet transfusion?
pre-procedure - maintain >50 x10^9
50-75 x 10^9 if high risk of bleeding
>100 if surgery at critical site e.g. the eye
contraindications for platelet transfusion?
bone marrow failure (chronic) ITP
heparin induced thrombocytopenia ITP
Inherited thrombophilias?
factor V Leiden (hetero/homo) - hetero most common (activated protein C resistance) Protein C deficiency Protein S deficiency Antithrombin III deficiency Prothrombin gene mutation
Acquired thrombophilias?
APLS
COCP
what is the most common bleeding disorder?
VWD
what is heparin induced thrombocytopenia?
AB form again PF4 and heparin after 5-10days of treatment with heparin
prothrombotic condition
S/S of HIT?
> 50% reduction in platelets
thrombosis
skin allergy
Mx HIT?
direct thrombin inhibitor
danaparoid
signs of transfusion reaction?
Fever low BP vomiting headache chestpain rigors dyspneoa urticaria collapse flushing pain at transfusion site itching
What are some causes of acute transfusion reactions? <24h
acute haemolytic reactions (ABO incompatibility) allergic/anaphylactic infection (bacterial) febrile non-haemolytic reaction respiratory (TACO, TRALI)
what are some causes of delayed transfuion reactions >24h?
delayed type haemolytic transfusion reactions infection (viral, malaria, vCJD) TA-GvHD (1-2w after transfusion) post transfusion purpura iron overload
Aetiology of febrile non-haemolytic transfusion reaction (FNHTR)?
release of cytokines from white cells during storage
S/S of FNHTR?
mild to mod reaction
small rise in temperature
chills, rigors
Mx FNHTR?
stop/slow transfusion
paracetamol
Aetiology allergic/anaphylactic transfusion reactions?
more common with FFP (proteins in plasma)
worst reaction if IgA deficient as anti-IgA abs in recipient attack the donor
S/S allergic/anaphylactic transfusion reactions?
mild itchy rash
anaphylaxis
Mx allergic/anaphylactic transfusion reactions?
stop/slow transfusion
mild (IV antihistamine)
anaphylaxis (adrenaline, ABC)
Aetiology ABO incompatibility/wrong blood?
IgM mediated intravascular haemolysis
S/S (acute haemolytic transfusion) ABO incompatibility/wrong blood?
septic looking restless chest/loin pain fever vomiting flushing haemoglobinuria
Ix ABO incompatibility/wrong blood?
FBC, XM, DAT
Mx ABO incompatibility/wrong blood?
stop transfusion
fluid resuscitation
Aetiology bacterial contamination transfusion reaction?
bacterial endotoxin build up in bag
platelets>RBC> FFP