haematology Flashcards
which infection is commonly known to precipitate haemolytic crisis
parvovirus (Erythema infectiosum)
slapped cheek syndrome
Mx acute haemolytic crisis
supportive treatment +/- transfusion
long term MX of hereditary spherocytosis
folate replacement
splenectomy
classic presentations of the hereditary causes of haemolysis
neonatal jaundice
infection/ drugs precipitate haemolysis
gallstones
+/- splenomegaly depending on whether it is due to intra or extravascular haemolysis
red blood cell transfusion thresholds
patients without acute coronary syndrome, transfusion threshold is 70g/L with post-transfusion target 70-90g/L
patients WITH acute coronary syndrome, transfusion threshold is 80g/L with post-transfusion target 80-100g/L
*does not apply to ongoing major haemorrhage or chronic anaemia requiring transfusion
why do we irradiate blood products?
deplete T-lymphocytes
avoid transfusion related graft vs host disease
most common genetic bleeding disorder and its inheritance pattern
presentation
Ix.
von willebrand disease
autosomal dominant
Ix. prolonged PT, APTT, low factor 8 and normal platelets. defective platelet aggregation with ristocetin
presentation of VWF disease
mucosal bleeding (gums, nose) + menorrhagia
Mx. of vwf disease
- tranexamic acid for mild bleeding
- desmopressin raises levels of vWF
- factor 8 concentrate
1 unit of RBCs
how quickly must be given after removal from fridge and over what timespan
non-urgent transfusions, transfuse 1 unit of RBCs over 90-120 minutes. Give within 4 hours of removal from fridge
G6PD deficiency drugs causing haemolysis
aspirin, antimalarials, sulph-group drugs
mx of patients at high risk of neutropenia.
which patients are at high risk of neutropenia and neutropenic sepsis
filgrastim (granulocyte-colony stimulating factor)
risk factors: elderly specific ca: non-hodgkins, ALL previous neutropenic episodes combo chemo + radiotherapy
** odly not given to patients with myeloid malignancies as can precipitate them further
mx febrile neutropenia
piperacillin with tazopbactam
prophylaxis chemotherapy induced neutropenia
fluorquinolone
Histology of hodgkin’s lymphoma
4 types
***nodular sclerosing - women, good prognosis
mixed cellularity
lymphocyte predominant - best prognosis
lymphocyte depleted - rare, worst prognosis
man with CLL comes in with fever, and swollen lymph nodes
richter transformation into high grade non-hodgkin’s lymphoma
causes of iron deficiency
intake - poor diet
absorption - coeliac disease
use - children, pregnancy
loss - menstruation, GI bleeding
Well’s score criteria
1 point for each
risk factors: active cancer (<6mo), paralysis, bedridden (surgery), previous documented DVT
signs: local leg tenderness, swollen, calf swelling >3cm compared to other, unilateral pitting oedema, non-varicose distended leg veins
- 2 if an alternative diagnosis is AS LIKELY
DVT likely wells score and what do you do
DVT likely (2 or more)
USS within 4 hours → if it positive then treat, if it is negative do a D-dimer to confirm
if can’t do USS within 4 hours, do a D-dimer and treat with DOAC (rivaroxaban) and do the USS within 24hrs
if USS negative, D dimer positive, stop DOAC and repeat USS one week later
DVT UNlikely wells score and what do you do
DVT unlikely (1 point or less)
do a D dimer within 4 hours, if positive then do USS
within 4 hours, if not possible within 4, give DOAC and do USS within 24
if can’t do a D dimer within 4 hours, give a DOAC until you can
what cases would you NOT give a DOAC for VTE treatment?
what do you give?
severe renal impairment GFR<15/min
antiphospholipid syndrome
LMWH, unfractionated heparin or VKA
duration of VTE anticoagulation
everyone for 3 months
+ 0 months if provoked eg. surgery
+ 3 months if unprovoked VTE – absence of bleeding risk factors
+ 1 - 3 months if cancer – a grey area and patient specific
reversal agent for DOACs eg. rivaroxaban
andexanet alfa
causes of neutropenia
Infection - viral (HIV, EBV< hepatitis), severe sepsis
Inflammation - rheumatological conditions, rheumatoid arthritis (Felty’s hypersplenism), SLE
Malignancy - aplastic anaemia, myelodysplastic malignancies
drugs - clozapine
what is the philadelphia translocation and which disease is it associated with?
t(9;22) BCR-ABL gene – excessive tyrosine kinase activity
chronic myeloid leukaemia
translocation in acute promyelocytic leukaemia
t(15;17)
most common leukaemia in adults in western world and its presentation
B cell chronic lymphocytic leukaemia
asymptomatic (leukocytosis on incidental blood film) +/- generalised lymphadenopathy and hepatosplenomegaly
blood film findings CLL
smudge/smear cells
which DOAC is preferred for renal impairment patients
apixaban - minimal renal drug clearance
reversal agent for dabigatran
idarucizumab
dabigatran is a direct thrombin inhibitor
reversal of heparin
protamine
beta thalassemia trait blood findings
no changes to blood film
mildly anaemic
quite low MCV
disproportionate microcytosis with mild anemia is the key
inheritance pattern of sickle cell anemia
pathophysiology
autosomal recessive
codon 6 of the beta Hb chain substitution of glutamate for valine
this change means that in deoxygenated state the HbS molecule polymerises and the RBC sickles
heterozygous patients only sickle if severely hypoxic
homozygous patients sickle more easily
sickled cells haemolyse and sequestrate causing infarction
Jehova’s witness needing surgery with high risk of blood loss
cell saver device – collects blood and reinfuses
Warfarin reversal
- stop warfarin
- urgent — human prothrombin complex (1hour action but 6 hour half life) + vitamin K
- vit K (4-24 hours oral vs. IV)
- FFP
reversal of anticoagulation (warfarin) or major haemorrhage
prothrombin complex concentrate
cryoprecipitate vs FFP when to give
FFP - clinically significant but no major haemorhage. prolonged PT or APTT
cryoprecipitate - clinically significant but no major haemorhage. low fibrinogen. blood coagulopathies (vwf, haemophilias)
