Bleeding disorders Flashcards
normal platelet count
150-450k
50-100k platelet
high bleeding time
30-50k platelet
bruising with minor trauma
10-30k platelet
spontaneous bruising
menorrhagia
spontaneous bruising
gum and gut bleeding
nose bleeds
brain bleeds
thrombocytopenia
low platelets
GP1b
platelet receptor for vWF binding
GP2b3a
platelet receptor for fibrinogen binding
ITP
immune thrombocytopenia purpura
IgG from splenic plasma cells against platelet antigens
splenic macrophages clear antibody covered platelets
symptoms of ITP
petechiae
ecchymosis
treatment of ITP
corticosteroids IVIG splectomy TPO rituximab
acute ITP
kids
post viral infection or immunization
self limited
chronic ITP
female
NAT
neonatal alloimmune thrombocytopenia
IgG alloantibodies (HPA-1a) from mom cross placenta and coat fetal platelets
occurs in first child- mom produces antibodies to foreign fetal platelets
NAT treatment
corticosteroids
IVIG
platelet transfusion
labs for ITP
decreased platelets
normal PT/PTT
increased megakaryocytes
HIT
heparin induced thrombocytopenia
antibodies against factor 4 produced after exposure to heparin
leads to platelet activation and thrombosis
type 1 HIT
non immune mild thrombocytopenia rapid onset self resolving asymptomatic
type 2 HIT
immune severe thrmobocytopenia onset 4-14d stop heparin thromboembolic complications
labs for HIT
platelet activation tests
HIT antibody detection
treatment of HIT
stop heparin
thrombin inhibitors
drug induced thrombosis
antibodies made against platelets after exposure to a specific drugs
lead to widespread platelet activation and thrombosis
TTP
thrombotic thrombocytopenic purport
ADAMTS13 protease inactivated by IgG leading to large aggregates of vWF that activate platelets
TTP pentad
thrombocytopenia microangiopathic hemolytic anemia renal dysfunction neurologic disturbances fever
TTP thrombcytopenia
large platelets
increased megakaryocytes
TTP MHA
shistocytes
increased LDH
increased unconjugated bilirubin
TTP renal dysfunction
increased creatinine
TTP labs
normal PT and PTT
typical HUS
hemolytic uremic syndrome
microangiopathic hemolytic anemia + thrmobicytopenia
caused by enterohemorrhagic E coli Shigella-like toxins that disrupt endothelial lining leading to platelet activation
in kids
atypical HUS
noninfective- inherited or sporadic mutations leading to excessive complement activation
chronic, recurring
leads to end stage renal failure
differentiating factor between TTP and HUS
HUS has prominent renal failure
TTP only has mildly elevated creatinine kinase
difference between atypical and typical HUS treatmetn
atypical treated with eculizmab
PFA
platelet function analyzer
platelets exposed to platelet agonists and shear rate to determine inherited platelet function disorders, vWD, and meds affecting function
Glanzmann thrombocytopenia
GP2b/3a defect/deficiency
no aggregation to ADP, collagen, or epinephrine
most common inherited platelet function defect
bernard-souiler syndrome
GP1b defect/deficiency
no aggregation to ristocetin
giant platelets and mild thrombocytopenia
platelet against for aspirin
arachidonic acid
platelet against for clopidogrel (P2Y12 receptor)
ADP
platelet against for vWD
ristocetin
platelet against for bernard Soulier
ristocetin
routine lab tests for hemostasis
platelet count PT PTT fibrinogen D-dimer
specialized lab tests for hemostasis
bleeding time/PFA vWF testing platelet aggregation factor assays thrombin time
intrinsic pathway
PTT
elevated by heparin
F8, 9, 11 defieiencies
extrinsic pathway
PT
elevated by warfarin
F7 defiency
role of vitamin K
factors 2, 7, 9 10
what increases first in vitamin K deficiency and why
PT- factor 7 has shortest half life
coumadin reversal
FFP
prothrombin complex concentrates
von willenbrand disease
most common AD bleeding disorder
chromosome 12
variable bleeding- mucus membranes, wounds, menorrhagia, epistaxis
type 1 vwd
decreased vwf levels
mild/variable bleeding
type 3 vwd
VERY decreased vwf levels
hemarthrosis
type 2 vwd
abnormal vwf that can’t bind factor 8 or GP1b receptor
vwd labs
normal PTT abnormal PFA normal platelet count low ristocetin test decreased F8 activity WVF antigen activity- type 1, 3
vwd treatment
vwf replacement
DDAVP- stimulates release
anti-fibrinolytic
hemophilia A
factor 8 deficiency
treated with factor 8
hemophilia B
factor 9 decency
treated with factor 9
PTT in hemophila
increased
corrected with mixing studies
factor 8 inhibitor
alloantibody developed against factor 8 in hemophilia A
treated by giving F8 or recombinant 7a
bethesda titer
determines strength of factor 8 inhibitor
low- give 8
high- give 7a
DIC platelet count
decreased
DIC D-dimer
increase
DIC PT
increase
DIC PTT
increase
DIC thrombin time
increase
DIC fibrinogen
decrease
