Transcript Thrombocytopenia

Allen Chang, PGY2
5/18/15
Learning Objectives
 Understand the mechanisms causing
thrombocytopenia
 Learn the workup of thrombocytopenia
 Understand when to transfuse platelets
Case 1
A 24 year old woman is evaluated for a 1 day history of
epistaxis and a new onset rash on her shins. Last week, her
menses were abnormally heavy. Vital signs are normal. She
has bruising over the shins and wrists and a petechial rash
over the shins and abdomen.
 Laboratory studies:
 Hemoglobin
 MCV
 Platelet count
11.9 g/dL
85 fl
8,000/uL
WHAT IS GOING ON? DOCTOR! DO WE TRANSFUSE?
Thrombocytopenia
 Thrombocytopenia is a platelet count less than
150,000.
 There may be no symptoms and low platelets may
simply found on routine CBC OR patients may bleed
profusely
 Platelet counts at 20-50 are associated with
mucocutaneous bleeding and less than 10 is associated
with spontaneous intracerebral hemorrhage.
Classification of Thrombocytopenia
 Increased Destruction
 ITP, HIT, DIC, TTP/HUS, Medications
 Decreased Production
 Vitamin B12 / Folate deficiency, Bone marrow failure or invasion,
aplastic anemia, Fanconi anemia, Medications
 Sequestration
 Hypersplenism (from Cirrhosis, heart failure, hepatic venous
thrombosis, malignancy, infections)
Pseudothrombocytopenia
 How do you eliminate pseudothrombocytopenia?
 Recheck CBC in an EDTA tube
 Platelet clumping tricks the automated platelet
counters into thinking that there are fewer platelets.
Medications Commonly Associated
with Thrombocytopenia
 Penicillins
 Carbamazepine
 Gold compounds
 Heparin
 Phenytoin
 Rifampin
 Sulfonamides
 Vancomycin
 Valproic Acid
Roberto Stasi Hematology 2012;2012:191-197
INDICATIONS FOR
TRANSFUSION
PLATELET COUNT
Stable, no bleeding
<10
Stable, non bleeding and
temperature of > 100.4
<20
Major surgery or invasive
procedure, no active bleeding
< 50
Ocular surgery or neurosurgery, no
active bleeding
< 100
Case 1 Revisited
A 24 year old woman is evaluated for a 1 day history of epistaxis and
a new onset rash on her shins. Last week, her menses were
abnormally heavy. Vital signs are normal. She has bruising over
the shins and wrists and a petechial rash over the shins and
abdomen.
 Laboratory studies:
 Hemoglobin
 MCV
 Platelet count
 Do we transfuse?
11.9 g/dL
85 fl
8,000/uL
Take Home Points
 Thrombocytopenia is caused by sequestration,
increased destruction or increased production
 Rule out Pseudothrombocytopenia by repeating a CBC in
an EDTA tube.
 Magic numbers are <10, <20 and <50
 Transfuse regardless if platelets less than 10
 Transfuse temperature is >100.4 if platelets are less than 20
 Transfuse if patient is to have a surgery or procedure if
platelets are less than 50
References
 ACP, MKSAP 16 Hematology/Oncology
 George, J. ITP in adults: initial treatment and prognosis, UpToDate, Waltham,
MA 2015
 Liumbruno G, Bennardello F, Lattanzio A, Piccoli P, Rossetti G; Italian Society
of Transfusion Medicine and Immunohaematology (SIMTI) Work Group.
Recommendations for the transfusion of plasma and platelets. Blood Transfus.
2009;7(2):132–150.
 Stasi, R; How to approach thrombocytopenia. American Society of Hematology
Education Book. 2012: 2012. 191-197