4. Overview ooff hheemmoossttaassiiss
There are four distinct phases in hemostasis
which is geared to stop blood loss.
•First the damaged blood vessel narrows
(vasoconstriction) to reduce the blood flow and
therefore blood loss. This happens almost
immediately once the blood vessel is
damaged.
5. • Second the platelets in the blood
(small particles of larger cells)
adheres to the lining of the
damaged blood vessel and stick to
each other to plug the site of blood
loss (platelet plug). This is known
as the platelet phase and occurs
within seconds of a tear in the
blood vessel.
6. • The third is the clotting phase or coagulation
phase in which the various clotting factors
activate each other (coagulation cascade) to
turn the liquid blood components into a more
semi-solid to solid mass (blood clot). The clot
also retracts to draw the damaged ends of the
blood vessel together and form a tight seal
and this is sometimes mentioned as separate
phase known as clot retraction.
7. • The last phase involves the
removal of the clot once the blood
vessel is completely repaired. The
clot may be dissolved (fibrinolysis)
or sometimes contributes to scar
formation at the site (fibrosis).
Monagle P, Barnes C, Ignjatovic V, et al. . 2006
9. CCooaagguullaattiioonn ccaassccaaddee
Kinins HMW Kininogen
Kallikrein Contact Activation
XII Prekallikrein
XIIa
XIa XI
IXa Ca++ IX
VIIIa VIII
Ca++
Phospholipid
Intrinsic Pathway
Xa X
Va V
Ca++
Phospholipid XIII
II IIa
XIIa
Fibrinogen Fibrin XIII
Common Pathway
VII VIIa
Ca++
Tissue Factor
Extrinsic Pathway
10. Clinical approach in mmaakkiinngg aa ddiiaaggnnoossiiss
1-HISTORY
Clinical evaluation of a bleeding patient begins with
taking a careful history, taking into account the
child's age, sex, clinical presentation, past history,
and family history.
the history also should include complete details as to
the type of bleeding, location, degree of symptoms,
nature of provoking injuries, and whether such
injuries are consistent with the child’s development
and level of activity
(( KKhhaaiirr aanndd LLiieessnneerr..,,22000066 ))
11. Age and sex of the patient
• An inherited bleeding disorder should be
strongly considered when the onset of
bleeding manifestations occurs in infancy or
early childhood and is associated with a
positive family history.
•However, a negative family history does
not exclude an inherited coagulation
disorder, as up to one-third of patients with
hemophilia have a negative family history .
12. Family history
The family history is helpful in formulating a possible diagnosis
of an inherited disorder of coagulation.
The presence of bleeding manifestations only in male siblings
and maternal uncles is suggestive of X-linked recessive
inheritance, such as that seen in hemophilia A or B.
In contrast, in autosomal dominant traits such as hereditary
hemorrhagic telangiectasia (Osler-Weber-Rendu disease), an
accurate pedigree will show affected individuals of both sexes
for several generations.
In autosomal recessive disorders, such as severe forms of the
rarer coagulation factor deficiencies (eg, factor VII or factor XI
deficiency), the family history may be negative; consanguinity
increases the probability of such disorders.
13. Medication
• specific information should be sought about the
ingestion of aspirin, aspirin-containing over-the-counter
medications, and other non-steroidal anti-inflammatory
drugs such as ibuprofen or naproxen.
Such drugs impair platelet function and may
exacerbate an underlying coagulation disorder .
•In addition, use of such drugs within one to two
weeks of platelet function testing may cause
abnormalities, which may lead to further expensive
and unnecessary studies.
14. Is a bleeding tendency present or
not ?
While assessing a patient, one has to keep in
mind that not all bleeding episodes suggest
a generalized bleeding disorder.
For example, epistaxis may be caused by
rhinitis, trauma, superficial vessels, or dry
air,
and abnormal post-surgical bleeding (eg,
tonsillectomy) may be caused by surgical
trauma rather than a generalized bleeding
disorder.
15. 22-- EExxaammiinnaattiioonn
General stability, vitals signs, evidence of chronic disease,
evidence of malignancy.
Skin stigmata :
> PETICHEAE
> ECHYMOSES
>JOINT BLEED &DEEPSEATED HEMATOMAS
> HEPATOSPLENOMEGALY
> SIGNIFICANT LYMPHADENOPATHY
> ACTIVE AND PLAYFUL VS. ILL LOOKING
> DYSMORPHIC FEATURES
> CAFÉ-AU-LAIT SPOTS
>TELANGIECATIC VESSELS
>HEMANGIOMAS
17. • The usual initial screening tests
include
- Quantitation of platelets
- examination of the peripheral blood smear
- prothrombin time/international normalized
ratio (PT/INR)
- activated partial thromboplastin time
(aPTT)
- the fibrinogen activity level.
18. • Proper collection of the blood sample is
essential for interpreting the results of clotting
tests.
• Blood for coagulation tests should not be
drawn from an existing heparinized indwelling
line.
• Coagulation tests are performed on blood
anticoagulated with a solution of sodium
citrate in a ratio of nine parts of blood to one
part of citrate.
20. The following conditions are cchhaarraacctteerriizzeedd bbyy
pprroolloonnggeedd aaPPTTTT::
●HHeemmoopphhiilliiaa –– HHeemmoopphhiilliiaa AA ((ffaaccttoorr VVIIIIII
ddeeffiicciieennccyy)) iiss tthhee mmoosstt ccoommmmoonn iinnhheerriitteedd
ddiissoorrddeerr yyiieellddiinngg aa ssiiggnniiffiiccaannttllyy pprroolloonnggeedd
aaPPTTTT..
●FFaaccttoorr XXII ddeeffiicciieennccyy –– FFaaccttoorr XXII ddeeffiicciieennccyy
iiss sseeeenn mmoorree ccoommmmoonnllyy iinn AAsshhkkeennaazzii
JJeewwss aanndd pprreesseennttss wwiitthh aa vvaarriiaabbllee hhiissttoorryy
ooff bblleeeeddiinngg
21. ●Lupus anticoagulants – Lupus anticoagulants
are acquired inhibitors that may produce a
prolonged aPTT. They are commonly seen in
children, frequently associated with recent
infections, particularly viral infections, and
usually are transient.
●Deficiencies of factor XII, high molecular
weight kininogen (HMWK), and prekallikrein
usually are asymptomatic and not associated
with clinical bleeding.
●Heparin contamination – and is likely if the
thrombin time (TT) is prolonged
22. 2- Prolonged PT and normal aPTT
- An isolated prolongation of the PT is
characteristic of inherited or acquired
factor VII deficiency.
- Inherited factor VII deficiency displays
phenotypic and molecular heterogeneity,
whereas acquired factor VII inhibitors are
very rare occurrences during childhood.
23. 3- Prolonged PT and aPTT
AA-- WWeellll cchhiilldd
Prolongation of both PT and aPTT in a bleeding
child who is otherwise well indicates an
inherited disorder within the common pathway
(factor X, V, II (prothrombin) or fibrinogen;
these deficiencies are rare) or an acquired
disorder involving multiple pathways
25. B- NORMAL INITIAL CCOOAAGGUULLAATTIIOONN
TTEESSTTSS
NNoorrmmaall ppllaatteelleett ccoouunntt
In children with bleeding symptoms and an initial
laboratory screen with a normal platelet count and
initial coagulation screening tests, possible diagnoses
include
11-- vvoonn WWiilllleebbrraanndd ddiisseeaassee ((vvWWDD))
22-- ssoommee ccaasseess ooff hheemmoopphhiilliiaa
33-- ffaaccttoorr XXIIIIII ddeeffiicciieennccyy
44-- vvaassccuullaarr aabbnnoorrmmaalliittyy
55-- aa ffiibbrriinnoollyyttiicc ddiissoorrddeerr..
26. 6- platelet ffuunnccttiioonn ddiissoorrddeerr
Classic inherited disorders of platelet function are
relatively rare and include:
●Glanzmann thrombasthenia, which is characterized
by a defect in the platelet
glycoprotein IIb/IIIa complex
●Bernard-Soulier syndrome, which is characterized by
a defect in one of the components of the platelet
glycoprotein Ib-IX-V complex, giant platelets.
●Storage pool diseases, including Chediak-Higashi
syndrome, Hermansky-Pudlak syndrome, Wiscott-
Aldrich syndrome, and thrombocytopenia with absent
radius syndrome. Park CH, Seo JY, Kim HJ, et al . 2010
28. 1- Hemophilia
Hemophilia is a blood clotting disease that
arises due to the deficiency of one of the clotting
factors.
- It is the most common of the bleeding/clotting
disorders.
- About 85% of hemophilics have a deficiency of
Factor VIII,
while the other 15% have a deficiency of Factor
IX.
A very rare type of hemophilia involves Factor
XI
29. - Types of Hemophilia
Hemophilia A
In this type of hemophilia, there is a deficiency
in Factor VIII. This clotting factor is
manufactured in the liver and the endothelial
cells lining the blood vessel, circulates in the
blood by binding to von Willebrand factor
(vWF) and is activated by thrombin. Once
activated Factor VIIIa then works with Factor
IX, calcium and phospholipids to activate
Factor X.
30. Hemophilia B
This type of hemophilia is due to a
deficiency in Factor IX. It is also known
as Christmas Disease. Factor IX
circulates in the blood stream in an
inactive form and depends on Factor XI
to activate it (IXa). Once activated it
works with Factor VIII, calcium and
phospholipids to activate Factor X.
31. Hemophilia C
A third type of hemophilia known as
hemophilia C is a mild form of hemophilia. It
is not as common as other blood clotting
disorders and is mainly seen in certain
ethnic groups. This type of hemophilia is
due to a deficiency of Factor XI and
prevents the activation of sufficient
quantities of Factor IX
32. females can hhaavvee hheemmoopphhiilliiaa ::
• Lyonization of the normal X chromosome
• Turner syndrome ( XO)
• Father with hemophilia/ mom as a carrier
• vW type 2 N ( Normandy)
HHEEMMOOPPHHIILLIIAA SSEEVVEERRIITTYY LLEEVVEELLSS
• Severe <1% activity level - Spontaneous bleeds
• Moderate 1 to 5% activity --Trauma/surgery bleeds
,Occasional joint bleeds
• Mild 5 to 30% activity - Major trauma/surgery ,
Rare joint bleeds
33. Treatment ooff hheemmoopphhiilliiaa ::
11 uu//kkgg rraaiisseess FFVVIIIIII lleevveellss 22%% ,, 11//22 lliiffee :: 1122 hhrrss
11 uu//kkgg rraaiisseess FFIIXX lleevveellss 11 %% ,, 11//22 lliiffee 2200--2244 hhrrss
MMiinnoorr BBlleeeeddiinngg EEppiissooddeess ::--
• Early joint bleeds
• Soft tissue & muscle bleeds
• Nose & gum bleeding not responding to local
measures
- 40 - 50% correction
– FVIII : 25 units / kg
– FIX : 50 units / kg
34. Major Bleeding EEppiissooddeess ::--
• Advanced soft tissue & muscle bleeds
• Head & neck injuries
• Gastrointestinal bleeding
• Advanced joint bleeding
• 80 – 100 % correction
• FVIII : 50 units / kg
• FIX : 100 units / kg
PPlluummmmeerr EESS aanndd CCrraarryy SSEE .. 22001133
37. 1- von Willebrand ddiisseeaassee ((vvWWDD))
- A mild bleeding disorder caused by a
deficiency or malfunctioning of von
Willebrand factor (vWF).
- It is a fairly common inherited bleeding
disorder that affects both males and females.
- It may be autosomal dominant (types 1, 2A,
2B, 2M), autosomal recessive (type 2N) or
compound heterozygosity (type 3).
38. • von Willebrand factor Binds to platelet
receptor GP Ib and to subendothelial
structures such as collagen serving as
bridge between platelets and
subendothelium in damaged vessels
• Acts as bridge between adjacent platelets
in vessels with high shear (arterioles)
forming small platelet aggregates
• Binds to circulating factor VIII protecting it
and prolonging FVIII t1/2 in the circulation
from 2 to 8-12 hours.
39. - Types of von Willebrand Disease
Type 1 is the most common and in there is a partial quantitative
deficiency in von Willebrand factor (vWF)
Type 2 the quantity of vWF may be normal but the factor may be
defective.
• Type 2A is the most common subtype with mutations in
platelet binding.
• Type 2B is where there is a mutation of the platelet
glycoprotein 1b (Gp1b) binding site.
• Type 2N is where there is a mutation in the factor VIII binding
site.
• Type 2M is where there is abnormalities in platelet binding.
Type 3 is a severe deficiency (quantitative) in von Willebrand
factor. It leads to a severe bleeding disorder but is rarely seen.
40. Acquired von Willebrand ddiisseeaassee oorr vvoonn
WWiilllleebbrraanndd ssyynnddrroommee iiss dduuee ttoo oonnee ooff
tthhee ffoolllloowwiinngg ::
• antibody against vWF
• degradation of vWF
• absorption of vWF by malignant cells or
activated platelet
This is seen with Wilm’s tumor, multiple
myeloma, systemic lupus erythematosus (SLE)
and leukemia .
41. - Treatment of von Willebrand DDiisseeaassee ::
Treatment is not necessary in most cases since
the disease is so mild. Although there is
prolonged bleeding, clotting and subsequently
cessation of bleeding will eventually occur.
42. • Desmopressin (DDAVP) is usually
administered via a nasal spray.
• Parenteral administration (injections) may
only be necessary in severe cases but has
limited benefit in type 3 vWD.
• Infusions of factor VIII or von Willebrand
factor (vWF) may be considered in patients
who do not respond to DDAVP or type 3
vWD.
• Anti-fibrinolytic agents delays the
breakdown of blood clots.
44. 33-- tthhrroommbbooccyyttooppeenniiaa
TThhrroommbbooccyyttooppeenniiaa ppuurrppuurraa ((TTPP)) iiss aa
bblleeeeddiinngg ddiissoorrddeerr cchhaarraacctteerriizzeedd bbyy aa
vveerryy llooww nnuummbbeerr ooff ppllaatteelleettss
((tthhrroommbbooccyytteess)) cciirrccuullaattiinngg iinn tthhee bblloooodd
ssttrreeaamm..
Causes and Types of
Thrombocytopenia :
45. 1- Idiopathic Thrombocytopenia Purpura (ITP)
- This type of thrombocytopenia occurs for no known reason.
Antibodies formed by the body against the platelets (auto-antibodies)
attach to the platelet membranes.
- This “marks” the platelets for destruction by the body’s
immune system particularly within the spleen.
- In idiopathic thrombocytopenia purpura (ITP) the body still
produces a normal level of platelets but these are rapidly
removed from the circulation thereby leading to a platelet
deficiency.
- This type of thrombocytopenia is seen with immune
dysfunction often associated with diseases like HIV infection
and autoimmune disorders.
- It may also occur in pregnancy and with the use of certain
drugs like heparin.
Provan D and Stasi R . 2010
46. 2- Heparin-induced tthhrroommbbooccyyttooppeenniiaa ((HHIITT))
- may arise after the administration of unfractionated
heparin.
- This drug is an anticoagulant and when derived from
natural sources (unfractionated) compared to
synthetic formulas of lower molecular weight, the
effects can sometimes be unpredictable.
- Antibodies are then formed against the heparin and
certain platelet proteins which then attach to and
activate the platelets.
- These platelets are then removed from the
circulation thereby leading to a deficiency of
platelets.
47. 3- Thrombotic Thrombocytopenia
Purpura (TTP)
In this type of thrombocytopenia, there is
sudden formation of blood clots throughout
the body even though there is no
hemorrhage (bleeding) requiring clot
formation.
In the process, the circulating platelet levels
drop because the body uses the platelets to
form these clots.
48. 4- Hemolytic-Uremic SSyynnddrroommee ((HHUUSS))
Toxins produced in the gut by bacteria like E.coli
are absorbed into the bloodstream where it
triggers the rapid destruction of red blood cells
and platelets. The patient usually has
gastroentritis associated with E.coli infection and
this conditions may also occur with other
infections like Shigellosis
OOtthheerr CCaauusseess ooff LLooww PPllaatteelleett CCoouunntt
• AAllccoohhooll aabbuussee
• LLeeuukkeemmiiaa
• LLyymmpphhoommaa
• AAppllaassttiicc aanneemmiiaa aanndd ootthheerr ttyyppeess ooff aanneemmiiaa
49. 4- vitamin K deficiency
causes a mild bleeding disorder due to a deficiency of clotting
factors VII, IX, X and prothrombin (factor II). The liver
utilizes vitamin K to synthesize these clotting factors.
5- Factor I deficiency
is due to a lack (afibrinogenemia), deficiency
(hypofibrinogenemia) or defective functioning
(dysfibrinogenemia) of fibrinogen.
6- Blood vessel wall abnormalities
where there is a weakening of the wall which will easily tear or
rupture. These conditions are rare and includes :
• Hereditary hemorrhagic telangiectasia
• Ehlers-Danlos disease
• Scurvy
Lusher J, Pipe SW, Alexander S 2010