Pediatric emergency medicine trisk 560

for a given clinical situation are limited in children due to the rarity of this diagnosis. An
individualized treatment plan for patients with additional thrombotic risk factors is
appropriate.

DISORDERS OF HEMOSTASIS
Goals of Treatment
Achieving hemostasis in the setting of spontaneous or traumatic bleeding is paramount.
Additionally, taking appropriate preemptive steps prior to procedural intervention for
patients with ongoing or potential hemorrhage is critical.
CLINICAL PEARLS AND PITFALLS
Factor replacement is the primary goal in any hemophilia patient with
suspected or known bleeding.
Measured levels of factor VIII and factor IX typically predict clinical severity;
however, levels for other factor deficiencies including VII and XI do not
reliably correlate with bleeding phenotype.

Current Evidence
The most common inherited bleeding disorders are VWD, factor VIII deficiency
(hemophilia A), and factor IX deficiency (hemophilia B). These bleeding disorders are
reviewed in more detail in the following sections. Other rare inherited disorders include
isolated defects or deficiencies in specific factor proteins which contribute to the
initiation of clot formation such as factor II, factor V, factor VII, factor X, factor XI,
proteins responsible for clot stabilization such as factor XIII, and proteins which counter
the fibrinolytic pathway such as plasminogen activator inhibitor type-1 (PAI-1). Each of
these deficiencies has a clinically variable phenotype. This combined with their rarity
has hindered the development of clinical practice guidelines for rare bleeding disorders.
Once a diagnosis is made, therapeutic decisions must be tailored to the individual
patient based on bleeding severity and location. Acquired defects of hemostasis are
uncommon in the pediatric population, but consider these disorders in the setting of
acute onset of an unexpected bleeding episode in the absence of any personal or family
history of bleeding. Among the more common acquired causes are DIC, which can arise

in the setting of sepsis or severe trauma, uremia and drug-induced platelet dysfunction,
and decreased factor synthesis due to liver disease and cholestasis.

Clinical Considerations
Clinical Recognition
Severe congenital disorders of hemostasis typically present during infancy. Mild and
moderate disorders may go undetected until later childhood or even adulthood when


patients sustain a challenge that exceeds the capability of their hemostatic system, such
as major surgery or trauma, invasive dental procedure or extraction, or menarche.
Emergency physicians may encounter patients who are referred for an abnormal
coagulation laboratory result obtained by a primary care physician, often because of an
expressed concern for bleeding or easy bruising, or because of a family history of a
bleeding disorder. Consider underlying coagulation disorders in patients who return with
postoperative and traumatic bleeding that seems out of proportion to the clinical
situation. Infants may present to the ED with prolonged bleeding from the site of
circumcision or the umbilical stump. Older children may present with a pattern of
mucosal bleeding including epistaxis or menorrhagia, or with deep muscle or joint
bleeds, usually trauma associated.
Triage
If a child presents with active bleeding, initial assessment should focus on the site and
severity of hemorrhage and prioritize therapeutic interventions to achieve hemostasis.
Evidence of hemodynamic compromise should prompt rapid resuscitation efforts to
reestablish circulating volume. Consider the need for prompt surgical involvement if
clinically indicated.
Clinical Assessment
A detailed history of the patient’s prior bleeding events and a thorough family history
are necessary to determine the level of concern for an underlying bleeding disorder.
Pertinent history includes:

Are bleeding episodes related to mild–moderate trauma or procedures or do they occur
spontaneously?
Is the bleeding typically a mucocutaneous pattern (e.g., epistaxis, oral bleeding,
petechiae, easy bruising, GI bleeding, or menorrhagia)?
Is there bleeding into the deep muscles or joints?
Is there a history of poor wound healing?
Are bleeding episodes more likely to occur hours versus days after a procedure or
injury?
Additionally, family history of responses to hemostatic challenges may suggest an
inherited defect of hemostasis. Mucocutaneous bleeding is usually associated with
defects of primary hemostasis such as platelet count (see section on thrombocytopenia
above) or dysfunction, or VWD. Bleeding into deep muscles or joints, especially when
spontaneous, is characteristic of hemophilia. Poor wound healing or delayed bleeding
following a procedure has been described with factor XI, factor XIII, and PAI-1
deficiencies. A physical examination should focus on findings of active or recent
bleeding including a careful HEENT and dermatologic examination.


Diagnostic Testing
The initial screening laboratories to investigate for hemostatic abnormalities should
include CBC, examination of the peripheral blood smear, prothrombin time (PT), and
activated partial thromboplastin time (aPTT), von Willebrand panel, thrombin time
(TT), and fibrinogen. Save blood for additional assays of specific factors. An approach
to initial interpretation of these tests is presented in Figure 93.5 . The CBC reveals the
platelet count, aids in recognition of associated anemia resulting from bleeding, and
reveals white blood cell count abnormalities that may suggest underlying sepsis or
malignancy. Review of a peripheral blood smear enables verification of the platelet
count and also allows for visualization of platelet morphology, such as the presence of
normal granulation necessary for platelet function. Other elements seen on the
peripheral smear may also yield clues to the underlying diagnosis such as RBC

fragments seen with microangiopathic coagulopathy or peripheral blasts suggestive of
an underlying hematologic malignancy. The PT evaluates factors II, V, VII, X and
fibrinogen, while aPTT evaluates factors II, V, VIII, IX, X, XI, and fibrinogen. Factor
XII deficiency will also prolong the aPTT but is not associated with a bleeding
phenotype. These initial tests can help emergency physicians narrow the differential
diagnosis, but more extensive evaluation is usually needed to make a final diagnosis.
Such tests may include a von Willebrand panel, assays for specific factor levels,
inhibitor assays, platelet function (aggregometry) studies; these tests are almost never
available in real time for clinical use in an emergency department. Fortunately, initial
steps in management are not hindered by the lack of a precise diagnosis. It is important
to note that proper collection of the blood sample for these specialized coagulation
studies is paramount for accurate results. Samples that are drawn through heparinized
indwelling catheters, overshaken, or not promptly processed often yield erroneous
results.

Management
Establishment of a specific hemostatic disorder diagnosis should not take precedence
over the timely management of a serious bleeding episode. Where applicable, use local
measures such as pressure dressings and nasal packing, as well as other adjuncts such as
estrogen with or without progesterone in the case of menorrhagia. In cases of trauma in
the setting of underlying disorder of hemostasis, multidisciplinary management is
appropriate. Agents useful for achieving hemostasis are reviewed in Table 93.2 .
Specific management strategies for treating VWD and hemophilia A and hemophilia B
are detailed below.
Rare Inherited Coagulation Factor Deficiencies
There are no clinical practice guidelines for managing the rare, inherited coagulation
factor deficiencies, in part because of small patient numbers and in part due to the
clinical heterogeneity of these disorders. For patients with known deficiencies,

implementation of their bleeding management plan or consultation with their
hematologist is advised. For severe bleeding episodes, major trauma, or an emergent
operative procedure, replacement of the missing factor protein is generally advised. For
factors VII and XIII, recombinant products are available; plasma-derived protein
concentrates are also available for these factors and for factor XI in some countries.
Cryoprecipitate contains concentrated quantities of factor XIII, fibrinogen, factor VIII,
and VWF. Fresh-frozen plasma may be used for any factor deficiency; however, large
volumes of product are often required to achieve hemostatic levels. If patients have
primarily mucosal bleeding, antifibrinolytic therapies may provide sufficient hemostasis.

FIGURE 93.5 Approach to diagnosis of a bleeding disorder.

Disseminated Intravascular Coagulopathy
Treatment of the inciting disease process is critical. Therapy to correct the coagulopathy
is appropriate in an actively bleeding patient; however, it provides only a temporary
solution. Infusion of platelets, fresh-frozen plasma, and cryoprecipitate (see Table 93.2 )
may be trialed to improve hemostasis; however, replacement therapy should not be
continued if there is no clinical benefit. The role of heparin therapy for DIC remains
controversial and should only be initiated in consultation with a hematologist. The use
of agents such as antithrombin, rFVIIa, and direct thrombin inhibitors has been reported
in the adult literature, but there are presently no data to support their use in the pediatric
population with DIC.