Immune Thrombocytopenia (ITP) in Emergency Medicine Treatment & Management

Prehospital care focuses on the ABCs (airway, breathing, circulation), which include providing oxygen if necessary, controlling severe hemorrhage, and initiating intravenous (IV) fluids to maintain hemodynamic stability. Airway control may be necessary for a large intracranial hemorrhage.

Emergency medical services providers should be aware of the potential for serious bleeding complications in patients with immune thrombocytopenia (ITP).

The patient with known ITP who has bleeding that poses a threat to life, limb, or sight requires treatment to improve hemostasis along with conventional critical care interventions. Intravenous immunoglobulin (IVIG), which has the most rapid onset of action, should be considered along with high-dose parenteral glucocorticoids. In patients who require a more rapid rise in their platelet count, case reports suggest that the following treatments may be useful ^[16] :

• Platelet transfusions, possibly in conjunction with a continuous infusion of IVIG
• Recombinant factor VIIa (however, note the risk of thrombosis)
• Antifibrinolytic agents (aminocaproic acid, tranexamic acid) 

Platelet transfusion is indicated for controlling severe hemorrhage. Send a blood specimen to the lab for type and screen in case platelet transfusion is necessary. Platelet survival is increased if the platelets are transfused immediately after IVIG infusion. A consultation with a hematologist may be required to make a decision regarding the transfusion of platelets.

Guidelines for transfusion dosage are as follows:

• 6-8 U of platelet concentrate, or 1 U/10 kg
• 1 U of platelets to increase count of a 70-kg adult by 5-10,000/mm ³ and an 18-kg child by 20,000/mm ³

Splenectomy is reserved for patients in whom medical therapy fails. Fortunately, thrombopoietin receptor agonists can often provide effective second-line management of patients with persistently low platelet counts and bleeding, thus averting surgery. ^[17]  When medical therapy fails in a patient with life-threatening bleeding, emergent splenectomy (with or without IVIG and/or corticosteroids and usually with platelet transfusions) may be considered as a heroic measure. ^[16]

In patients without life-threatening complications, focus ED care on confirming the diagnosis, if possible, and initiating therapy as needed. Most patients with undiagnosed thrombocytopenia and purpura will need admission for further evaluation and treatment, since ITP is a diagnosis of exclusion.

Transfer may be necessary under the following conditions:

• A hematologist is not available.
• Blood bank support is insufficient.
• A higher level of intensive care is needed.

Inpatient Care

Inpatient care includes the following:

• Rule out other potential causes of thrombocytopenia.
• Observe for life-threatening bleeding. Emergency splenectomy may be necessary if severe bleeding complications due to thrombocytopenia do not respond to medical therapy.
• Consult with a hematologist, as further treatments (eg, steroids, IVIG, platelet transfusion, thrombopoietin receptor analogs in chronic ITP) may be indicated.

Consult a hematologist for assistance in confirming the diagnosis or, in the patient with known ITP, arranging disposition and follow-up care, if appropriate.

Consult a neurosurgeon for intracranial hemorrhage. Consultation by other surgical specialists may be required for extensive hemorrhage at other sites.

Treatment in pediatric patients

American Society of Hematology (ASH) guidelines recommend that in children who have no bleeding, or only mild bleeding (ie, skin manifestations only, such as bruising and petechiae), regardless of the platelet count, management should be with observation alone. For pediatric patients requiring treatment, ASH suggests a short course of corticosteroids for first-line treatment rather than IVIG or anti-D immunoglobulin. ^[18]

For children or adolescents with ITP who have significant ongoing bleeding despite treatment with IVIG, RhIG, or conventional doses of corticosteroids, the ASH suggests a thrombopoietin receptor agonist (TPO-RA) rather than rituximab or splenectomy as second-line treatment. Rituximab may also be considered as an alternative to splenectomy. ^[18]

Treatment in adults

A 2010 international consensus report advised that treatment for ITP is rarely indicated in adult patients with platelet counts above 50×10⁹/L, in the absence of the following ^[19] :

• Bleeding due to platelet dysfunction or another hemostatic defect
• Trauma
• Surgery
• Clearly identified comorbidities for bleeding
• Mandated anticoagulation therapy
• Profession or lifestyle that predisposes the patient to trauma

In adults, treatment is recommended for a platelet count < 30×10⁹/L. The ASH recommends that if treatment is needed, shorter courses of corticosteroids (≤6 weeks) are preferred over prolonged courses (>6 weeks including treatment and taper) as first-line treatment. The guidelines suggest either prednisone (0.5-2.0 mg/kg per day) or dexamethasone (40 mg per day for 4 days) as the type of corticosteroid for initial therapy.  ^[18]

In adults with ITP lasting ≥3 months who are corticosteroid-dependent or have no response to corticosteroids, the ASH guidelines suggest either splenectomy or a TPO-RA. In adults who are going to be treated with aTPO-RA, either eltrombopag or romiplostim is suggested by the ASH guidelines. ASH also suggests rituximab over splenectomy. ^[18]

For adults with ITP, ASH guidelines recommend treating newly diagnosed patients whose platelet count is less than 30 × 10⁹/L. Recommendations for first-line treatment include the following ^{[18, 16]} :

• Shorter courses of ≤ 6 weeks are preferred over prolonged courses (>6 weeks including treatment and taper) of corticosteroids
• Either prednisone (0.5-2.0 mg/kg per day) or dexamethasone (40 mg per day for 4 days) as the type of corticosteroid for initial therapy. 
• IVIg may be used with corticosteroids when a more rapid increase in platelet count is required
• Either IVIg or anti-D (in appropriate patients) be used if corticosteroids are contraindicated

Recommended second-line treatments for cases that do not respond to corticosteroids, or recur afterward, are as follows, in order of preference ^[18] :

• A TPO-RA (eltrombopag, avatrombopag, romiplostim)
• Rituximab
• Splenectomy

Increasingly, clinicians are trying TPO-RAs before referring patients for splenectomy.  According to published data, 25–30% of patients who are treated with TPO-RAs have a sustained response after stopping the drug. The mechanism for these sustained responses is not known. Spontaneous remission is unlikely as an explanation, as the patients in reported studies had all received several prior treatments and had severe, prolonged thrombocytopenia. ^[20]

Close follow-up care with a hematologist is required. Elective splenectomy may be necessary if medical therapy fails.