Chapter 85. Hematologic-Oncologic Emergencies in Children

Childhood cancer is a leading cause of death in children, but with improvements in management and outcomes, many patients with new, active, or treated malignancies present to the ED. This chapter will cover the most common pediatric malignancies and hematologic issues. More information on malignancy-related complications is provided in Chapter 139 and hemophilia and Von Willebrand Disease are discussed in detail in Chapter 135.

Acute Lymphoblastic Leukemia (ALL) is the most common pediatric malignancy, with a peak incidence between 3 to 5 years of age and a 75% to 80% 5-year survival.

Clinical Features

Patients can present with any of the following signs or symptoms of bone marrow infiltration: pallor, fatigue, easy bruising, fever, or bone pain. Many have hepatomegaly or splenomegaly. Rarely, acute myelogenous leukemia (AML) can present with gingival hyperplasia or subcutaneous masses (chloromas).

Diagnosis and Differential

The complete blood count (CBC) with manual differential is the most useful test, though leukocytosis and blasts may be absent early in the disease process, requiring close follow-up of patients with insidious complaints such as bone pain. WBC counts below 4000/mL3, mild anemia, and mild thrombocytopenia should raise suspicion in these cases. Abnormalities of 2 or more cell lines make leukemia more likely. If the CBC is concerning for acute leukemia, obtain a chest radiograph (for mediastinal mass); electrolytes with creatinine, uric acid, and phosphate (for evidence of tumor lysis); liver function tests and lactate dehydrogenase, PT/PTT (looking for disseminated intravascular coagulation); type and screen if anemic; and blood and urine cultures if febrile.

The differential diagnosis is extensive depending on the patient's presenting symptom. Aplastic anemia and viral infections can cause bone marrow suppression; rheumatologic diseases can overlap with symptoms and findings of leukemia; and idiopathic immune thrombocytopenia can be difficult to differentiate, though classically involves isolated destruction of the platelets without affecting other cell lines.

Emergency Department Care and Disposition

Chemotherapy need not be initiated immediately in most cases. ED care is directed at potential complications and symptoms.

1. Anemia:

   1. Irradiated, leukodepleted packed red blood cells (PRBCs) (10 mL/kg) for life-threatening hemorrhage or hemolysis.

   2. If no hemorrhage or hemolysis, nonemergent transfusions can be given to keep hemoglobin (Hb) > 8 grams/dL. This should be done in coordination with oncologist.

2. Thrombocytopenia:

   1. Platelets (10 mL/kg) for life-threatening hemorrhage, consumption, or urgent need for invasive procedure (eg, lumbar puncture).

   2. If no urgent indication exists, nonemergent transfusions can given to keep platelets >10 000/mL3. This does not need to be done in the ED.

3. Infection: Fever and neutropenia typically become an issue after the initiation of chemotherapy. However, granulocyte function is impaired in newly presenting leukemics, and fever or suspicion of infection in a new leukemic should be treated emergently with broad spectrum antibiotics. In children with known neutropenia from treatment, consider unusual infections ...