Hematology and Oncology Emergencies
The hematology/oncology patient can decompensate in ways that look like common childhood illness, so build a habit of asking about the underlying diagnosis and recent therapy. In sickle cell disease, know the five crises: vaso-occlusive pain, acute chest syndrome, splenic sequestration, aplastic crisis, and stroke. Any child with sickle cell disease and a fever at or above 38.5°C (101.3°F) needs blood cultures and empiric antibiotics promptly, because functional asplenia makes sepsis rapid and lethal. Acute chest syndrome (new infiltrate, fever, chest pain, hypoxemia) is a leading cause of death - treat with oxygen, antibiotics, and transfusion. Splenic sequestration shows a falling hemoglobin with an enlarging spleen; aplastic crisis from parvovirus shows a low reticulocyte count. Stroke requires emergent transfusion, and transcranial Doppler screening is the preventive standard.
Bleeding disorders and platelet problems
Hemophilia treatment is factor replacement; avoid intramuscular injections, aspirin, and NSAIDs, and hold pressure longer. Immune thrombocytopenia typically shows petechiae and bruising in a well-appearing child with an isolated low platelet count and no other cytopenias.
Oncology emergencies
Febrile neutropenia (absolute neutrophil count under 500 with fever) requires empiric broad-spectrum antibiotics within 60 minutes. Tumor lysis syndrome produces hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia - look for tetany, seizures, and arrhythmias; treat with aggressive hydration and urate-lowering therapy. Transfusion reactions require stopping the infusion immediately and maintaining access.
Rule of thumb: fever in a neutropenic or asplenic child is a sepsis emergency - antibiotics go in before the workup is finished.