6.3 Sickle Cell Disease Crisis & Pediatric Oncologic Emergencies

Overview of Pediatric Hematologic & Oncologic Emergencies

Hematologic and oncologic emergencies in pediatric patients represent rapid, life-threatening complications resulting from underlying hemoglobinopathies or malignant cellular proliferations and their aggressive treatments. Pediatric emergency nurses must maintain high vigilance when evaluating children with Sickle Cell Disease (SCD) presenting with acute pain, fever, or respiratory distress, as well as pediatric cancer patients presenting with febrile neutropenia, Tumor Lysis Syndrome (TLS), or mediastinal mass syndrome. Timely, protocol-driven emergency management directly impacts survival and long-term morbidity.

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Sickle Cell Disease (SCD) Crises

Sickle Cell Disease is an autosomal recessive disorder characterized by mutant hemoglobin S (HbS). Under conditions of hypoxia, acidosis, dehydration, or hypothermia, HbS polymerizes, transforming red blood cells (RBCs) into rigid, sickle-shaped cells that cause microvascular occlusion, tissue ischemia, end-organ infarction, and hemolysis.

+-----------------------------------------------------------------------------------------+
|                              SICKLE CELL DISEASE CRISES COMPARISON                      |
+-----------------------+-----------------------------+-----------------------------------+
|  VASO-OCCLUSIVE CRISIS|    ACUTE CHEST SYNDROME     |   SPLENIC SEQUESTRATION CRISIS    |
+-----------------------+-----------------------------+-----------------------------------+
| Severe bone/joint pain| Fever, chest pain, dyspnea, | Sudden abdominal pain, pallor,    |
| Ischemia, dactylitis  | new X-ray pulmonary infiltrate| rapid splenomegaly, severe anemia |
| Treatment: Opioids,   | Treatment: Broad-spectrum   | Treatment: Urgent PRBC transfusion|
| IV hydration, warmth  | antibiotics, oxygen, PRBCs  | volume expansion, surgery consult |
+-----------------------+-----------------------------+-----------------------------------+

1. Vaso-Occlusive Pain Crisis (VOC)

VOC is the most common emergency ED presentation in SCD. Sickled RBCs occlude microvascular beds, producing severe ischemic pain in bones, joints, and abdomen, or dactylitis (painful hand-foot swelling in infants).

• Multimodal Analgesia: Administer rapid IV opioid analgesia (Morphine 0.1 mg/kg or Hydromorphone 0.015–0.02 mg/kg) within 30 minutes of ED arrival. Place on scheduled opioid dosing or Patient-Controlled Analgesia (PCA), combined with IV NSAIDs (Ketorolac 0.5 mg/kg).
• Hydration: Administer IV fluid hydration at 1.25 to 1.5 times maintenance using 0.45% NS to decrease blood viscosity. Avoid hypertonic fluids and fluid overload.
• Supportive Care: Apply warm compresses to painful areas. NEVER apply cold packs or ice, as local vasoconstriction triggers sickling. Supplemental oxygen is indicated only if SpO2 < 92% (hyperoxia suppresses erythropoiesis).

2. Acute Chest Syndrome (ACS)

ACS is the leading cause of death in SCD. It is defined as a new pulmonary infiltrate on chest radiograph accompanied by at least one clinical feature: fever (≥ 38.5°C), chest pain, tachypnea, wheezing, cough, or hypoxemia.

• Emergency Protocol:
  1. Administer empirical IV broad-spectrum antibiotics (Ceftriaxone plus Azithromycin) to cover Streptococcus pneumoniae and atypical pathogens (Mycoplasma/Chlamydia).
  2. Initiate aggressive incentive spirometry (10 breaths every hour while awake) to prevent atelectasis.
  3. Prepare for simple packed red blood cell (PRBC) transfusion (target Hb 10 g/dL) or exchange transfusion if severe respiratory failure occurs (targeting HbS < 30%).

3. Splenic Sequestration Crisis

Occurs primarily in infants and young children (before splenic autoinfarction occurs). Sickled RBCs become trapped in the spleen, causing rapid splenic enlargement and massive blood pooling.

• Clinical Signs: Sudden onset of abdominal pain, left upper quadrant tenderness, profound pallor, tachycardia, hypovolemic shock, and a precipitously falling hemoglobin level (> 2 g/dL drop below baseline) with elevated reticulocyte count.
• Treatment: Immediate fluid resuscitation with Normal Saline boluses and urgent PRBC transfusion to restore intravascular volume and oxygen-carrying capacity.

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Pediatric Oncologic Emergencies

1. Febrile Neutropenia Emergency Protocol

Febrile neutropenia is a life-threatening medical emergency in pediatric oncology patients receiving chemotherapy.

• Diagnostic Definitions:
  • Fever: A single oral/axillary/central temperature ≥ 38.3°C (101°F) OR sustained temperature ≥ 38.0°C (100.4°F) for over 1 hour.
  • Neutropenia: Absolute Neutrophil Count (ANC) < 500 /mcL, or ANC < 1000 /mcL with expected decline to < 500 /mcL.
  • ANC Calculation Formula: $\text{ANC} = \text{WBC} \times (\frac{% \text{segmented neutrophils} + % \text{bands}}{100})$.

2. Tumor Lysis Syndrome (TLS)

TLS arises from rapid, massive destruction of malignant cells (frequently in ALL or high-grade Burkitt lymphoma) releasing intracellular contents into the bloodstream.

Diagnostic Laboratory Quadrant

• Hyperkalemia (Early & most lethal; causes cardiac dysrhythmias).
• Hyperphosphatemia (Binds calcium, causing secondary hypocalcemia).
• Hyperuricemia (Uric acid precipitates in renal tubules, causing acute kidney injury).
• Hypocalcemia (Results in tetany, Chvostek/Trousseau signs, seizures, QTc prolongation).

Emergency Interventions

• Aggressive IV Hydration: Administer IV fluids at 2 to 3 L/m²/day (or 1.5 to 2 times maintenance) without added potassium to preserve renal clearance.
• Rasburicase: Administer Rasburicase (0.15 to 0.2 mg/kg IV), a recombinant urate oxidase enzyme that rapidly converts uric acid into soluble allantoin. (Note: Screen for G6PD deficiency before administration to avoid severe hemolysis).
• Allopurinol: Used for low-risk TLS to inhibit xanthine oxidase and prevent new uric acid synthesis.

3. Superior Vena Cava (SVC) / Mediastinal Mass Syndrome

Anterior mediastinal masses (e.g., T-cell ALL, Non-Hodgkin Lymphoma) compress the trachea and superior vena cava, creating acute airway and vascular compromise.

• Clinical Presentation: Facial and upper extremity edema, neck vein distension (plethora), stridor, wheezing, orthopnea, and syncope when supine.
• CRITICAL AIRWAY WARNING: NEVER SEDATE OR PARALYZE a pediatric patient with a mediastinal mass in the supine position. Loss of intercostal smooth muscle tone leads to complete, irreversible tracheobronchial collapse and fatal cardiac arrest.
• Management: Maintain patient in a comfortable upright or sitting position, provide humidified oxygen, avoid invasive airway procedures until oncology/cardiac surgery is present, and prepare for emergent radiation therapy or corticosteroid administration.