•Cation exchange resins, for example, sodium polystyrene sulfonate (Kayexalate or Resonium) 0.5–1 g/kg/day, by enema and orally if possible, or calcium polystyrene sulfonate (1 g/kg/day, by enema and orally if possible in a ratio of 1:1)

•Collaboration with nephrology department; consider peritoneal dialysis or hemodialysis if abovementioned treatment is not successful

18.4Hypercalcemia

18.4.1 General

• Rare in children with malignant tumors. Mainly seen in children with acute lymphoblastic leukemia, NHL, skeletal metastases (e.g., NHL), Ewing sarcoma, rhabdomyosarcoma, neuroblastoma

18.4.2 Diagnosis

•Symptoms: Anorexia, nausea, vomiting, polyuria, constipation, followed by dehydration

•Other symptoms include polydipsia, obstipation, ileus, bradycardia, arrhythmia, muscular weakness, lethargy, depression, fatigue, stupor, coma

•Pathophysiology of oncological hypercalcemia: humoral, osteolytic, and vitamin D-mediated hypercalcemia

•Factors interfering with serum calcium: thiazide diuretics, antacids with calcium carbonate, lithium, hypervitaminosis (A or D), renal disorders, hyperparathyroidism, adrenal gland insufficiency, fractures, immobilization, oral contraceptives

•Laboratory analysis: serum calcium and ionized calcium, magnesium, phosphorus, sodium, potassium, protein, albumin, alkaline phosphatase, urea, creatinine

•Urine (spot test): calcium, creatinine, (calculate calcium, creatinine, and phosphorus reabsorption)

•Radiology: ultrasonography of kidneys, to rule out nephrocalcinosis and lithiasis

18.4.3 Treatment

•Consider treatment when calcium concentration is more than 2.8 mmol/l. Calcium concentration more than 3.5 mmol/l needs immediate treatment

•Forced diuresis with hydration with NaCl 0.9% (10–20 ml/kg/h for 1–4 h) Furosemide 1–2 mg/kg i.v. every 2–6 h

•Monitoring: sodium, potassium, excretion of sodium and potassium, urine volume, substitute losses (because of dehydration)

•Consider glucocorticoids (e.g., oral prednisone 2 mg/kg/day)

•Consider calcitonin 2–4 IU/kg every 6–12 h (effects within hours)

•Consider i.v. mithramycin or pamidronate (tumor-induced hypercalcemia)