Heme-Onc Emergencies

Tumor Lysis Syndrome

• Hyperkalemia
• Hyperphosphatemia (and consequent hypocalcemia)
• Hyperuricemia
• Renal Failure
• Most common with Burkitt's and T cell lymphoma/leukemia
• May occur at presentation or up to 1 week after starting therapy
• Prevention is paramount


What to do:

• Check lysis labs every 4-6 hours
• IV fluids at 2 to 4 times maintenance
• D5 1/4 NS + 40 mEq NaHCO₃.  No potassium in the IVF.  May need to reduce the glucose concentration because of high infusion rate and/or steroid-induced hyperglycemia.
• Adjust bicarbonate to keep the urine pH between 7.0 and 7.5.  Too low precipitates urate crystals; too high precipitates limestone, xanthine, and hypoxanthine.
• Patients must save *all* urine output (dip all urines).
• Keep the urine specific gravity less than 1.010.
• Make sure that IF fluids start in the ED (call in advance!)
• If the patient becomes puffy, use diuretics to increase urine flow.  Do not decrease the IV infusion rate.
• Allopurinol
• Amphogel prn for hyperphosphatemia
• Kayexelate, glucose/insulin for hyperkalemia.  Avoid enemas if patient is neutropenic.  Check EKG.
• Avoid calcium infusions unless the patient is symptomatic from hypocalcemia.  Treat hyperphosphatemia first.
• Dialysis may be necessary in some cases, but recovery is usually complete.  Notify the renal team in advance, and call the PICU for probable transfer and placement of dialysis catheter.

Hyperleukocytosis

• Occurs in both ALL and AML.  Much more worrisome in AML because of size, stickiness, and granule content of blasts.
• May cause CNS thrombosis or hemorrhage.
• Patients may present with hypoxia, confusion, headache, lethargy, coma.
• no clear WBC indication for pheresis, but generally pheresis is used for WBC > 400,000 in ALL, and WBC > 150,000-200,000 in AML.  Pheresis is also indicated for symptomatic patients.


What to do:

• Start hydration immediately.
• Avoid transfusions of pRBCs, unless essential, because of risk of hyperviscosity.  Transfuse platelets if less than 20,000 to prevent hemorrhage.
• Call pheresis team if indicated, but anticipate several hours set up equipment.
• Call PICU team for transfer and for placement of dialysis catheter.

Superior Mediastinal Syndrome

• Usually associated with superior vena cava syndrome in children.
• Most common causes include lymphoma, neuroblastoma, germ cell tumor, and Ewing's sarcoma.  SVC syndrome may also occur with central line thrombosis.  Make sure to get a CXR for any new patient with leukemia.
• Patients present with dyspnea, stridor, cough, wheezing, chest pain, swelling of the face or arms, sitting forwards or orthopnea, anxiety, confusion, headache, or syncope.


What to do:
 

• Make the diagnosis ASAP
• Look away from the mediastinal mass, e.g., superficial nodes, pleural effusion, bone marrow, chemistry tests (AFP, hCG for germ cell tumors; HVA, VMA for neuroblastoma).
• Use minimal sedation.  Avoid general anaesthesia.
• Obtain echocardiogram, PFTs.
• Emergent therapy.  if possible, wait for diagnosis.
• XRT (200 cGy) to paratracheal region can relieve symptoms but spare some tissue for diagnosis (though scatter effect can be significant).  Disadvantage is possible need for rehabilitation from post-radiation tracheal swelling.
• Steroids can be started as soon as diagnostic tissue is obtained, and relief is usually rapid.

Increased intracranial pressure

• Patients present with headache, confusion, lethargy, vomiting, seizures, diplopia, ataxia.
• Focal neurological signs may be present and related to the tumor location.
• Cushing's triad: bradycardia, hypertension, agonal respirations.


What to do:
 

• CT scan
• Call neurology and neurosurgery
• Decrease IV fluid rate
• Dexamethasone (0.5 - 1 mg/kg)
• Other options:  mannitol, acetazolamide, hyperventilation, antiepileptic drugs, platelet transfusion (goal > 50,000)

Spinal Cord Compression

• Patients present with back pain, weakness, sensory loss, incontinence
• Most common diagnoses are neuroblastoma, Ewing's sarcoma, lymphoma, and CNS tumors


What to do:
 

• Call neurology and neurosurgery
• Dexamethasone 1 mg/kg
• MRI
• laminectomy if diagnosis is not known
• XRT if diagnosis is known and tumor is radiation-sensitive
• Chemotherapy if diagnosis is known

Fever and Neutropenia

• Fever is defined as one temperature => 38.5C (101.3F) or three temperatures => 38.0C (100.4F) in 24 hours.
• Neutropenia is defined as an ANC < 500 or <1000 and falling.
• Patients with newly diagnoses leukemia are considered functionally neutropenic, regardless of their ANC.
• Bone marrow transplant patients in the first 6-9 months after transplant, and any patients with chronic graft-versus host disease are also considered functionally neutropenic.


What to do:
 

• All patients, except for those on palliative care, must go to an ED immediately, either the central ED or an ED local to them.  During the day time, they may come the hematology clinic.
• Obtain blood cultures from all lumens of all central lines.  Peripheral blood cultures are not necessary as part of the initial evaluation if the patient has a central line.
• CXR as needed.
• Start antibiotics as soon as the cultures have been obtained:
• Fever and central line without neutropenia:  Oxacillin 37.5 mg/kg q 6 hours and gentamicin 7 mg/kg q 24 hours.
• Fever and neutropenia (with/without central line):  Oxacillin, gentamicin, and ceftazidime 50 mg/kg q 8 hours.
• Vancomycin should be used for patients with AML and immediately following bone marrow transplant.
• Patients must receive all antibiotics in the ED prior to admission.
• Some patients in the clinic with fever and a central line who are not neutropenic may be given antibiotics and sent home, but the same patients who come to the ED overnight should be admitted for observation.
• Oral therapy for fever and neutropenia should only be given as part of an active study.