Pediatric emergency medicine trisk 679
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SECTION II: MANAGEMENT OF COMPLICATIONS ASSOCIATED
WITH CANCER AND CANCER THERAPY
This section focuses on the complications of cancer treatment that are likely to lead
to an ED visit for care. The systems-based review of management below focuses on
the initial care of the patient and does not address the more detailed evaluation and
management needed subsequently. Complications of specific chemotherapeutic
agents are listed in Table 98.8 .
HEMATOLOGIC COMPLICATIONS OF CANCER TREATMENT
Goals of Treatment
Cytopenias are common in both newly diagnosed cancer patients as well as those
undergoing active therapy, and a high index of suspicion should be maintained for
all of these patients.
CLINICAL PEARLS AND PITFALLS
Patients receiving chemotherapy should be presumed to be neutropenic
and isolated from the potential sources of infection that exist in the ED as
soon as possible.
Patients with thrombocytopenia requiring procedures may benefit from
platelet infusion during the procedure itself.
Current Evidence
Many chemotherapeutics cause reversible myelosuppression. Neutrophils have a
very short half-life and thus their numbers may drop rapidly after initiation of
treatment, but also may recover quickly. Platelets have a slightly longer half-life and
thus tend to drop and recover slightly more slowly. Because red blood cell half-life
is over 100 days, chemotherapy effects on red cells tend to be more chronic than
acute. The nadir blood counts usually occur 7 to 10 days after start of treatment and
recovery usually occurs 10 to 14 days after start of treatment. The pattern of
myelosuppression differs by chemotherapy regimen. For example, most solid tumor
regimens allow for complete recovery within 10 to 14 days, while acute
myelogenous leukemia regimens may delay recovery until 4 to 6 weeks after
treatment. Even within a given regimen, there is variation both among patients and
among cycles for one patient. In general, recovery is slower for patients who have
already received many cycles of chemotherapy, whose course has been complicated
by infection, or whose bone marrow has been extensively replaced by tumor.
Radiation to the marrow cavity, especially including the spine or pelvis, can also
cause myelosuppression during treatment and/or delayed recovery after treatment. In
addition, cytopenias are a common finding in patients with newly diagnosed
leukemia.
Significant neutropenia is usually defined as an ANC below 500 cells/μL. The
ANC is calculated by multiplying the percentage of WBCs that are neutrophils or
bands by the total WBC count. Patients with an ANC below 500 have an increased
risk of bacterial infections due to insufficient numbers of phagocytic cells to fight
bacteria. This risk increases dramatically when the ANC is below 100. Patients may
develop infections with bacteria that are not pathogens in normal hosts. The risk of
fungal infections increases with prolonged (more than 21 days) and severe (ANC
below 500) neutropenia. The infectious risks of neutropenia are increased by a
number of contributing factors. Indwelling foreign bodies such as central lines,
ventriculoperitoneal shunts, and bone allografts provide a foreign surface that
increases the likelihood of infection and the difficulty of treatment. The mucosal
injury that typically accompanies myelosuppression increases the risk of bacteria
entering the circulation through translocation across disrupted mucosal surfaces.
Immunosuppression decreases phagocytic function as well.
TABLE 98.8
SIGNIFICANT ACUTE COMPLICATIONS OF SELECTED DRUGS
Drug
Complications
Asparaginase
• Allergy
• Hemorrhage
• Deep and superficial vein thrombosis (cerebral sinus venous
thrombosis)
• Hyperglycemia
• Pulmonary fibrosis and/or pneumonitis
Bleomycin
Anthracyclines
(doxorubicin,
daunorubicin)
• Cardiomyopathy
Corticosteroids
• Avascular necrosis
• Hyperglycemia
Cyclophosphamide • SIADH
• Hemorrhagic cystitis
Cyclosporine
• Hypomagnesemia and seizures
Cytarabine
• Neurotoxicity (cerebellar dysfunction, onset within hours of
treatment with high doses)
• Eye pain, tearing, sensitivity to light and blurred vision
(high doses)
• Seizures (high doses)
• Erythroderma, especially palmar, with resulting
desquamation (high doses)
Dactinomycin
• Venoocclusive disease of the liver
Etoposide
• Hypotension (during infusion)
Ifosfamide
• Salt wasting
• Neurotoxicity (confusion, inappropriate laughter,
somnolence, psychosis)
• Renal injury manifested as Fanconi syndrome with proximal
tubular dysfunction and wasting of phosphate, glucose,
potassium, and bicarbonate
• Hemorrhagic cystitis
Methotrexate
• Seizures
• Elevated transaminases (1–3 days after high-dose
administration)
