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 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 to 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)