Pediatric emergency medicine trisk 686

known or not) when starting antibiotics and other medications that are renally excreted GENITOURINARY COMPLICATIONS OF CANCER TREATMENT The most common form of bladder injury in cancer patients is hemorrhagic cystitis, a potential complication of exposure to cyclophosphamide or ifosfamide Prevention of drug-induced hematuria usually includes hydration, frequent voiding, and administration of mesna (2-mercaptoethane sulfonate sodium), a drug that binds the toxic metabolite Manifestations include dysuria, suprapubic pain, and microscopic or gross hematuria with onset within 24 hours of drug administration Other causes of toxicity to the GU tract include infection, bladder radiation, tumor resection, or ongoing presence of tumor in the GU tract If a patient is complaining of bladder-related symptoms or the urinalysis shows evidence of hematuria, the oncology-specific history should be reviewed to help develop an appropriate differential diagnosis in addition to the usual causes (such as infection) that would be considered in a patient without cancer Initial management should include initiation of one and one-half times to twice maintenance hydration and frequent voiding Laboratory evaluation should include a urinalysis, CBC to look for anemia or thrombocytopenia, and coagulation studies Any contribution from coagulopathy and/or thrombocytopenia should be corrected If severe bleeding or bladder outlet obstruction from clots occurs, a urologist should be consulted A bladder catheter large enough to be used for irrigation should be placed and bladder washing initiated Packed red blood cell transfusion may be needed In very rare cases, bleeding can be life threatening and bladder sclerosis is indicated Mesna has no utility once the offending drug has cleared from the system Pain management with oxybutynin chloride and narcotics should be initiated as needed SKIN COMPLICATIONS OF CANCER TREATMENT Various cancer treatments are known to have cutaneous toxicities Radiation induces dermatitis in the treatment field that can range from mild to severe based on the total dose and any concurrent radiation sensitizers The presentation may vary from a mild erythroderma, similar to sunburn, to severe desquamation in the treatment field Any topical treatment must be prescribed in conjunction with the treating radiation oncologist because certain topical agents may increase the radiation dose to the skin Drug rashes are very common in oncology patients Because patients tend to be on many drugs at one time, it may be difficult to identify the specific culprit Management of a drug reaction is not unique in oncology patients However, consultation with the oncologist may be needed to discuss if alternate treatment is needed Infections may be accompanied by cutaneous manifestations (see Chapter 94 Infectious Disease Emergencies ) Although not unique to oncology patients, certain infections affecting the skin may be more common in this patient group Immunosuppressed patients are at increased risk for herpes simplex and herpes zoster Any skin lesions in a dermatomal distribution, with or without associated pain and whether or not the lesions are “classic,” should be considered herpes zoster until proven otherwise Immunocompromised patients with herpes zoster have an increased risk of disseminated disease and should be placed in respiratory isolation Evaluation should include chest radiograph and liver function tests If there is a vesicular lesion, it should be scraped and sent for both rapid testing (e.g., PCR) and culture for herpes simplex and varicella zoster Empiric therapy should be started with either acyclovir or one of its derivatives Admission for intravenous therapy is indicated in patients in whom there is evidence of dissemination, ophthalmologic involvement, or failure to respond to oral therapy Oral home therapy can be considered in consultation with the oncologist after considering extent of involvement, degree of underlying immunosuppression, likelihood of medication compliance at home, and ability to follow up COMPLICATIONS OF HEMATOPOIETIC STEM CELL TRANSPLANTATION Bone marrow transplantation is increasingly utilized in the treatment of various hematologic, oncologic, metabolic, or immunologic diseases In hematologic malignancies, allogeneic marrow transplantation may follow initial remission, induction, or disease relapse The allogeneic donor may be related, usually a sibling, or unrelated to the recipient In solid tumors and some lymphomas, patients may receive aggressive chemotherapy and radiation and then have their own stem cells infused as a “rescue” to help reconstitute their immune system following therapy (autologous transplant) Knowledge of the type of transplant a patient received ( Table 98.11 ) can help the clinician anticipate what complications might ensue In general, stem cell transplant recipients represent a fragile patient population at risk for many complications In approaching these patients, substantial immunosuppression should be presumed for at least months following the transplant For patients still receiving immunosuppressing medications, the period of immune dysfunction may be much longer Regardless of the WBC and neutrophil counts, immune function following a stem cell transplant can be profoundly impaired Graft-versus-host disease (GVHD) may develop in the setting of allogeneic stem cell transplants as newly engrafted immune cells of the donor react against tissue antigens of the recipient that are perceived to be foreign ( Table 98.11 ) Acute GVHD occurs in the first 100 days posttransplant, often when patient is still in hospital, and typically involves the skin, GI tract, or liver Chronic GVHD presents after 100 days and is accompanied by severe immunologic dysfunction The evaluation of patients with known or suspected GVHD following an allogeneic stem cell transplant should include assessment of potential dehydration or anemia due to colitis or dyspnea due to lung involvement Physical examination should assess the skin for rash, fibrosis, or jaundice, liver size and tenderness, and oxygen saturation, with a focus on screening for organ dysfunction serious enough to require intervention in the ED Clinicians should have a low threshold for admitting such patients for inpatient management due to overall fragility of this patient population Therapy for GVHD is primarily immunosuppressive using corticosteroids, cyclosporine, and other agents directed against T cells Specialists in hematopoietic stem cell transplant decide whether to pursue such agents and when Often a biopsy (skin, bowel, liver, etc.) is required to diagnose GVHD on histopathology The management of infectious complications for patients following stem cell transplant is not inherently different from the oncology population overall, but the relevant organisms may vary and the clinician’s level of suspicion may need to be higher ( Table 98.11 ) Infections in these patients result from the extreme immunosuppression achieved by myeloablation, cutaneous and mucosal barrier damage intrinsic to the transplant process, and the immunologic immaturity of the transplanted marrow Central lines exacerbate this risk Importantly, the types of infections patients tend to develop after hematopoietic stem cell transplant can vary based on how many days have elapsed since the transplant In the first month after the transplant, as patients are hospitalized and awaiting engraftment of their bone marrow, they are vulnerable to gram-positive and gramnegative bacteria, anaerobic bacteria, respiratory viruses, reactivation of herpes simplex virus, and fungal infection with candida and aspergillus After engraftment, from day 30 to 100 after the transplant, patients remain at risk for bacterial infections, particularly those related to their central lines Aspergillus and respiratory viruses continue to be a concern However, CMV, pneumocystis, and toxoplasma become more of a threat at this point More than 100 days after the transplant, patients are at risk for encapsulated bacteria, especially if they are simultaneously affected by GVHD or ongoing immunosuppression Aspergillus, pneumocystis, and toxoplasma continue to be a concern Viral infections with varicella zoster virus, CMV, EBV, and respiratory viruses are also a large threat for these patients When patients present to the ED with fever following a hematopoietic stem cell transplant, empiric coverage with antibiotics should be instituted quickly while cultures of the blood and urine are pending While gram-negative organisms have historically been of primary concern, gram-positive bacteria have more recently become more threatening, particularly with the emergence of MRSA in some regions Antibiotic regimens need to broadly cover gram-positive and gram-negative bacteria (e.g., piperacillin/tazobactam and gentamicin) as well as MRSA when relevant Rarely seen as a complication of stem cell transplant, thrombotic thrombocytopenic purpura (TTP) can present with the classic pentad of fever, neurologic symptoms, hemolytic anemia, thrombocytopenia, and renal compromise ( Table 98.11 ) The disorder seems to be associated with immunosuppression with cyclosporine or FK506 in the posttransplant period In some patients, TTP may evolve into a more chronic picture with renal dysfunction and a clinical picture more consistent with HUS An experimental, promising new treatment for leukemia involves chimeric antigen receptor modified T cells (CART) See Complications of CAR-T Cell Therapy section above In this specialized therapy, a patient’s T cells are harvested and engineered to express a receptor that allows them to seek out and destroy leukemic blasts These cells are then reinfused into the patient in an inpatient setting Importantly for emergency clinicians, steroids are contraindicated for any patients being treated with CART therapy since steroids are lymphotoxic and likely to be detrimental to this type of therapy CARE OF PATIENTS WITH ADVANCED CANCER Pediatric palliative care has seen major changes in recent decades and these developments clearly impact care for children with cancer Children with incurable cancer may still receive treatment that may be life prolonging and options for managing symptoms related to advanced disease have expanded Also noteworthy is the increased decision-making role for the patient and family members in the setting of advanced disease Options for patients to receive care outside of the hospital, either in hospice or at home, have greatly evolved  ... blasts These cells are then reinfused into the patient in an inpatient setting Importantly for emergency clinicians, steroids are contraindicated for any patients being treated with CART therapy... lymphotoxic and likely to be detrimental to this type of therapy CARE OF PATIENTS WITH ADVANCED CANCER Pediatric palliative care has seen major changes in recent decades and these developments clearly