consistent with necrotic bowel Serial abdominal x-rays should be performed to look for intramural air (pneumatosis), which is a hallmark of this diagnosis, or free air, which is an indication for surgery A CT scan of the abdomen can be useful for better delineation of the degree of bowel wall injury If CT scan is unavailable, ultrasound can show bowel wall thickening Early surgical consultation is appropriate Surgery itself is reserved for uncontrollable coagulopathy or acidosis as a consequence of bowel necrosis or evidence of perforation Treatment of confirmed or suspected C difficile colitis should include empiric vancomycin (oral) or metronidazole (parenteral or oral) Imaging is rarely useful, except in the most severe cases As soon as characteristic vesicles on an erythematous base are seen, empiric coverage for varicella should begin with acyclovir 10 mg/kg IV every hours in conjunction with appropriate hydration The patient should be assessed for pneumonitis with a careful respiratory examination, oxygen saturation, and a chest radiograph Liver enzymes should be measured for possible hepatic involvement All pediatric patients with fever and neutropenia less than 500 to 1,000 per μL should be admitted to the hospital unless there is an institutional management guideline that includes a specific follow-up plan for outpatient management of lowrisk fever and neutropenia See the Children’s Hospital of Philadelphia Clinical Pathway for Oncology Patient Presenting with Fever In the case of sepsis or septic shock, acute management as described in the Children’s Hospital of Philadelphia Severe Sepsis Clinical Pathway and Chapter 94 Infectious Diseases Emergencies should be followed for oncology patients, with the empiric antibiotic coverage described above for neutropenia Stress-dose steroids should be considered in patients who have received prolonged steroids recently either as part of cancer treatment or management of nausea and vomiting COMPLICATIONS OF CAR-T CELL THERAPY Goals of Treatment Some patients with refractory or relapsed ALL or B-cell lymphoma may have undergone treatment with chimeric antigen receptor modified T cells (CAR-T cell therapy) This approach genetically modifies autologous T cells to express a receptor which targets antigens on the surface of lymphoblasts Though not currently available in all centers, the early success of this therapy is likely to contribute to more widespread use Patients who have received CAR-T cell therapy are at risk for serious and potentially fatal complications, including TLS, cytokine release syndrome, and neurotoxicity