Critical illness as a result of anti-neoplastic therapy

Although cancer is responsible for more deaths in children over 1 year of age than any other disease, outcomes are improving as a result of many factors including better supportive care and increasingly aggressive anti-neoplastic regimens. As a result, the pediatric intensivist will likely encounter many complex clinical challenges related to the therapy for childhood cancer. Chemotherapy can, in the course of reducing tumor burden, also bring about life-threatening changes in organ function, metabolism and electrolyte levels. The destruction of tumor cells results in the release of intra-cellular contents in tumor lysis syndrome, and this may lead to a range of problems including cardiac arrhythmias, tetany and renal failure. In addition, the chemotherapy may produce life-threatening toxicity to otherwise healthy tissues. An understanding of these toxicities enables the intensive care physician to anticipate problems and intervene in a timely manner. Radiation therapy can also lead to a wide variety of organ dysfunction, most notably, lung injury. Radiation pneumonitis presents a true diagnostic challenge requiring a clear understanding of both the use and timing of anti-neoplastic therapy in conjunction with an appreciation for the clinical and radiographic findings suggestive of this disorder. Additionally, the impact of anti-neoplastic therapy on the immune system has been well established. Neutropenic enterocolitis (typhlitis) is an acute, potentially life-threatening, necrotizing inflammation of the cecum and colon reported to occur in children treated for leukemia as well as other malignancies. Furthermore, the myelosuppression associated with many forms of anti-cancer therapy predisposes the child with cancer to bacteremia and sepsis. Encouragingly, with timely critical care interventions, the outcomes from severe sepsis in non-transplant oncology patients now approximate those of the general pediatric population. In sum, therapy for cancer in children can profoundly impact physiology and the pediatric intensivist must have a sound working knowledge of these effects.