Clinical meaning
Oncological emergencies are acute, life-threatening complications that arise either from the cancer itself or from its treatment. These emergencies require rapid recognition and immediate intervention to prevent irreversible organ damage or death. The four most critical oncological emergencies that practical nurses must recognize are tumor lysis syndrome (TLS), superior vena cava syndrome (SVCS), malignant spinal cord compression (MSCC), and hypercalcemia of malignancy. Tumor lysis syndrome occurs when large numbers of cancer cells are destroyed rapidly, most commonly within 12 to 72 hours after initiating chemotherapy for highly proliferative cancers such as acute leukemia or high-grade lymphomas. When tumor cells lyse, they release their intracellular contents into the bloodstream: potassium (causing hyperkalemia), phosphorus (causing hyperphosphatemia), uric acid (from nucleic acid breakdown), and nucleic acids. Hyperphosphatemia binds with calcium, causing secondary hypocalcemia. Uric acid crystallizes in the renal tubules, leading to acute kidney injury. The combination of hyperkalemia and hypocalcemia creates a high risk for fatal cardiac dysrhythmias. Superior vena cava syndrome results from compression or obstruction of the superior vena cava (SVC) by a mediastinal tumor, most commonly lung cancer or...