Multiple Myeloma

Multiple myeloma is a malignant neoplasm of terminally differentiated plasma cells that clonally proliferate in the bone marrow, producing a monoclonal immunoglobulin (M protein) and causing multisystem disease summarized by the CRAB criteria: Calcium elevation (osteoclast-activating factors released by myeloma cells cause osteolytic bone destruction and calcium release), Renal insufficiency (monoclonal light chains precipitate in renal tubules causing cast nephropathy, hypercalcemia, and amyloid deposition), Anemia (marrow replacement and cytokine-mediated suppression of erythropoiesis), and Bone disease (punched-out lytic lesions, pathological fractures, vertebral compression fractures with severe bone pain). The monoclonal immunoglobulin can cause hyperviscosity syndrome (visual changes, neurological symptoms, bleeding) and the suppression of normal immunoglobulin production causes immunoparesis with increased infection susceptibility. The nurse monitors serum calcium, creatinine, CBC, and M protein levels, manages bone pain with multimodal analgesia, implements fall prevention and safe mobilization (pathological fracture risk), administers chemotherapy (bortezomib, lenalidomide, dexamethasone) as prescribed, monitors for tumor lysis syndrome, administers IV bisphosphonates for bone protection, monitors for signs of spinal cord compression (emergency), and manages central venous access for treatment.