Multiple myeloma is a neoplastic proliferation of a plasma cell clone that produces a monoclonal immunoglobulin. It is one of the most common haematological malignancies and the incidence increases with age, with a median age at diagnosis of 65–70 years. The diagnosis of multiple myeloma requires the presence of ≥10% plasma cells in the bone marrow and an M-protein in serum and/or urine. Cytogenetic status, serum β2-microglobulin and response to therapy are the key prognostic factors. Treatment is necessary for the patient diagnosed with symptomatic multiple myeloma, with organ damage. Patients older than 65 years are ineligible for autologous transplantation. The introduction of novel agents, such as thalidomide, bortezomib and lenalidomide, have changed the management of myeloma and extended overall survival. However, in older patients the results are not as satisfactory and treatment strategies have to be individualized to improve tolerability and optimize efficacy.

As the proportion of elderly people in the general population increases, so does the number admitted to critical care. In caring for an older patient, the intensivist has to balance the complexities of an acute illness, pre-existing co-morbidities and patient preference for life-sustaining treatment with the chances of survival, quality of life after critical illness and rationing of expensive, limited resources. This remains one of the most challenging areas of critical care practice.