Evaluation and treatment of vasculitis in the critically ill patient

The inflammatory vasculitides are a group of multisystem diseases that can result in rapid clinical deterioration and admission to an intensive care unit (ICU). Vasculitis is usually idiopathic and often difficult to diagnosis quickly making the approach to these patients especially challenging in an ICU. Critical illness may be the initial presentation of an inflammatory vasculitis, it may be the result of progressive primary or recurrent disease or it may be due to complications of treatment, such as sepsis. This article focuses on critical care aspects of patients with vasculitis with a focus on the approach to diagnosis and treatment in the ICU. A particular emphasis is placed on the renal manifestations of the diseases. The most difficult aspect of diagnosing a case of vasculitis is often simply considering it in patients with severe multisystem disease. It must be emphasized that vasculitides are rare diseases and often mimic other diseases, such as infections and malignancies. Furthermore, because treatment for severe vasculitis almost always involves high-dose glucocorticoids and immunosuppressive agents, infections must be carefully ruled out even in patients who clearly have vasculitis. Patients who already carry an established diagnosis of vasculitis can present to an ICU with an exacerbation of their underlying inflammatory process, an infectious complication of therapy, or both problems. In can often be difficult to determine whether patients with a history of vasculitis have active disease. Currently, there are no fully reliable measures of disease activity for vasculitis and it is often necessary to embark upon an extensive evaluation in such patients to determine disease activity.