Clinical review: Vasculitis on the intensive care unit – part 2: treatment and prognosis

The second part of this review addresses the treatment and prognosis of the vasculitides Wegener's granulomatosis, microscopic polyangiitis, Churg–Strauss syndrome and polyarteritis nodosa. Treatment regimens consist of an initial remission phase with aggressive immunosuppression, followed by a more prolonged maintenance phase using less toxic agents and doses. This review focuses on the initial treatment of fulminant vasculitis, the mainstay of which remains immunosuppression with steroids and cyclophosphamide. For Wegener's granulomatosis and microscopic polyangiitis plasma exchange can be considered for first-line therapy in patients with acute renal failure and/or pulmonary haemorrhage. Refractory disease is rare and is usually due to inadequate treatment. The vasculitides provide a particular challenge for the critical care team. Particular aspects of major organ support related to these conditions are discussed. Effective treatment has revolutionized the prognosis of these conditions. However, mortality is still approximately 50% for those requiring admission to intensive care unit. Furthermore, there is a high morbidity associated with both the diseases themselves and the treatment.     

Activity of nedocromil sodium in mast-cell-dependent reactions in the rat

Nedocromil sodium, a pyranoquinoline dicarboxylic acid derivative which differs structurally and physiochemically from sodium cromoglycate, was nonetheless shown to be effective in classical models of anti-allergic activity in the rat. These models, based on immediate hypersensitivity reactions in the passively sensitized rat, involve release of mediators from mast cells following cross-linking of membrane-bound IgE antibodies by specific antigen. In this system, nedocromil sodium exhibited a similar profile of activity to that of sodium cromoglycate. Whilst not predictive for therapeutic activity, rat models of immediate hypersensitivity are believed to reflect one component of obstructive airways disease. The results suggest that nedocromil sodium is worthy of clinical evaluation in this indication.