An unusual case of persisting hypoxia in a patient with a thrombolysed pulmonary embolism.

Exertional breathlessness and hypoxia are common presenting complaints in acute medicine. We describe a case where the patient continued to have persistent hypoxia even after the primary cause (pulmonary embolism) was diagnosed and treated. The hypoxia persisted as an enigma, its cause remaining elusive till diagnosed. Standard first-line investigations would not have reached the underlying diagnosis in this case and, as such, it demonstrates the keen clinical sense and complex investigative strategy required to solve the puzzle.

Induction treatment of ANCA-associated vasculitis with a single dose of rituximab.

OBJECTIVES: Rituximab is effective in inducing remission in ANCA-associated vasculitis (AAV), with randomized evidence to support its use as four infusions of 375 mg/m(2) (the conventional lymphoma dosing schedule). As B cell depletion (BCD) appears to occur very rapidly after the first dose, we questioned the need for repeat dosing and adopted a standard single-dose protocol of 375 mg/m(2) to treat active AAV. METHODS: All consecutive cases with newly diagnosed or relapsing AAV for whom conventional immunosuppression was contraindicated or ineffective were enrolled. All were rituximab naive. Circulating CD19(+) B cells and clinical and serological markers of disease activity were recorded at regular intervals. Complete remission (CR) was defined as the absence of clinical features of AAV with a prednisolone dose <10 mg/day. RESULTS: Nineteen patients were included, 17 (89%) with generalized disease and 2 (11%) with severe disease (creatinine level >500 µM). Eight (42%) were on additional immunosuppression at the time of rituximab treatment. Satisfactory BCD (<0.005 cells/µl) was achieved in 89% of patients after a median of 13 days. Three-month BCD probability was 89%. Median time to CR following a single dose of rituximab was 38 days and the 3-month probability of CR was 80%. Median time to B cell repopulation was 9.2 months and to disease relapse/redose was 27 months. Use of this single-dose protocol saved an estimated £4533/patient (US$7103; €5276) compared with a 4 × 375 mg/m(2) dosing schedule. CONCLUSION: Our single-centre experience suggests that a single dose of rituximab of 375 mg/m(2) is a reasonable and more cost-effective therapy for inducing remission in patients with AAV.