Aquapheresis: An Alternative Method of Controlled Fluid Removal in the Setting of Hypervolemia and Refractory Gout in Sickle Nephropathy

Introduction: Gout flares and vaso-occlusive attacks complicate acute diuresis in patients with sickle cell nephropathy and volume overload (VO). Loop diuretics are considered first line therapy in the management of VO. We present a case in which aquapheresis (AQ) was used as an alternative and more effective method of fluid removal in a patient with sickle cell nephropathy and secondary pulmonary hypertension complicated by refractory gout and sickle pains upon IV diuresis. Case Description: A 48-year-old patient with sickle cell nephropathy, gout, pulmonary hypertension presented with shortness of breath and bone pain. The physical exam was significant for hypoxia, lower extremity edema and bone tenderness. Chest x-ray showed pulmonary edema. The patient was diagnosed with sickle cell crisis and hypoxic respiratory failure secondary to VO. He was initiated on IV furosemide and analgesics. With diuresis, he developed severe right wrist pain consistent with an acute gout attack despite appropriate treatment. His vaso-occlusive attacks worsened. Upon decreasing the IV diuretic dose, he developed hypervolemic respiratory failure. His kidney function remained stable. Aquapheresis (AQ) consists of the extracorporeal extraction of plasma fluid from the vascular space across a semipermeable membrane. In AQ, fluid removal is controlled by specifying an hourly ultrafiltration rate. This modality offers controlled fluid removal. Upon initiating AQ and stopping IV diuresis, the patient’s weight dropped by 10 Kg over several days. He had significant improvement in his respiratory status and remission in his gout flare with a drop in his serum uric acid levels (10.6 to 4.9 mg/dL). His vaso-occlusive pains improved. Discussion: In summary, AQ was successful in treating hypervolemia in a patient with sickle cell nephropathy and a stable renal function. Uncontrolled and excessive fluid removal using IV diuresis can exacerbate vaso-occlusive disease and precipitate gout flares in patients with sickle cell nephropathy. Controlled fluid removal using AQ reversed the acute rise in uric acid mitigating gout flares and alleviating vaso-occlusive disease with improved pain control. AQ promises to be a superior method for controlled fluid removal in hypervolemia in patients with sickle cell nephropathy complicated by VO and hypoxia.