such as a cellulose membrane of the artificial kidney or a peritoneal natural membrane of the peritoneal cavity dialysis solutions remain in the patient 39 s peritoneal cavity in intermittent peritoneal dialysis for a time sufficient for blood impurities to be removed by diffusion across the peritoneal membrane into the dialysis solution the impurity containing dialysis solution then is drained from the peritoneal cavity by means of a catheter and tubing and a fresh supply of dialysis solution is infused again it is important that the catheter be adapted so as to efficiently and continuously infuse and remove fluids to and from the patient with a minimum of trauma thus in use in kidney dialysis the dual lumen catheter of the invention 10 is inserted at end 11 into the subclavian artery femoral vein or jugular vein of the patient such that ports 13 15 are contained within the vein and thus are in fluid communication with the vein or artery luer lock caps 29 30 are removed from adapters 27 28 respectively and connected to the dialysis machine via tubing extensions not shown when dialysis is commenced clamps 25 26 are released to allow flow of fluid through tubing extensions 23 24 the dual lumen catheter of the invention is particularly useful for kidney dialysis in that it is flexible along its length by virtue of the curved septum 8 thus the catheter tube will not kink or.