A fluid removal apparatus comprising a blood removal catheter for insertion into a peripheral vein or artery and having a size 16 standard gage needle or less; a filter having a blood inlet port coupled to the blood removal catheter, a blood outlet port, an excess fluid removal port, and a blood flow passage with porous membrane which passes fluids to the fluid removal port and retains solutes of 60,000 Daltons or greater, and a blood return catheter for inserting into a peripheral vein or artery and having a size of 16 standard gage needle or less.