Sentence:  An artificial kidney these days still means a refrigerator-sized dialysis machine. Such devices mimic...real kidneysnb.... But they are nothing like as efficient, and can <WSD>cause</WSD> bleeding, clotting and infection—not to mention inconvenience for patients, who typically need to be hooked up to one three times a week for hours at a time. 
Meaning of the word marked with <WSD> tags:  To set off an event or action.