Many will attest to early-day mishaps in terms of too early (or too late!) holding on extraction of needles leading to blood spillage and frustration at the close of a dialysis session. As with the entire HHD paradigm patience is key and here involves slow, watchful tugging on the luer cap as the needle is coaxed smoothly from its erstwhile lodging. A sterile swab, rolled into a tight little sausage will allow one to move it into position close by without obscuring the exact point the tip of the needle is about to exit from. This means there'll be no need to hold the swab against the skin during extraction. A look at the fearfully sharp edges of the needle bevel (see image) should convince that any pressure exerted on those edges against flesh, skin or vessel will be prone to lacerate. Sure there may be some spillage if one waits for the needle tip to clear the orifice, - perhaps a 1/4 teaspoon or less as one gains timing skill with practice.