SMH
aspiration is pointless.  it won't tell you if you hit a vein, and just cause you don't get blood doesn't mean you didn't clip a vein 
i haven't aspirated in years and don't plan to.  it does more harm than good.  just another reason to move the needle
i can't believe in 2018 that we still have this bro science myth of 'you must aspirate' still on these forums