If Justice Souter really wants to know what cruel and inhumane punishment is, go to the hospital and have a doctor insert an IV. The Justice's objection that a doctor ought to be the one putting in the needle (and the lame response from the Kentucky counsel that such work is "scut work") shows that neither of them are very familiar with hospitals, needles, and blood work.
Give me a trained tech who does 200 sticks a day (or even the person who does 90 a day in the prison according to counsel in the case), and I'll feel no pain. Most doctors haven't done a needle stick in years....and even though student doctors are bad (the price you pay for going to a first-class teaching hospital is having a let a few interns stick you) a long-time doctor is usually worse because she or he has probably not wielded a syringe since the end of residency.