dr. zivot, from a medical perspective, what kind of problem does this present? >> from the medical perspective, nide to be clear that the lethal injection is not -- i need to be clear that medical injection is not a medical act. if you're asking me what is the role of the drugs and how does it affect my practice, pentabarbital has a particular use which is related to the treatment of seizures. other medications used in lethal injections are medications that i require to give patients and if i have to be competing, so to speak, with the department of corrections over who gets certain kinds of medications, that creates an unusual kind of circumstance where medication that really is intended to heal is now in fact used to kill. >> woodruff: part of the questions being raised, doctor, have to do with whether these are effective for what they are designed to do even if they are designed to kill and whether in fact some of these inmates are suffering more than they ought to. is there any way to measu