Phlebotomist and lab tech here.  The worst last words I heard from a patient were an elderly man begging for a drink of water.  He was scheduled for a procedure I believe, and was to have nothing by mouth.  His nurse reminded him he couldn't have any, but I don't think he was capable of hearing it.  I was in the room to check his blood sugar.  I finished my paperwork and he gently coded.  More than 15 years later it still upsets me that in someone's time of a most basic need, I did nothing.  I know I could not have given him a drink, but I could have put off my responsibilities for a minute and helped him by swabbing his mouth with a little mouth sponge soaked in cold water.  I don't know if there is anything on the other side, but I hope for him a loved one met him there with a cold drink of water.