"no feeling in hand and arm"

On Thursday I attended for a colonoscopy, I was very nervous as my partner had died the previous year from bowel cancer, I asked to be sedated and was given an injection into the back of my hand through a canular, all the way through I was in terrible pain and kept insisting the sedative had not worked, I was told it had, they didn't believe me, now today Saturday I woke up and from the injection site all the way to my elbow it is numb, and tingling, two weeks previous to this procedure I had attended for a gastroscopy and was sedated on the back off the hand, I didn't know anything until I woke up and the procedure had been completed. a very different outcome to the suffering I was caused in colonoscopy! I have been trying to find out what is happening to my hand an arm, I have had no luck and do not know where to find out. I have my own theory, I think the nurse put in the canular but it went into the vein and then out of it, so the sedative went into my hand and not the vein