My DS who is 2 has to have blood taken every couple of weeks to monitor drug levels and liver function after a liver transplant last year. He had a permanent line in for quite a while but it was taken out just before Christmas and since then they have had to take blood from his little arms. I practiced before hand with a plastic syringe so he would be familiar with what they were going to do . We also pretended to take blood from his toy lion and let him pretend to take blood from me and DH. It really seemed to have helped as he sits on my knee, completely calm (I make sure I'm calm too), they have a play specialist who helps with distraction, using bubbles and toys. Sometimes he doesn't even notice the needle going in and coming out. Sometimes he gives one little cry as it goes in, then is very easily distracted and forgets all about it.
I know he's much younger and I have probably been lucky in that I could almost brainwash him that it doesn't hurt. They don't use any cream or spray on him either. Maybe you could try practicing before hand and also try some sort of reward system. Hope it goes better next time.