I dont know if this is helpful but its how I got through my labour. I was in an accident 10+ years ago, which left me with permanent spinal damage and in constant pain. In 2002 I learnt a technique called "The Gate Theory" through the municipal Pain Clinic. They taught me how to close the gates to pain without anything but thought. I couldn’t have survived the last 10 years without it and I also used this very technique during labour. It worked a charm. Even the midwives commented how high my pain tolerance was and how alert and clam I stayed throughout my labour.
Check it out there is a study book called: The Chronic Pain Control Workbook by Ellen Mohr Catalano. She explains the Gate Control Theory well.
K