Telling patients to count backwards from 100 reduces pain during surgery, according to a study.

A soothing hand on the brow from a nurse or self-hypnosis techniques involving conjuring up images of floating reduced the quantity of pain-killing drugs required by patients.

Researchers from the Beth Deaconess Medical Centre in Boston, Massachusetts, compared the use of the techniques in 241 patients undergoing radiological investigation of problems with their circulation or kidneys.

The investigations involved key-hole surgery to insert a catheter into a vein and thread it to the part of the body - the heart or kidney - to be examined. This is normally carried out while the patient is awake but drugs are given to reduce pain and anxiety. Elvira Lang and colleagues found that patients given standard treatment experienced increasing pain during the procedure while those given intensive nursing care or self-hypnotic relaxation did not.

The group having the standard treatment required more drugs but the procedure still took longer to complete because of their greater pain. They suffered more sideeffects from the drugs, such as vomiting and over-sedation, and occupied the operating theatre for 17 minutes longer.

Dr Lang's team found that there were fewer complications with the circulation in the group that had self-hypnotic relaxation, suggesting that it is safer than standard treatment with pain-killing drugs.