The effects of hypnosis on bleeding

Following ethics approval and written informed participant consent, study participants will be asked to sit comfortably in a vacant clinical room such as DOSA. Here subjects will have a standardised hypnotic induction by an experienced hypnotist (AMC) using an eye fixation technique and progressive muscle relaxation for deepening the trance state. After suggestions for the development of arm anaesthesia using anaesthetic glove imagery, small areas of skin over the anatomical snuff box of each hand will be cleaned by the hypnotherapist / anaesthetist with antiseptic wipes. After obtaining permission from the volunteer while in hypnosis (either with a finger signal or nod of the head) a 23 gauge needle will be inserted through a skin fold overlying the anatomical snuff box in each hand. Following randomisation of which arm will stay in hypnosis (the participant’s left or right) suggestions will be given for the allocated arm to stay in hypnosis when the needle is removed and that bleeding will be controlled so that the skin stays dry. Similarly in the contralateral arm allocated to bleed normally when the needle is removed, it will be suggested that when the needle is removed the arm will come out of hypnosis and the blood vessels return to their normal caliber so that bleeding occurs normally. A second researcher will then be asked to enter the room to measure our key outcomes. Both needles will then be removed simultaneously and bleeding from each puncture site measured by this researcher using filter blotting paper to absorb any blood and a stopwatch to time when bleeding starts and ceases in each hand following needle removal. The Randomisation will be obtained by a computer generated random number sequence and allocation concealment assured by using consecutively numbered opaque envelopes containing the randomisation sequence. The envelopes will be opened after needle insertions but before the outcome assessor enters the room. Following the hypnosis intervention a blinded observer will measure bleeding using absorbant standardised blotting paper on removal of the needles and the outcome assessor will measure the spread of blood absorbed by the paper in mms and he/she will be asked which arm they believe to be hypnotized. Dependent on equipment availability we also plan to use thermo-imaging of the puncture site as a measure of temperature change and local blood flow as a secondary outcome. Videotaping of the whole process is also planned. We plan to recruit 20 subjects in the first instance. Following completion of all measurements, participants will have their hypnosis terminated in a standardised fashion and all prior hypnotic suggestions removed as subjects return to normal conscious awareness. Data collection will be via a data-sheet for each patient. Study data will then be transcribed on an excel spreadsheet for further analyses. Descriptive statistics will be reported, Chi squared between arms for dichotomous outcomes and students t test for continuous data such as blood blotting paper measurements will be used as appropriate. Differences in the measurements of bleeding outcomes between the two allocated hypnosis and non hypnosis hands will be analysed and a P values < 0.05 will be considered significant.