Spinal anaesthesia with plain 0.5% bupivacaine at 19 degrees C and 37 degrees C

Forty-five men aged 50-80 yr undergoing urological surgery under spinal anaesthesia were allocated randomly to three groups. All patients received 0.5% plain bupivacaine 3 ml injected at the L2-3 interspace. The temperature of the solution in group 1 was 19 degrees C, in groups 2 and 3 37 degrees C. In groups 1 and 2 the injection was performed with the patient sitting; in group 3 the patient was in a lateral horizontal position. Spread of block, intensity of motor block and cardiovascular stability were measured. Warming the solution from 19 degrees C to 37 degrees C before spinal injection with the patient in the sitting position did not significantly affect these variables. However, the extent of analgesia was reduced significantly when the 37 degrees C solution was injected with the patient in the lateral horizontal compared with the sitting position.