Extradural analgesia revisited. A statistical study.

The results of 334 lumbar extradural analgesics, administered in a standard manner, allowed reassessment of some factors influencing the spread of local anaesthetic solution in the extradural space. There was no evidence of increased spread in patients with degenerative vascular disease when compared with a control group free from such disease. The patient's height and age had a small effect on spread. The results contradict the earlier assumption of a direct relationship between the volume of anaesthetic solution injected and the number of segments blocked.