Anaesthetic potency in epidural analgesia.

IN an extensive literature on epidural analgesia there appears to be some difference of opinion as to the intensity of nerve block produced by different drugs, perhaps partly attributable to the fact that many patients are given light narcosis in addition to nerve block, nowadays, which may conceal differences of drug action. In quoting a few of the many authorities, the following drugs are listed according to the original author's assessment of the relative strengths as regards sensory and motor block, independent of duration, although the actual concentrations used by the different observers varied.