Abstract

The effect of needle bevel direction on the frequency of postspinal headache (PSH) was investigated in 482 patients undergoing spinal anesthesia. Ten of 62 patients in whom the spinal needle bevel was inserted perpendicular to the longitudinal dural fibers developed PSH. Among 420 patients who underwent parallel insertion only one developed PSH. A system of criteria for registering PSH is proposed. The way of puncturing the dura was found to be a much more important factor influencing the occurrence of PSH than the needle size (22- versus 25-gauge needles), age, sex, or duration of postoperative recumbency.