RESUMEN
The incidence of postspinal headache is one of the well known complications of spinal anesthesia. Several factors such as needle size, bevel direction, multiple dural puncture and previous history of postspinal headache were thought to influence the incidence of postspinal headache. This studies were done to see the effect of needle size (22 and 25 gauge needle) and needle bevel direction (parallel, vertical, oblique insertion to the longitudinal dural fiber) on the incidence, duration, severity and location of spinal headache in the 548 patients underwent spinal anesthesia. The following results wre observed: 1) Neither needle size nor needle bevel direction had effect on the incidence of severity, duration and location of postspinal headache. 2) The ineidence of headache was 8.8% (48 cases), 3) The onset of headache was 1~2 day (67%) and duration of headache was 4~5 day (85%) in postanesthetic day. 4) The severity of headache was mild and moderate in 77% cases. 5) In the half cases, headache was relieved by means of bed rest alone.