N MANY hospitals, spinal (subarachnoid) I block is not administered for surgical or obstetric procedures for two principal reasons: (1) the complications, particularly headache and paralysis, are well known to the public; and (2) a lawsuit may result if a major complication occurs. Since headache from epidural block does not occur unless the dura is inadvertently punctured; since, as yet, the complications of epidural block and the term "epidural" are not known to the public; and, since relaxation following epidural block is comparable to that after spinal block, many anesthesiologists are now employing epidural anesthesia.The following questions, therefore, arise: Is epidural block as safe as spinal block? Which of the two technics is the more dependable? Is epidural block the answer to patient objections to spinal block?In our institution, both spinal and epi-dural blocks are administered to surgical and obstetric patients. The anesthesiologist sees the patient before surgery and tells him that he is to have either a spinal or epidural block, and the anesthesiologist sees the patient postoperatively. Because many of these patients return to the clinic for all medical needs, a comprehensive accumulation of data has been possible. METHOD OF STUDYData from a previous report on 11,574 cases of spinal block, from 1948 through 1964,l were combined with those from the present study by (1) preparing a tally sheet; (2) establishing a method of coding for the tally sheet; (3) transferring data from the anesthetic records to the tally sheets; (4) transferring tally sheet data to a standard 80-column punch-card; (5) verifying accuracy of transfer by a second operator; (6) reading the verified cards into a computer; and (7) storing the data on magnetic discs ready for processing.