S267 INTRODUCTION: The pencil point 25G Pencan spinal needle and 22/24G Safetap tapered atraumatic point spinal needle have recently become available. This ongoing, prospective study was designed to compare the insertion characteristics and the incidence of complications of 25G Pencan[registered sign], 22/24G Safetap[trade mark sign] and 25G Whitacre spinal needles. METHODS: Following IRB approval, informed consent was obtained from 112 ASA 1-2 patients undergoing postpartum tubal ligation. They were randomly assigned to receive spinal anesthesia with either a 25G Whitacre (Becton and Dickinson), 25G Pencan (B. Braun Medical Inc.) or 22/24G Saftap (S22/24) (Kendall Healthcare) needle. A standard midline approach was used with patients in a sitting position. After a CSF aspiration test, Lidocaine 5%, 1.3-1.5ml was injected. The following data were collected: positive dural click, time for three CSF drops after the appearance of CSF at the end of the hub of the needle, and successful spinal block after appearance of CSF at the hub. Any missed segments or peritoneal discomfort during the surgery was treated with 5-10 mL, 1% lidocaine infiltration, and in the event of failed spinal block after CSF appearance, general anesthesia was induced. The patients were followed in the postoperative period by an observer blinded to the study groups for headache, backache, and any other complications. ANOVA with the Student-Newman-Keuls multiple comparison test and Chi-square test were used for statistical analysis as appropriate. A p-value <0.05 was considered significant. RESULTS: Patients in all three groups were similar with respect to demographic data. Positive dural click with the needle was greater in the Pencan and Whitacre groups than in the Safetap group. The rate of the CSF flow was greatest through the Safetap needle than through the Pencan and Whitacre needles. There were no differences observed between groups in terms of need for an infiltration, failed spinal, and PDPH (postural headache) (Table 1). No patient required blood patch.Table 1: Summary of results. n (%);DISCUSSION: In this study we were able to achieve a high rate of successful spinal anesthesia with all three needles. The higher CSF flow rate with the Safetap and Pencan needles may be attributed to the design of the tip and the size of the needles. A higher incidence of distinct dural click with the Whitacre and Pencan needles seems to be related to their rounded edge pencil point tip. Technically rapid CSF flow through the needle and positive dural click are desirable features of a spinal needle. Based on the finding herein and our clinical experience, we feel that the 25G Pencan needle may be the optimal size and type needle. However, further large-scale study is required to better define incidence of perioperative complications and failed spinal with the Pencan and Saftap needles.