Table 2. Effect of Epidural Needle Design on CSF Leak (90° Punctures, Bevel Parallel), Cadaver n = 10

Part 1 results are presented in the form of a P  value matrix. Mean ± SD cerebrospinal fluid (CSF) leak rates are found on the diagonal for each needle in ml/15-min interval. The table may be read in the following way: Mean ± SD leak for the 17-g Hustead = 516 ± 319 (17-g Hustead [row]vs.  17-g Hustead [column]). Mean ± SD leak rate for the 17-g Tuohy (row) vs.  17-g Tuohy (column) = 405 ± 209. P  value for differences in leak for the 17-g Hustead (row) vs.  17-g Tuohy (column) = 0.3668. P  value required to reach statistical significance, corrected for multiple testing = 0.003.

* Statistically significant P  values.