Needle size used PDPH % of patients with PDPH Yes No 18G 7 4 63.60% 20G 24 25 49% 22G 9 20 31% 24G 4 11 26.60% <24G (25,26&27) 1 11 8.30%

Table 3: percentage of PDPH developed when specific needle sizes were used among the study participants of GUH who developed PDPH, February 25-April 10, 2013.