RESUMEN
To evaluate the role of needle diameter in causing postdural puncture headache [PDPH] in patients undergoing elective caesarian section. Comparative cross-sectional study. This study was conducted in Department of Anaesthesia and Intensive care PNS Shifa Karachi over duration of six months. It was a cross sectional study of 100 patients, which were divided into two separate groups. Group I and Group II were given spinal anaesthesia with 25 gauge and 27 gauge Quincke needles respectively. In both the groups the patients were randomly selected and were blind to size of the spinal needle used. The data was analyzed using Chi-square test. A P value of <0.05 was considered statistically significant. Two patients in 25-G group and one in 27-G group required additional general anaesthesia because of inadequate spinal anaesthesia. Thus, a total of three patients were excluded from the study. Five out of forty-eight patients in group 1 and one out of forty-nine patients in Group II suffered from post spinal headache. The proportion of patients with post spinal headache with 25 G needle is significantly more than those with 27 G