Comparison of 26- and 27-G needles for spinal anesthesia for ambulatory surgery patients

Seven hundred thirty ambulatory surgery patients, randomly assigned to receive spinal anesthesia with a 26- or 27-G needle, were studied for the incidence of post-dural puncture headache (PDPH), postoperative back pain, and patient acceptance. The incidence of PDPH following the use of 26- and 27-G needles was 9.6% and 1.5%, respectively (P less than 0.05). The incidence of PDPH was 5.7% among men and 13.4% among women following the use of 26-G needles (P less than 0.05), whereas no difference between men and women was noted after the use of 27-G needles. Of the patients who were 40 yr of age or younger, the overall incidence of PDPH was 11.9%, with a 7.5% incidence among men and a 16.4% among women following the use of 26-G needles (P less than 0.05) and a 1.8% incidence of PDPH following the use of 27-G needles, with no statistical difference between genders. Postoperative back pain was experienced in 18.3% of the patients in the 26-G group and 20.2% in the 27-G group (difference not significant). Favorable acceptance of spinal anesthesia was reported in 89.4% of patients in the 26-G group and 98.2% in the 27-G group (P less than 0.01). Results from this study demonstrate that, in patients who received spinal anesthesia for ambulatory surgery, the use of 27-G needles resulted in a significantly lower incidence of PDPH and greater patient acceptance compared with the use of 26-G needles. The incidence of postoperative back pain was not significantly different between the two groups.