Audiometric changes following spinal anesthesia

A prospective study on audiometric changes following spinal anaesthesia with different gauge spinal needles was carried out in 125 patients; the patients were randomly divided into five groups according to gauge of needles used i.e., 20, 22, 23, 24 and 25 with twenty five -patients in each group. Twelve percent and 8% decrease in audiometric values were recorded on first postoperative day at 250-500 Hz frequencies with 20 and 22 gauge needles respectively and these changes were highly significant [P < 0.001]; these audiometric alterations returned to within normal limits by the 5th postoperative day. Eight percent decrease in audiometric values were observed on first postoperative day at 250-500 Hz frequencies with 23 gauge needle which was also statistically significant [P<0.05]; these changes returned to near normal limits by the 5th postoperative day. There was no significant decrease in the audiometric values following spinal anaesthesia with 24 and 25 gauge needles