RESUMEN
<p><b>Objective</b>To evaluate the analgesic effect of intrarectal local anesthesia (IRLA) versus that of periprostatic nerve block anesthesia (PPNB) in initial transrectal ultrasound-guided prostate biopsy (TRUS-PB) for patients with different prostate volumes (PV).</p><p><b>METHODS</b>A total of 253 patients undergoing initial TRUS-PB in our hospital from January 2014 to November 2017 were divided into three PV groups (<50 ml, 50－100 ml, and >100 ml), each again randomized into three subgroups (control, IRLA, and PPNB) with the random number table method. The pain during the procedure was assessed based on the Visual Analogue Scale (VAS) scores and the blind method was used by the biopsy operator, VAS valuator and data analyst.</p><p><b>RESULTS</b>Among the patients with PV <50 ml, the VAS scores in the blank control, IRLA, and PPNB subgroups were 4.39±0.87, 3.51±0.84 and 3.43±1.07, respectively, remarkably higher in the control than in the IRLA and PPNB groups (P<0.05), but with no statistically significant differences between the latter two (P>0.05). Among those with PV of 50－100 ml, the VAS scores in the three subgroups were 4.50±1.05, 4.38±1.13 and 3.38±1.44, respectively, markedly higher in the control and IRLA than in the PPNB group (P<0.05), but with no statistically significant differences between the former two groups (P>0.05). Among those with PV >100 ml, the VAS scores in the three subgroups were 5.19±1.05, 5.00±1.25 and 4.19±0.91, respectively, remarkably higher in the former two groups than in the latter (P<0.05), but with no statistically significant differences between the former two groups (P>0.05).</p><p><b>CONCLUSIONS</b>Either IRLA or PPNB can be recommended for initial TRUS-PB in patients with PV <50 ml, PPNB for those with PV of 50－100 ml, and PPNB with other painkillers for those with PV >100 ml.</p>