Bilateral pudendal nerves block for postoperative analgesia with 0.25% S75:R25 bupivacaine. Pilot study on outpatient hemorrhoidectomy.

BACKGROUND AND OBJECTIVES: Hemorrhoidectomy may be performed under several anesthetic techniques and in outpatient regimen. Postoperative pain is severe and may delay discharge. This study aimed at evaluating bilateral pundendal nerves block for post- hemorrhoidectomy analgesia.
METHODS: Bilateral pundendal nerves block with 0.25% S75:R25 bupivacaine was performed with nerve stimulator in 35 patients submitted to hemorrhoidectomy under spinal anesthesia. Evaluated parameters were pain severity, duration of analgesia, demand analgesia and possible technique-related complications. Data were evaluated 6, 12, 18, 24 and 30 hours after surgery completion.
RESULTS: Successful pudendal nerves stimulation was achieved in all patients. There has been no severe pain in all evaluated moments. At 12 hours after blockade, all patients had perineal anesthesia; at 18 hours, 17 patients and at 24 hours, 10 patients still presented perineal anesthesia. Postoperative analgesia was optimal for 18 patients; satisfactory, for 5 patients; and unsatisfactory, for 7 patients. Mean analgesic duration was 23.77 hours. There were no changes in blood pressure, heart rate, no nausea and vomiting were observed. All patients had spontaneous micturition. No local anesthetic-related local or systemic complications were observed. Technique was considered excellent by 27 patients and only 3 male patients considered it satisfactory due to penile anesthesia.
CONCLUSIONS: Bilateral pudendal nerves block oriented by nerve stimulator provides excellent analgesia with low need for opioids, without local or systemic complications and without urinary retention. Controlled studies might be able to show whether this should be the first analgesic option for hemorrhoidectomies. Perineal anesthesia lasting 20.21 hours shall induce further studies with stimulator-oriented pudendal block.