Comparison Of Ultrasound-guided Sacral Nerve Block And Pudendal Nerve Block For Postoperative Analgesia After Anorectal Surgery

Purpose:To investigate the effect of ultrasound-guided sacral nerve block and pudendal nerve block for postoperative analgesia after anorectal surgery.Methods:One hundred and twenty patients who underwent hemorrhoidectomy were selected,all of them were ASA grade Ⅰ ～ Ⅱ.These patients were divided into three groups using the random number table method: The mode of anesthesia is subarachnoid anesthesia.During postoperative analgesia,group D received ultrasound-guided sacral nerve block,group P received an ultrasound-guided pudendal nerve block,and group S received patient-controlled intravenous analgesia(PCIA)with 40 cases in each group.Group D: 30 min with 0.2% ropivacaine 20 ml for sacral nerve block before subarachnoid anesthesia.Group P: Bilateral pubic nerve block with 0.2% ropivacaine 20 ml 30 min before subarachnoid anesthesia.Group S:Direct single subarachnoid anesthesia and PCIA at the end of surgery.Heart rate(HR)and mean arterial pressure(MAP)were recorded at room entry(T0),30 min after the block operation(T1),immediately after the end of lumbar anesthesia in the prone position(T2),10 min after lumbar anesthesia(T3),and after surgery(T4).Record the level of anesthesia after the patient is transferred to the horizontal position at the end of lumbar anesthesia.Patients’ first postoperative pain time was recorded;resting and motor visual analog scores(VAS)were recorded at each time point of 6h(T5),12h(T6),24h(T7),36h(T8),and 48h(T9)postoperatively.Record the frequency and dose of analgesic drugs used within 48 h after surgery;record the onset and duration of nerve block in Group D and Group P patients;record whether patients had adverse reactions,such as pruritus,nausea,vomiting,urinary retention,etc.The levels of prostaglandin E2(PGE2)and substance P in peripheral venous blood were recorded at 6h and 24 h postoperatively.Results:1.There was no significant difference in HR and MAP among the three groups at different time points.Compared with T0 time points,there was no significant difference in HR and MAP between the D group and P group T1 time point,and there was no significant difference in anesthesia level among the three groups.2.The onset of block in group D was significantly faster than that in group P(P< 0.01),and the duration of block in group D was significantly shorter than that in group P(P < 0.01).3.There was no significant difference in the recovery time of lower limb muscle strength among the three groups.The time of first postoperative pain in group S was earlier than that in group D and group P(P < 0.05).Compared with groups D and P,the frequency of postoperative use of analgesics in group S was significantly higher than that in group D and group P(P < 0.05).4.At T5,the VAS scores of rest and exercise in group S were higher than those in group D and P,while those in group P were higher than those in group D,and there was a significant difference among the three groups at T6 and T7.At T6 and T7,the resting and exercise VAS scores in group S were higher than those in groups D and P,while the score in group P was lower than that in group D,and there was a significant difference among the three groups.There was no significant difference in resting and exercise VAS scores among the three groups at T8 and T9.5.The incidence of postoperative nausea and vomiting in group S was higher than that in group D and group P(P < 0.05).There was no significant difference in the incidence of other complications among the three groups(P < 0.05).The total incidence of complications in Group D was higher than that in Group P,and that in Group S was higher than that in Group D and Group P(P < 0.05).6.6 hours after the operation,the level of prostaglandin E2 in group S and 24 h S was significantly higher than that in group D and P,and the level of prostaglandin E2 in group S was significantly higher than that in group D and group P at 6 hours after the operation.Conclusion:Ultrasound-guided sacral nerve block and pudendal nerve block in anorectal surgery can reduce the production of pain factors prostaglandin E2(PGE2)and substance P and have a good effect on postoperative analgesia.Sacral nerve block is more effective in controlling early postoperative pain,but its duration is short.Pudendal nerve block can continuously reduce postoperative pain,and its complications are less than sacral nerve block.Both sacral nerve block and pudendal nerve block can be used for postoperative analgesia in anorectal surgery,which can effectively reduce postoperative pain and has more unique advantages than conventional postoperative PCIA.