吗啡硬膜外镇痛剂量与患者术后尿潴留的关系

目的 评价吗啡硬膜外镇痛剂量与患者术后尿潴留的关系.方法 择期行膝关节镜手术的患者60例,年龄20～56岁,体重49～76 kg,性别不限,ASA Ⅰ级,随机分为3组(n=20),对照组(C组)硬膜外腔注射生理盐水5 ml;M1,2组硬膜外腔分别注射吗啡1和3 mg.采用Micro Maxx便携式超声仪测量患者膀胱尿量,记录术后产生排尿冲动时的膀胱尿量和首次排尿时间;于麻醉前和术后记录视觉模拟评分(VAS评分);记录术后尿潴留(膀胱尿量≥600 ml且30min内不能自行排尿)、恶心呕吐及瘙痒的发生情况.结果 与C组比较,M2组尿潴留发生率升高,VAS评分降低,M1,2组首次排尿时间延长,产生排尿冲动时的膀胱尿量增多,瘙痒发生率升高(P<0.05或0.01);与M1组比较,M2组尿潴留发生率升高、首次排尿时间延长,产生排尿冲动时的膀胱尿量增多,术后瘙痒发生率升高(P<0.05),VAS评分和镇痛有效率差异无统计学意义(P>0.05).结论 吗啡硬膜外剂量与患者术后尿潴留的发生有关,呈剂量依赖性,1 mg为推荐剂量.

Relationship between doses of epidural morphine for analgesia and postoperative urinary retention

Objective To investigate the relationship between the doses of epidural morphine administered for postoperative analgesia and postoperative urinary retention (POUR). Methods Sixty ASA Ⅰ patients aged < 20-56 yr undergoing atthroscopic knee operation under epidural anesthesia were randomly divided into 3 groups ( n = 20 each) : group Ⅰ and Ⅱ received epidural morphine 1 and 3 mg in 5 ml of normal saline (NS) respectively at the end of operation (group M1, M2 ); group Ⅲ received NS 5 ml instead of morphine (group C). Urinary retention was defined as the patient could not void, when bladder volume was ≥ 600 ml measured using ultrasound. Bladder urine volume was measured before anesthesia and at 4, 6, 8, 10 and 12 h after operation. The occurrence of urinary retention, the first postoperative voiding time, VAS scores and the incidences of vomiting and pruritus were recorded. Results The 3 groups were comparable with respect to age, M/F sex ratio, preoperative bladder urine volume, the amount of local anesthetic used during operation and duration. The incidences of urinary retention, vomiting and pruritus were 65%, 60% and 90% respectively in group M2 and significantly higher than those in the other 2 groups. The first postoperative voiding time was significantly longer in group M2 than in the other 2 groups. VAS scores were significantly lower in group M1 and M2 than in group C. There was no significant difference in VAS scores between group M1 and M2. Conclusion Epidural morphine increases the incidence of POUR in a dose-dependent manner, and 1 mg is the recommended dose.