Objective The aim of this study was to determine the effective concentration of epidural ropivacaine for analgesia in 50% of parturients (EC50) in the first stage of labor. Methods Thirty-three ASA Ⅰ -　Ⅱ nulliparous women with 2-3 cm cervical dilatation who requested epidural analgesia were enrolled in the study. Epidural catheter was placed at L3-4 and advanced for 3-4 cm in the epidural space in a cephalad direction. 20 ml of ropivacaine solution of which the EC50 was being tested was given through the catheter into epidural space. The EC50 was determined by up-and-down sequential experiment. The initial concentration of the epidural ropivacaine being tested was decided to be 0.15% . If effective the next parturient received ropivacaine of a lower concentration; if ineffective the concentration of ropivacaine was increased in the next parturient. Each time the concentration of epidural ropivacaine increased/decreased by 0.01% . Analgesia was assessed by VAS score (1-10) . If VAS score was less than 3 within 30 min of ropivacaine administration, analgesia was defined as effective.Results Among the 33 parturients enrolled, three were excluded from the study because of uncertain analgesic efficacy. The results showed that the EC50 of epidural ropivacaine for analgesia in the first stage of labor was 0.063% [95% confidence interval (CI) was 0.05972%-0.06688%] .Conclusion The EC50 epidural ropivacaine for analgesia in the first stage of labor is 0.063 % determined by sequential experiment method.

Objective To improve early diagnosis of testicular torsion,reduce misdiagnosis and reduce the rate of orchiectomy.Methods The diagnosis and treatment of testicular torsion in 31 cases were retrospectively ana-lyzed.Results 54.8% misdiagnosis rate was in this group,all the 31 cases were diagnosed by color Doppler ultra-sound,including 19 cases of retained testicle and orchiectomy in 12 cases (38.7%).In 19 cases of this group retained testis,testicular torsion time within 5 hours was 2 cases,and postoperative had testicles survival.In the 6 cases of testicular torsion time within 5 hours to 10 hours,5 cases had the testis survival.In the 5 cases of torsion of testis time was 10 hours to 24 hours,3 caseshad the testis survival.In the 6 cases of testicular torsion time more than 24 hours,2 cases of testis survival.After postoperative following-up,19 cases of retained testis had no recurrence,all the 31 cases were found no contralateral testicular torsion and all cases sex hormone levels were in the normal levels. Conclusion Testicular torsion is easily misdiagnosed,color doppler ultrasound should be preferred.Early diagnosis and aggressive surgical exploration,unity and strictly control the orchiectomy surgery indications,means a lot to reduce the rate of orchiectomy.