Estimation of the minimum effective dose of tramadol for postoperative analgesia in infants using the continual reassessment method

Tramadol is a potent analgesic.However,the analgesia efficacy of tramadol,particularly its minimum effective dose(MED),is not clear.The aim of this study is to find MED of tramadol for postoperative analgesia in infants.The continual reassessment method(CRM)was performed to find MED.Infants undergoing surgeries were included in the 3 phases of this series.In each phase,24 participants were allocated a different tramadol dose.Pain intensity was measured by face,legs,activity,cry,consolability(FLACC)measurement at 3-hour intervals.Tramadol was considered ineffective if the FLACC score was higher than 4 in 10 at anytime.In phase 1,seven dose levels were used within the range 0.1-0.4 mg·kg^(-1)·h^(-1).Phase 1 was insufficient to identify the MED,and we increased the dose to 0.4-0.8 mg·kg^(-1)·h^(-1) in phase 2.Phase 2 was insufficient to identify the MED.In phase 3,local anesthetic wound infiltration was introduced,and the tramadol dose levels tested were the same as in phase 1.The successful analgesia probability of tramadol 0.4 mg·kg^(-1)·h^(-1) was 82.1%(95%CI,0.742-0.925)in phase 1.In phase 2,it was 84.7%(95%CI,0.789-0.991)with the dose 0.8 mg·kg^(-1)·h^(-1).Phase 1 and phase 2 were insufficient to identify the MED.In phase 3,the successful analgesia probability for dose 0.35 mg·kg^(-1)·h^(-1) was 96.7%(95%CI,0.853-0.997).We have demonstrated that tramadol provides insufficient analgesia for surgeries considered to cause moderate-to-severe postoperative pain in infants if used as the sole analgesic,and that local anesthetic wound infiltration enhances the efficacy of tramadol.

Effects of Changing Relative Value of Mininimum Wages on Wage Distribution in China:Analysis Based on County-Level Data

On the basis of extending Lee's(1999) model, this paper resolves the problem of biased division in the specification of equation and employs Urban Household Survey(UHS) data,China Household Income Project(CHIP) data and county-level minimum wage data collected by authors to investigate the wage distribution effects of change in the effective minimum wages measured by relative value. The result shows that the effective minimum wage will exert a significant spillover effect on wage distribution at the40 th percentile and below, which is favorable to reducing wage gaps at the bottom. This conclusion holds true under various robustness tests. However, the shrinking effective minimum wage has created a downward drag on wages, thus widening wage gaps at the bottom. The shrinking effective minimum wage contributed 150%,53.8%,45.5% and16.7% to the wage gaps at the 10 th, 20 th, 30 th and 40 th percentiles compared with the 50 th percentile. Therefore, the key to ensuring the effectiveness of minimum wages lies in the implementation of an automatic adjustment mechanism correlated with macroeconomic indicators. Compliance with minimum wages must be guaranteed and change in minimum wages must be measured with relative value.