Yan-Lei Tai1, Li Peng1, Ying Wang2, Zi-Jun Zhao3, Ya-Nan Li1, Chun-Ping Yin1, Zhi-Yong Hou4, De-Cheng Shao5, Ya-Hui Zhang1, Qiu-Jun Wang1. 1. Department of Anesthesiology, Third Hospital Affiliated to Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China. 2. Department of Anesthesiology, Tangshan Gongren Hospital, Tangshan, Hebei, People's Republic of China. 3. Department of Anesthesiology, Hebei Chest Hospital, Shijiazhuang, Hebei, People's Republic of China. 4. Center of Emergency and Trauma, Third Hospital Affiliated to Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China. 5. Department of Sport Medicine, Third Hospital Affiliated to Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.
Abstract
Background: Femoral nerve block combined with general anesthesia is commonly used for patients undergoing knee arthroscopy in ambulatory care centers. An ideal analgesic agent would selectively (differentially) block sensory fibers, with little or no effect on motor nerves. Ropivacaine is considered to cause less motor block than others. This study investigated the median effective concentration (EC50) of ropivacaine for differential femoral nerve block in adults either younger or older than 60 years. Methods: Patients with American Society of Anesthesiologists physical status I-III and scheduled for knee arthroscopy were categorized as 18- to 60-years-old (Group 1), or older than 60 years (Group 2). Surgeries were performed under general anesthesia combined with femoral nerve block via 22 mL ropivacaine. The EC50 of ropivacaine for differential femoral nerve block was determined using the up-and-down method and probit regression. The primary outcome was the EC50 (95% confidence interval [CI]) of the 2 groups. Data on the sensory block, analgesic effect, complications, and hemodynamics during surgery were also recorded. Results: The EC50 of 22 mL ropivacaine for differential femoral nerve block of Group 1 (0.124%, 95% CI 0.097-0.143%) was significantly higher than that of Group 2 (0.088%, 95% CI 0.076-0.103%). The sensory block and hemodynamic data of the 2 groups were comparable. None of the patients experienced neurological complications. Conclusion: The EC50 of ropivacaine administered for differential femoral nerve block during knee arthroscopy was lower in patients older than 60 years, relative to younger adults.
Background: Femoral nerve block combined with general anesthesia is commonly used for patients undergoing knee arthroscopy in ambulatory care centers. An ideal analgesic agent would selectively (differentially) block sensory fibers, with little or no effect on motor nerves. Ropivacaine is considered to cause less motor block than others. This study investigated the median effective concentration (EC50) of ropivacaine for differential femoral nerve block in adults either younger or older than 60 years. Methods: Patients with American Society of Anesthesiologists physical status I-III and scheduled for knee arthroscopy were categorized as 18- to 60-years-old (Group 1), or older than 60 years (Group 2). Surgeries were performed under general anesthesia combined with femoral nerve block via 22 mL ropivacaine. The EC50 of ropivacaine for differential femoral nerve block was determined using the up-and-down method and probit regression. The primary outcome was the EC50 (95% confidence interval [CI]) of the 2 groups. Data on the sensory block, analgesic effect, complications, and hemodynamics during surgery were also recorded. Results: The EC50 of 22 mL ropivacaine for differential femoral nerve block of Group 1 (0.124%, 95% CI 0.097-0.143%) was significantly higher than that of Group 2 (0.088%, 95% CI 0.076-0.103%). The sensory block and hemodynamic data of the 2 groups were comparable. None of the patients experienced neurological complications. Conclusion: The EC50 of ropivacaine administered for differential femoral nerve block during knee arthroscopy was lower in patients older than 60 years, relative to younger adults.
Authors: Peter Gerner; Shi Hua Luo; Zhi-Ye Zhuang; Alimorad G Djalali; Anthony M Zizza; Robert R Myers; Ging Kuo Wang Journal: Reg Anesth Pain Med Date: 2005 Jul-Aug Impact factor: 6.288
Authors: Linda S Polley; Malachy O Columb; Norah N Naughton; Deborah S Wagner; Cosmas J M van de Ven; Kathryn H Goralski Journal: Anesthesiology Date: 2003-12 Impact factor: 7.892