Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method study

Background and Aims: The femoral nerve (FN) is commonly blocked using ropivacaine to provide postoperative analgesia after knee surgery. However, the minimal required concentration has not yet been defined. The aim of this study was to estimate the minimal ropivacaine concentration required to achie...

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Main Authors: Ahmed M. Taha, Manjusha Mohanan, Sebastian Orduna, Ahmed F. Alalwi, Mohamed I. Badr, Ahmed M. Abd-Elmaksoud
Format: Article
Language:English
Published: Wolters Kluwer Medknow Publications
Series:Indian Journal of Anaesthesia
Subjects:
Online Access:https://journals.lww.com/10.4103/ija.ija_806_24
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author Ahmed M. Taha
Manjusha Mohanan
Sebastian Orduna
Ahmed F. Alalwi
Mohamed I. Badr
Ahmed M. Abd-Elmaksoud
author_facet Ahmed M. Taha
Manjusha Mohanan
Sebastian Orduna
Ahmed F. Alalwi
Mohamed I. Badr
Ahmed M. Abd-Elmaksoud
author_sort Ahmed M. Taha
collection DOAJ
description Background and Aims: The femoral nerve (FN) is commonly blocked using ropivacaine to provide postoperative analgesia after knee surgery. However, the minimal required concentration has not yet been defined. The aim of this study was to estimate the minimal ropivacaine concentration required to achieve adequate analgesic FN block in 90% of cases (EC90). Methods: This study included 50 patients who were scheduled for knee ligament reconstruction under combined nerve block and general anaesthesia. The FN block was performed using 15 mL of ropivacaine with varying concentrations and considered adequate when associated with pain-free recovery. The sciatic, obturator, and lateral femoral cutaneous nerves were blocked to negate other knee pain generators, and their block success was confirmed. We used the biased-coin design up–down sequential method where the adequacy of an FN block altered the ropivacaine concentration used for the next block. The adequacy of the analgesic block or lack of it was analysed to calculate the analgesic EC90. The quadriceps motor power and morphine requirement were also recorded. Results: The recommended analgesic ropivacaine EC90 was 0.05% w/v. The associated quadriceps weakness and morphine requirement were minimal. Conclusion: FN block using ropivacaine 0.05% w/v may provide adequate analgesia in 90% of patients.
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institution Kabale University
issn 0019-5049
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language English
publisher Wolters Kluwer Medknow Publications
record_format Article
series Indian Journal of Anaesthesia
spelling doaj-art-7d88d147783b4bf5a626d5e70357de1f2025-02-06T09:46:41ZengWolters Kluwer Medknow PublicationsIndian Journal of Anaesthesia0019-50490976-281769221421910.4103/ija.ija_806_24Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method studyAhmed M. TahaManjusha MohananSebastian OrdunaAhmed F. AlalwiMohamed I. BadrAhmed M. Abd-ElmaksoudBackground and Aims: The femoral nerve (FN) is commonly blocked using ropivacaine to provide postoperative analgesia after knee surgery. However, the minimal required concentration has not yet been defined. The aim of this study was to estimate the minimal ropivacaine concentration required to achieve adequate analgesic FN block in 90% of cases (EC90). Methods: This study included 50 patients who were scheduled for knee ligament reconstruction under combined nerve block and general anaesthesia. The FN block was performed using 15 mL of ropivacaine with varying concentrations and considered adequate when associated with pain-free recovery. The sciatic, obturator, and lateral femoral cutaneous nerves were blocked to negate other knee pain generators, and their block success was confirmed. We used the biased-coin design up–down sequential method where the adequacy of an FN block altered the ropivacaine concentration used for the next block. The adequacy of the analgesic block or lack of it was analysed to calculate the analgesic EC90. The quadriceps motor power and morphine requirement were also recorded. Results: The recommended analgesic ropivacaine EC90 was 0.05% w/v. The associated quadriceps weakness and morphine requirement were minimal. Conclusion: FN block using ropivacaine 0.05% w/v may provide adequate analgesia in 90% of patients.https://journals.lww.com/10.4103/ija.ija_806_24anaesthesiaanaesthetics localanalgesiafemorallower limbregionalropivacaineultrasound
spellingShingle Ahmed M. Taha
Manjusha Mohanan
Sebastian Orduna
Ahmed F. Alalwi
Mohamed I. Badr
Ahmed M. Abd-Elmaksoud
Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method study
Indian Journal of Anaesthesia
anaesthesia
anaesthetics local
analgesia
femoral
lower limb
regional
ropivacaine
ultrasound
title Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method study
title_full Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method study
title_fullStr Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method study
title_full_unstemmed Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method study
title_short Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method study
title_sort minimum effective concentration 90 ec90 of ropivacaine for femoral nerve block a biased coin up and down sequential method study
topic anaesthesia
anaesthetics local
analgesia
femoral
lower limb
regional
ropivacaine
ultrasound
url https://journals.lww.com/10.4103/ija.ija_806_24
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