A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia
Abstract Background Intravenous regional anesthesia is an easy and reliable anesthetic technique, but its use is limited by tourniquet pain. Clonidine is effective in overcoming this shortcoming when used with intravenous regional anesthesia at a dose of 1 μg/kg. Dexmedetomidine has also been used s...
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| Format: | Article |
| Language: | English |
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BMC
2022-05-01
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| Series: | BMC Anesthesiology |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12871-022-01702-9 |
| _version_ | 1811254235900149760 |
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| author | Cynthia Karam Sadek Al Assadi Ghassan Kanazi Carine Zeeni |
| author_facet | Cynthia Karam Sadek Al Assadi Ghassan Kanazi Carine Zeeni |
| author_sort | Cynthia Karam |
| collection | DOAJ |
| description | Abstract Background Intravenous regional anesthesia is an easy and reliable anesthetic technique, but its use is limited by tourniquet pain. Clonidine is effective in overcoming this shortcoming when used with intravenous regional anesthesia at a dose of 1 μg/kg. Dexmedetomidine has also been used successfully at a dose of 0.5 μg/kg. Objective Based on the potency ratios of clonidine and dexmedetomidine (8 to 1) we hypothesize that a lower dexmedetomidine dose would provide patients with 50 min of pain free tourniquet time. Methods After informed consent, patients received intravenous regional anesthesia with lidocaine and dexmedetomidine following a sequential allocation scheme. The first patient received a dose of 0.5 μg/kg of dexmedetomidine. The dose was then adjusted in 0.1 μg/kg gradients for the following patients depending on the success of the previous block. If a patient experienced tourniquet pain prior to 50 min, the next patient received a higher dose. If not, the dose was decreased. Recruitment continued until 6 independent crossovers were observed with a minimum of 20 patients. The median effective dose ED50 of dexmedetomidine was calculated using the modified up-and-down method. Main outcome measures The median effective dose of dexmedetomidine (ED50) that provides 50 min of tolerance to the tourniquet during a lidocaine intravenous regional anesthesia by a sequential Dixon up-and-down allocation study. Results The ED50 of dexmedetomidine that provided 50 min of tolerance to the tourniquet was 0.30 ± 0.06 μg/kg. Conclusion We determined that the dexmedetomidine dose necessary to provide 50 min of pain free tourniquet time during intravenous regional anesthesia was higher than expected based on the relative alpha-2 adrenergic receptor selectivity of dexmedetomidine compared to clonidine. Trial registration Clinicaltrials.gov: Retrospectively registered ( NCT05342870 ; registration date: 25/04/2022). |
| first_indexed | 2024-04-12T17:04:16Z |
| format | Article |
| id | doaj.art-5611794eea2f416195e82e0fa3964f1c |
| institution | Directory Open Access Journal |
| issn | 1471-2253 |
| language | English |
| last_indexed | 2024-04-12T17:04:16Z |
| publishDate | 2022-05-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Anesthesiology |
| spelling | doaj.art-5611794eea2f416195e82e0fa3964f1c2022-12-22T03:23:59ZengBMCBMC Anesthesiology1471-22532022-05-012211710.1186/s12871-022-01702-9A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesiaCynthia Karam0Sadek Al Assadi1Ghassan Kanazi2Carine Zeeni3Department of Anesthesiology and Pain Management, American University of Beirut Medical CenterDepartment of Anesthesiology and Pain Management, American University of Beirut Medical CenterDepartment of Anesthesiology and Pain Management, American University of Beirut Medical CenterDepartment of Anesthesiology and Pain Management, American University of Beirut Medical CenterAbstract Background Intravenous regional anesthesia is an easy and reliable anesthetic technique, but its use is limited by tourniquet pain. Clonidine is effective in overcoming this shortcoming when used with intravenous regional anesthesia at a dose of 1 μg/kg. Dexmedetomidine has also been used successfully at a dose of 0.5 μg/kg. Objective Based on the potency ratios of clonidine and dexmedetomidine (8 to 1) we hypothesize that a lower dexmedetomidine dose would provide patients with 50 min of pain free tourniquet time. Methods After informed consent, patients received intravenous regional anesthesia with lidocaine and dexmedetomidine following a sequential allocation scheme. The first patient received a dose of 0.5 μg/kg of dexmedetomidine. The dose was then adjusted in 0.1 μg/kg gradients for the following patients depending on the success of the previous block. If a patient experienced tourniquet pain prior to 50 min, the next patient received a higher dose. If not, the dose was decreased. Recruitment continued until 6 independent crossovers were observed with a minimum of 20 patients. The median effective dose ED50 of dexmedetomidine was calculated using the modified up-and-down method. Main outcome measures The median effective dose of dexmedetomidine (ED50) that provides 50 min of tolerance to the tourniquet during a lidocaine intravenous regional anesthesia by a sequential Dixon up-and-down allocation study. Results The ED50 of dexmedetomidine that provided 50 min of tolerance to the tourniquet was 0.30 ± 0.06 μg/kg. Conclusion We determined that the dexmedetomidine dose necessary to provide 50 min of pain free tourniquet time during intravenous regional anesthesia was higher than expected based on the relative alpha-2 adrenergic receptor selectivity of dexmedetomidine compared to clonidine. Trial registration Clinicaltrials.gov: Retrospectively registered ( NCT05342870 ; registration date: 25/04/2022).https://doi.org/10.1186/s12871-022-01702-9Bier blockDexmedetomidineTourniquet painDixon up-and-down method |
| spellingShingle | Cynthia Karam Sadek Al Assadi Ghassan Kanazi Carine Zeeni A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia BMC Anesthesiology Bier block Dexmedetomidine Tourniquet pain Dixon up-and-down method |
| title | A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia |
| title_full | A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia |
| title_fullStr | A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia |
| title_full_unstemmed | A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia |
| title_short | A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia |
| title_sort | sequential allocation study to determine the ed50 of dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia |
| topic | Bier block Dexmedetomidine Tourniquet pain Dixon up-and-down method |
| url | https://doi.org/10.1186/s12871-022-01702-9 |
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