Effect of Age on the Median Effective Dose(ED50) for Motor Block With Intrathecal Ropivacaine

Overview

The primary aim of this study was to determine the median effective dose (ED50) for motor block of intrathecally-administered ropivacaine in adults (20-80 years), and to assess the effect of age on ED50 required for motor block.

Study Type

  • Study Type: Observational
  • Study Primary Completion Date: March 2015

Detailed Description

This study was performed in adult patients undergoing transurethral, urological or lower limb surgery under combined spinal and epidural anesthesia. Patients were stratified according to age: 20-30, 31-40, 41-50, 51-60, 61-70, and 71-80 years. The spinal component of the anesthetic was established by bolus administration of various up-and-down doses of 0.75% ropivacaine, determined by Dixon's method, with the first patient receiving 15 mg, and with testing intervals of 1.5 mg according to failure or success of the preceding patient's motor block. The degree of motor block after intrathecal administration of each dose was evaluated by the modified Bromage and Hip motor function score. The primary outcome was obtained by administration of the mean dosage that was determined from the midpoints of all independent pairs of patients involving a crossover from failure to success during 5 minutes after the spinal injection. The ED50 were estimated from the up-and-down sequences using the method of Dixon and Massey and logistic regression. Other endpoints were included on the basis of sensory block level, duration of motor blockade, hypotension, and vasopressor requirements.

Interventions

  • Other: age
    • subjects stratified according to age: 20-30 years (Group 1), 31-40 years (Group 2), 41-50 years (Group 3), 51-60 years (Group 4), 61-70 years (Group 5), and 71-80 years (Group 6).

Arms, Groups and Cohorts

  • age
    • subjects stratified according to age: 20-30 years (Group 1), 31-40 years (Group 2), 41-50 years (Group 3), 51-60 years (Group 4), 61-70 years (Group 5), and 71-80 years (Group 6).

Clinical Trial Outcome Measures

Primary Measures

  • the dose of intrathecal ropivacaine
    • Time Frame: at 5-min after administered ropivacaine

Participating in This Clinical Trial

Inclusion Criteria

  • Adult patients who were undergoing transurethral, urological or lower limb surgery, primarily under the spinal anesthesia Exclusion Criteria:

  • Patients with diabetes, obesity, neuromuscular diseases, bleeding diathesis, hypersensitivity to amide local anesthetics, lumbar vertebrae abnormality, chronic back pain, or who were pregnant

Gender Eligibility: All

Minimum Age: 20 Years

Maximum Age: 80 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • China Three Gorges University, Yichang, China
  • Provider of Information About this Clinical Study
    • Principal Investigator: Mingquan Chen, the First College of Clinical Medical Science, China Three Gorges University (China) – China Three Gorges University, Yichang, China
  • Overall Official(s)
    • jun yang, PhD, Study Director, China Three Gorges University

References

Lee YY, Ngan Kee WD, Fong SY, Liu JT, Gin T. The median effective dose of bupivacaine, levobupivacaine, and ropivacaine after intrathecal injection in lower limb surgery. Anesth Analg. 2009 Oct;109(4):1331-4. doi: 10.1213/ane.0b013e3181b1912b.

Gupta R, Bogra J, Singh PK, Saxena S, Chandra G, Kushwaha JK. Comparative study of intrathecal hyperbaric versus isobaric ropivacaine: A randomized control trial. Saudi J Anaesth. 2013 Jul;7(3):249-53. doi: 10.4103/1658-354X.115326.

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