Clinical trial NCT02102607: Effect of Age on the Median Effective Dose(ED50) for Motor Block With Intrathecal Ropivacaine
Official title: Effect of Age on the Median Effective Dose(ED50) for Motor Block With Intrathecal Ropivacaine
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Anesthesia
Keywords: intrathecal; ropivacaine; motor blockade; local anesthetics
Lead sponsor: China Three Gorges University, Yichang, China
Sponsor class: OTHER
First posted: 2014-04-03
Enrollment: 120
Sex: ALL
Minimum age (years): 20
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Adult patients who were undergoing transurethral, urological or lower limb surgery, primarily under the spinal anesthesia

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: the dose of intrathecal ropivacaine
timeFrame: at 5-min after administered ropivacaine
Secondary outcomes:
Other outcomes:
Locations:
city: Yichang
country: China
facility: China Three Gorges University
state: Hubei
Study officials:
affiliation: China Three Gorges University
name: jun yang, PhD
role: STUDY_DIRECTOR
References:
citation: 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.
citation: 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.