Effect of Body-mass Index (BMI) on Median Effective Dose of Intrathecal Hyperbaric Bupivacaine

The Effect of BMI on Median Effective Dose (ED50) of Intrathecal Hyperbaric Bupivacaine for Total Knee Replacement Arthroplasty

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01291186

Enrollment

108

Registered

2011-02-08

Start date

2010-01-31

Completion date

2010-12-31

Last updated

2011-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Arthroplasty, Knee

Keywords

spinal anesthesia, intrathecal bupivacaine, median effective dose, height

Brief summary

The effect of Body-mass index (BMI) on requirements of local anesthetics used in spinal anesthesia has not been well established. The investigators tried to quantify the effect of BMI on spinal anesthesia by comparing the median effective dose of intrathecal bupivacaine between two different BMI groups.

Detailed description

The effect of BMI on requirements of local anesthetics used in spinal anesthesia has not been well established. The investigators tried to quantify the effect of BMI on spinal anesthesia by comparing the median effective dose (ED50)of intrathecal bupivacaine between two different BMI groups. The investigators determined the ED50 and ED 95 of intrathecal hyperbaric bupivacaine of subjects with BMI below 27.5 kg/m2, and subjects with BMI over 27.5 kg/m2, respectively. By comparing the difference of ED50 and ED95 between the groups, the investigators tried to quantify the effect of BMI on the bupivacaine dose requirement.

Interventions

DRUGBPV6NO

intrathecal bupivacaine 6 mg for BMI less than 27.5 kg/m2

DRUGBPV7NO

intrathecal bupivacaine 7 mg for BMI less than 27.5 kg/m2

DRUGBPV8NO

intrathecal bupivacaine 8 mg for BMI less than 27.5 kg/m2

DRUGBPV9NO

intrathecal bupivacaine 9 mg for BMI less than 27.5 kg/m2

DRUGBPV10NO

intrathecal bupivacaine 10 mg for BMI less than 27.5 kg/m2

DRUGBPV11NO

intrathecal bupivacaine 11 mg for BMI less than 27.5 kg/m2

DRUGBPV6O

intrathecal bupivacaine 6 mg for BMI over 27.5 kg/m2

DRUGBPV7O

intrathecal bupivacaine 7 mg for BMI over 27.5 kg/m2

DRUGBPV8O

intrathecal bupivacaine 8 mg for BMI over 27.5 kg/m2

DRUGBPV9O

intrathecal bupivacaine 9 mg for BMI over 27.5 kg/m2

DRUGBPV10O

intrathecal bupivacaine 10 mg for BMI over 27.5 kg/m2

DRUGBPV11O

intrathecal bupivacaine 11 mg for BMI over 27.5 kg/m2

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Masking

DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender

ALL

Age

40 Years to 80 Years

Healthy volunteers

Inclusion criteria

* Patients undergoing elective total knee replacement arthroplasty

Exclusion criteria

* Patients with previous spine surgery, diabetic and other neuropathy, skin infection at the site of injection, allergy to bupivacaine and other common contraindications for spinal anesthesia were excluded from this study. * The patients with height less than 140 cm or more than 160 cm, body-mass index (BMI) less than 20 or greater than 35 were also excluded.

Design outcomes

Primary

Measure	Time frame	Description
success of spinal anesthesia	every ten minutes during the surgery	a bilateral T12 sensory level to pinprick within 10 min of the intrathecal drug administration with no additional epidural anesthetics required during the surgery

Secondary

Measure	Time frame	Description
time to first request for supplemental analgesia	every ten minutes during and after surgery	for failure cases: it is the time of failure for success cases : it is the time of first postoperative pain

Countries

South Korea

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026