Height Adjusted Versus Standardized Dose of Bupivacaine for Spinal Anesthesia

Study Overview
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Brief Summary
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General anesthesia during pregnancy is associated with several major risks including unanticipated difficult airway, pulmonary aspiration, and specific anesthetic effects on the newborn. Thus, intrathecal anesthesia is the technique of choice for cesarean section. Nevertheless, the main side effect of intrathecal anesthesia is arterial hypotension which depend mainly on the dose of local anesthetic administered intrathecally. To date there is no guidelines nor evidences whic help the anesthetist to precisely estimate the required dose. Most often a standardized dose of 8 to 10 mg of bupivacaine is administered. However, some data suggest that a lower dose may be administered resulting in less frequent arterial hypotension. Nevertheless, a well designed randomized study is lacking.

Detailed Description
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The present controlled randomized double blind trial was designed to compare 2 intrathecal dose of bupivacaine for cesarean section a standard dose of 10 mg of intrathecal bupivacaine associated with morphine 100 micrograms and sufentanil 3 micrograms a height-calculated dose of bupivacaine (0.05 mg per cm of height) on associated with morphine 100 micrograms and sufentanil 3 micrograms The main outcome is the rate of hypotension defined as a 20% or more decrease in systolic arterial pressure. Secondary outcomes focused on intrathecal anesthesia efficacy, success or failure and on interventions required to manage arterial hypotension

Official Title
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Height Adjusted Versus Standardized Dose of Bupivacaine in Spinal Anesthesia for Caesarean Delivery - A Randomized Double-blind Interventional Study

Conditions
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Regional Anesthesia Morbidity, Cesarean Section Complications, Local Anesthetic Complication

Intervention / Treatment
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* Other: standardized dose
* Other: adjusted dose


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: scheduled cesarean section with intrathecal anesthesia term pregnancy > 35 weeks signed informed consent Exclusion Criteria: unscheduled or emergent cesarean section any contra indication to intrathecal anesthesia any antihypertensive drug prescribed to control arterial pressure during pregnancy pre-eclampsia and eclampsia history of Marfan or Ehlers Danlos disease

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: randomized controlled double blind trial
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: control group<br>intrathecal administration of a solution containing bupivacaine 10 mg morphine 100 micrograms sufentanil 3 micrograms | Other: standardized dose<br>* intrathecal anesthesia with 10 mg of bupivacaine<br>* Other names: standardized dose of bupivacaine;|
| Experimental: individualized group<br>intrathecal administration of a solution containing bupivacaine 0.05 mg per cm of patient's height morphine 100 micrograms sufentanil 3 micrograms | Other: adjusted dose<br>* intrathecal anesthesia with 0.05 mg of bupivacaine par cm of patient's height<br>* Other names: adjusted dose of bupivacaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| rate of arterial hypotension | rate of arterial hypotension defined as a 20% or more decrease in systolic arterial pressure as compared with baseline systolic arterial pressure measured at 32 weeks | 4 hours since the start of intrathecal bupivacaine administration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| vasopressor total dose | total dose of vasopressor administered during intrathecal anesthesia | 4 hours since the start of intrathecal bupivacaine administration | 
| metameric level of intrathecal anesthesia | clinical evaluation of the metameric level obtained during intrathecal anesthesia | 4 hours since the start of intrathecal bupivacaine administration | 
| lower limb motor block at the end of the caesarean section | lower limb motor block at the end of the caesarean section using Bromage score | 5 min after the end of caesarean section at newborn umbilical cord clamp | 
| rate of need for general anesthesia | rate of need for general anesthesia because of intrathecal anesthesia failure or overdose | 5 min after the end of caesarean section at newborn umbilical cord clamp | 
| patient's comfort self evaluation | patient's comfort self evaluation using a verbal rating scale from 0 (uncomfortable) to 10 (totally comfortable) | 4 hours since the start of intrathecal bupivacaine administration | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cesarean section, intrathecal anesthesia, bupivacaine, morbidity