ED90 for Hyperbaric Bupivacaine in Super Obese Parturients

Study Overview
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Brief Summary
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The aim of this study is to determine the ED90 of hyperbaric intrathecal bupivacaine for the super obese population undergoing cesarean section under a combined spinal epidural technique.

Official Title
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ED90 for Hyperbaric Bupivacaine in Spinal Anesthesia for Cesarean Delivery in Super Obese Parturients

Conditions
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Obesity, Morbid, Spinal Anesthesia, Cesarean Delivery

Intervention / Treatment
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* Drug: Bupivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiology (ASA) class 2 and 3 English speaking Gestational age > 36 weeks Scheduled for cesarean delivery under combined spinal epidural anesthesia 18 years or older BMI > 50 kg/m2 Exclusion Criteria: History of past or current intravenous drug or chronic opioid abuse Allergy or contraindication to any study medications Intrapartum cesarean delivery under epidural anesthesia Cesarean delivery under general anesthesia

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: The starting dose of hyperbaric bupivacaine for the first patient in this study will be 9mg; the dose for the subsequent subject will be based on the response of the preceding subject as per the Narayana Rule, a modification of the biased-coin design (BCD) up-down sequential method (UDM).
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Starting dose of Bupivacaine (9 mg)<br>The starting dose of hyperbaric bupivacaine for the first patient in this study will be 9mg; the dose for the subsequent subject will be based on the response of the preceding subject as per the Narayana Rule, a modification of the biased-coin design (BCD) up-down sequential method (UDM). | Drug: Bupivacaine<br>* Determination of the dose will rely on the outcomes of the preceding 7 patients receiving the same dose, as the number of previous patients to consider is a function of the target dose. Among all patients who received a certain dose, a proportion of successful outcomes will be determined (P(d)); if P(d) <0.90, and at least one of the previous 7 patients who received the same dose had an unsatisfactory outcome, the next patient will receive a pre-determined increment of 0.75 mg of bupivacaine. Alternatively, if P(d) 0.90 and the previous 7 patients who received the same dose had successful outcomes, the next patient will receive a pre-determined decrement of 0.75mg of bupivacaine. Otherwise, the dose will remain the same.<br>|
| Experimental: Subsequent dose<br> | Drug: Bupivacaine<br>* Determination of the dose will rely on the outcomes of the preceding 7 patients receiving the same dose, as the number of previous patients to consider is a function of the target dose. Among all patients who received a certain dose, a proportion of successful outcomes will be determined (P(d)); if P(d) <0.90, and at least one of the previous 7 patients who received the same dose had an unsatisfactory outcome, the next patient will receive a pre-determined increment of 0.75 mg of bupivacaine. Alternatively, if P(d) 0.90 and the previous 7 patients who received the same dose had successful outcomes, the next patient will receive a pre-determined decrement of 0.75mg of bupivacaine. Otherwise, the dose will remain the same.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent of successful blocks for induction (success induction) | bilateral T6 sensory level to pinprick by | 10 minutes after intrathecal drug administration | 
| Percent of successful blocks for operation (success operation) | successful initial sensory level without requiring additional epidural anesthetic | during surgery up to 90 minutes after intrathecal injection | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Bupivacaine ED90, Cesarean Delivery, Obesity, Spinal Anesthesia