Intrathecal Dexmedetomidine With Bupivacaine for Spinal Anesthesia in Cesarean Section

Study Overview
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Brief Summary
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A Randomized, Controlled, Double blind study aiming to evaluate the analgesic potentials and side effect profile of different dose levels of Dexmedetomidine added to subarachnoid bupivacaine in full-term pregnant women undergoing elective cesarean section using spinal anesthesia. The investigators ultimate goal is to find out the least effective dose which will be associated with minimal or no side effects. The primary outcome will be the time to two sensory block segment regression.

Detailed Description
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Alpha 2-agonists are non-opioid adjuvants with a significant role in extending the analgesic duration of subarachnoid block. When clonidine or Dexmedetomidine was added to intrathecal local anesthetics, the regression of sensory and motor blocks increased dose-dependently. Further, a recent meta-analysis including seven randomized controlled studies reported an increase in the duration of analgesia and reduced morphine requirement after the concomitant subarachnoid administration of clonidine. Animal studies demonstrated that Dexmedetomidine added to bupivacaine significantly enhanced the duration of sensory and motor blockade of sciatic nerve block. Histo-pathological examination proved that all of the nerves analyzed had normal axons and myelin at 24 h and 14 days after the peri-neural administration of Dexmedetomidine. Several clinical studies confirmed the analgesic potentials and safe neurological outcome of neuraxially administered Dexmedetomidine in the non-obstetric settings while intrathecal clonidine proved to be a useful analgesic adjunct for spinal anesthesia in patients undergoing cesarean section. But to the best of the investigator knowledge the effects of intrathecal Dexmedetomidine on the perioperative clinical profile of bupivacaine-induced spinal anesthesia were not studied before in the obstetric patient population.

Official Title
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Effects of Intrathecal Dexmedetomidine on the Perioperative Clinical Profile of Bupivacaine-induced Spinal Anesthesia for Cesarean Section

Conditions
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Anesthesia, Spinal

Intervention / Treatment
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* Drug: Dexmedetomidine & Bupivacaine.
* Drug: Bupivacaine Only.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Full-term pregnant women. Elective cesarean section using spinal anesthesia. Singleton gestation. American Society of Anesthesiologists (ASA) physical status classes I and II. Exclusion Criteria: Preterm pregnancy (<37 wks gestation). Multiple gestation. Cardiovascular disease (e.g., preeclampsia, hypertension) and the use of antihypertensive medication. Conditions that preclude spinal anesthesia. Failed spinal block and conversion to general anesthesia. A history of established chronic pain. Drug addiction. A psychiatric disorder. Inability to communicate effectively. Asthma and allergy to non-steroidal anti-inflammatory drugs.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 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: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: DEX-5<br>Dexmedetomidine & Bupivacaine. Patients will receive intrathecal 12.5 mg isobaric bupivacaine and 5 μg Dexmedetomidine using a total volume of injectate of 2.5 ml, and intrathecal injections will be given over approximately 10 to 15 seconds. | Drug: Dexmedetomidine & Bupivacaine.<br>* Intrathecal injection of Dexmedetomidine & Bupivacaine.<br>|
| Active Comparator: DEX-10<br>Dexmedetomidine & Bupivacaine. Patients will receive intrathecal 12.5 mg isobaric bupivacaine and 10 μg Dexmedetomidine using a total volume of injectate of 2.5 ml, and intrathecal injections will be given over approximately 10 to 15 seconds. | Drug: Dexmedetomidine & Bupivacaine.<br>* Intrathecal injection of Dexmedetomidine & Bupivacaine.<br>|
| Active Comparator: DEX-15<br>Dexmedetomidine & Bupivacaine. Patients will receive intrathecal 12.5 mg isobaric bupivacaine and 15 μg Dexmedetomidine using a total volume of injectate of 2.5 ml, and intrathecal injections will be given over approximately 10 to 15 seconds. | Drug: Dexmedetomidine & Bupivacaine.<br>* Intrathecal injection of Dexmedetomidine & Bupivacaine.<br>|
| Active Comparator: Control<br>Bupivacaine Only. Patients will receive intrathecal 12.5 mg isobaric bupivacaine only using a total volume of injectate of 2.5 ml, and intrathecal injections will be given over approximately 10 to 15 seconds. | Drug: Bupivacaine Only.<br>* Intrathecal injection of Bupivacaine only.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The time to two sensory block segment regression. | Define the start of regression of the level of sensory block | 70 min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The peak sensory level of the block. | By Pin Prick testing. | 10 min | 
| Time from intrathecal injection to peak sensory block level. | Define the speed of onset of the block. | 10 min | 
| Time to S1 level sensory regression. | Define duration of the block. | 70 min | 
| Degree of motor block. | By Modified Bromage Score. | 24 h | 
| Intraoperative hemodynamic variables. | Detect frequency of side effects | 24 h | 
| The total dose of ephedrine/atropine required to maintain hemodynamic stability. | Detect frequency of side effects | 24 h | 
| The amount of lactated Ringer's solution required intraoperatively to maintain normal Blood pressure range | Detect frequency of side effects | 24 h | 
| Oxygen saturation (the need for O2 supplementation) | Detect frequency of side effects | 24 h | 
| Intraoperative analgesic supplementation | Define quality of the block | 70 min | 
| Time to first postoperative rescue analgesic request | Define duration of analgesia by the block | 24 h | 
| Postoperative pain scores for 24 hours | Define duration of analgesia by the block | 24 h | 
| Frequency of administration of postoperative analgesics | Define duration of analgesia by the block | 24 h | 
| Intraoperative sedation scores | Detect frequency of side effects | 24 h | 
| Incidence of side effects (nausea, vomiting, shivering, pruritus, respiratory depression, and desaturation) | Detect frequency of side effects | 24 h | 
| New born Apgar Score | Detect any effects on the new born at different dose levels | 5 min | 
| Duration of motor block. | By Modified Bromage Score. | 24 h | 
| Early postoperative hemodynamic variables. | Detect frequency of side effects | 24 h | 
| Total dose of postoperative analgesics | Define duration of analgesia by the block | 24 h | 
| Postoperative sedation scores | Detect frequency of side effects | 24 h | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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spinal anesthesia, caesarian section, Dexmedetomidine