Does the Addition of Epinephrine Prolong the Duration of Spinal Anesthesia for Repeat Cesarean Section?

Study Overview
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Brief Summary
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The purpose of this study is to investigate whether the addition of a medication called epinephrine to spinal medications prolongs the duration of the anesthesia. The medication standardly used in spinal anesthesia is a local anesthetic (bupivacaine) and an opiate pain medication (morphine). These medications typically last about 2 hours. The investigators want to determine if adding epinephrine to the spinal medications prolongs the anesthetic without side effects. A longer duration of anesthesia may be useful in prolonged repeat cesarean section. Epinephrine is known to prolong the action of some local anesthetics, but the investigators want to specifically study combining it with the medications the investigators use regularly for cesarean section. You may qualify to take part in this research study because you are having a repeat cesarean section. Repeat cesarean sections sometimes last longer than 2 hours. The investigators want to determine if epinephrine will prolong the anesthetic.

Detailed Description
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Spinal anesthesia with bupivacaine is a commonly used anesthetic in the obstetric population. It is most frequently carried out as a single shot intrathecal injection. This method can be utilized for both labor analgesia and surgical anesthesia for cesarean section. One of the concerns in using a single shot spinal injection for surgical anesthesia is the duration of adequate surgical conditions. This concern is especially relevant to repeat cesarean sections, as each subsequent procedure has the potential to be more complex than the prior and, therefore, prolonged. A reliable way to prolong surgical anesthesia provided by single shot spinal injection of bupivacaine could prove invaluable in the setting of repeat cesarean section. It has been well documented that adding epinephrine to intrathecal lidocaine will increase its duration1, but the evidence for augmenting the duration of anesthesia provided by adding epinephrine to bupivacaine is much more equivocal and less robust. This is a randomized control trial investigating whether or not adding epinephrine to a standard single intrathecal injection of hyperbaric bupivacaine for repeat cesarean will prolong its duration. It will be investigated using women who are undergoing scheduled repeat cesarean section in whom neuraxial anesthesia is the appropriate primary anesthetic. The investigators will compare the onset, quality and duration of both sensory and motor components of the spinal block as well as the incidence of known side effects.

Official Title
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Does the Addition of Epinephrine Increase the Duration of Intrathecal Hyperbaric Bupivacaine for Repeat Cesarean Section?

Conditions
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Spinal Anesthesia, Cesarean Section

Intervention / Treatment
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* Drug: Low-dose epinephrine
* Drug: High-dose epinephrine
* Drug: No epinephrine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Non-emergent repeat cesarean section Neuraxial anesthesia as the planned primary anesthetic Informed consent obtained Females age 18-50 Exclusion Criteria: Emergency cesarean section Anesthetic other than neuraxial Allergy to local anesthetics, morphine, or epinephrine Pre-existing sensory/motor deficit

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low-dose epinephrine<br>100micrograms of epinephrine group | Drug: Low-dose epinephrine<br>* 0.1ml of preservative-free saline and 0.1ml of 1:1000 epinephrine will be added to the standard spinal medications<br>|
| Experimental: High-dose epinephrine<br>200micrograms of epinephrine group | Drug: High-dose epinephrine<br>* 0.2ml of 1:1000 epinephrine will be added to the standard spinal medications<br>* Other names: adrenaline;|
| Placebo Comparator: No epinephrine<br>0.2ml saline | Drug: No epinephrine<br>* 0.2ml of preservative-free saline will be added to the standard spinal medications<br>* Other names: preservative-free saline;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensory Recovery | Time to T10 sensory recovery as measured by pinprick sensation | up to 3 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Motor Recovery | Time to Bromage 3 motor recovery | up to 4 hours | 
| Block Onset | Time to a onset of T4 level of anesthesia or the highest level achieved in 15min | up to 15 min | 
| Number of Participants With Hypotension | Incidence of hypotension as measured by participants needing vasopressor agents | at 2 minutes and at 25 minutes | 
| Adequacy of Anesthesia | As measured by pinprick sensation and/or patient discomfort as measured by verbal pain score on a scale of 0=no pain to 10=worst imaginable pain, obtained within 3 hours of receiving anesthesia. | up to 3 hrs | 
| Patient Satisfaction | Patient satisfaction score was elicited upon arrival to the recovery room on a 1-5 Likert scale. Number of participants selecting the highest score of 5 or completely satisfied. | up to 3 hours | 
| Incidence of Nausea and Vomiting |  | up to 3 hours | 
| Incidence of Pruritus | data not collected | up to 3 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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spinal anesthesia, epinephrine, bupivacaine, repeat cesarean