Surgical Anesthesia, Cesarean Section
Conditions
Brief summary
Regional anesthesia is commonly used for elective and emergency cesarean delivery. It provides numerous safety advantages when compared to general anesthesia for both the mother and fetus1. Epidurals also have the added benefit of being able to provide pain relief throughout labor and in the event of cesarean delivery, epidural analgesia can be extended to provide surgical anesthesia. Numerous studies have been performed to assess the onset times of various local anesthetics when administered through an epidural catheter. Attempts to reduce anesthetic onset time and improve the quality of intraoperative analgesia have been attempted by using different local anesthetic solutions and by the addition of other drugs to the epidural solution (such as epinephrine, fentanyl and sodium bicarbonate).
Detailed description
Regional anesthesia is commonly used for elective and emergency cesarean delivery. It provides numerous safety advantages when compared to general anesthesia for both the mother and fetus1. Epidurals also have the added benefit of being able to provide pain relief throughout labor and in the event of cesarean delivery, epidural analgesia can be extended to provide surgical anesthesia. Numerous studies have been performed to assess the onset times of various local anesthetics when administered through an epidural catheter. Attempts to reduce anesthetic onset time and improve the quality of intraoperative analgesia have been attempted by using different local anesthetic solutions and by the addition of other drugs to the epidural solution (such as epinephrine, fentanyl and sodium bicarbonate). A recent meta-analysis concluded that the optimum local anesthetic solution for extending a labor epidural from analgesia to surgical anesthesia has yet to be determined 2. In 1994, a retrospective study compared 1.5% lidocaine/bicarbonate/epinephrine mixture to 3% chloroprocaine in parturients with pre-existing epidural catheters for urgent cesarean delivery3. It was found that the chloroprocaine group had a significantly faster onset of anesthesia compared to the lidocaine group. Both drugs provided excellent anesthesia. However a high quality study comparing 3% chloroprocaine with 2% lidocaine/ epinephrine/ bicarbonate/ fentanyl (LEBF) in terms of anesthetic onset times has yet to be performed. Women in labor frequently request an epidural to provide pain relief. Epidural pain relief is commonly provided by the administration of a low concentration of local anesthetic and opioid solution through an epidural catheter. This solution is delivered by an automated epidural infusion pump. In the event that a cesarean delivery is required, the pre-existing epidural is frequently used to administer a higher concentration anesthetic solution to allow pain free cesarean delivery. This is commonly referred to as an epidural top up or as an extension of the epidural block. Standard practice at University of Arkansas for Medical Sciences (UAMS) for an epidural top up is Lidocaine, Epinephrine, Bicarbonate and Fentanyl (LEBF) or 3% chloroprocaine. These two mixtures are routinely and almost exclusively used for epidural cesarean delivery. The decision on which mixture to use is based solely on physician preference. It is likely that the LBEF mixture is used more frequently but the investigators consider both local anesthetic mixtures as equals and the standard of care at UAMS. The investigators do not use any other local anesthetics (unless there are very specific reasons).
Interventions
2% Lidocaine using a combined spinal-epidural (CSE)
3% Chloroprocaine using a combined spinal-epidural (CSE)
Sponsors
Study design
Eligibility
Inclusion criteria
* ≥ 18 years of age for the mother * Singleton pregnancy * Gestation \> 36 weeks * American Society of Anesthesiologist (ASA) class II * Provides written consent * Infant of mother
Exclusion criteria
* Patient refusal * Non-elective or urgent/emergent cesarean sections * ASA class III or above * Unable to understand English * Significant back surgery or scoliosis * Known fetal abnormality * Weight \> 120 kg * Height \< 150 cm * Allergy to local anesthetics * Concurrent use of sulfonamides
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The Onset Time to Surgical Anesthesia | Up to 35 minutes | The onset time to surgical anesthesia, as reported by the participant using a standard procedure This will be measured by the time taken from the end of the epidural loading dose to develop a loss of touch sensation using a neurotip® (Owen Mumford, USA) device bilaterally at the T7 dermatomal level using a non-inferiority study design. A non-inferiority limit of 3 minutes was chosen apriori. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Secondary Outcome: Number of Participants With Requirement for Intraoperative Analgesia Supplementation | 1 hour | This requirement for any rescue medications to control discomfort or pain during CD |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| 2% Lidocaine 2% Lidocaine: 2% Lidocaine (with epinephrine, bicarbonate, and fentanyl) using a combined spinal-epidural (CSE) | 34 |
| 3% Chloroprocaine 3% Chloroprocaine: 3% Chloroprocaine using a combined spinal-epidural (CSE) | 33 |
| Total | 67 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lack of Efficacy | 1 | 1 |
| Overall Study | Protocol Violation | 0 | 1 |
Baseline characteristics
| Characteristic | Total | 3% Chloroprocaine | 2% Lidocaine |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 67 Participants | 33 Participants | 34 Participants |
| Age, Continuous | 28 years | 30 years | 27 years |
| BMI | 31 kg/m^2 | 32 kg/m^2 | 31 kg/m^2 |
| Duration of epidural infusion | 49 minutes | 49 minutes | 48 minutes |
| Gestational age | 273 days | 273 days | 273 days |
| Race/Ethnicity, Customized African American | 25 participants | 12 participants | 13 participants |
| Race/Ethnicity, Customized Other | 42 participants | 21 participants | 21 participants |
| Region of Enrollment United States | 67 participants | 33 participants | 34 participants |
| Sex: Female, Male Female | 67 Participants | 33 Participants | 34 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 34 | 0 / 33 |
| other Total, other adverse events | 0 / 34 | 1 / 33 |
| serious Total, serious adverse events | 0 / 34 | 0 / 33 |
Outcome results
The Onset Time to Surgical Anesthesia
The onset time to surgical anesthesia, as reported by the participant using a standard procedure This will be measured by the time taken from the end of the epidural loading dose to develop a loss of touch sensation using a neurotip® (Owen Mumford, USA) device bilaterally at the T7 dermatomal level using a non-inferiority study design. A non-inferiority limit of 3 minutes was chosen apriori.
Time frame: Up to 35 minutes
Population: Per protocol analysis
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 2% Lidocaine | The Onset Time to Surgical Anesthesia | 558 seconds | Standard Deviation 269 |
| 3% Chloroprocaine | The Onset Time to Surgical Anesthesia | 655 seconds | Standard Deviation 258 |
Secondary Outcome: Number of Participants With Requirement for Intraoperative Analgesia Supplementation
This requirement for any rescue medications to control discomfort or pain during CD
Time frame: 1 hour
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| 2% Lidocaine | Secondary Outcome: Number of Participants With Requirement for Intraoperative Analgesia Supplementation | 4 Participants |
| 3% Chloroprocaine | Secondary Outcome: Number of Participants With Requirement for Intraoperative Analgesia Supplementation | 7 Participants |