ED90 of 3% Chloroprocaine for Cervical Cerclage

Study Overview
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Brief Summary
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The aim of this study is to identify the dose of intrathecal (IT) chloroprocaine that provides effective anesthesia in 90% of patients undergoing elective cerclage placement (intraoperative analgesic supplementation not required).

Detailed Description
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Cervical cerclage is a procedure performed on pregnant women with cervical incompetence to reduce the risk of second trimester spontaneous abortion and preterm labor. This outpatient procedure is performed commonly under both general and regional anesthesia. In an effort to ensure rapid discharge some institutions prefer the use of general anesthesia; however, this has the disadvantage of exposing the fetus to general anesthetic drugs, increased risk of aspiration and a higher requirement for opioid analgesia post operatively. The benefits of neuraxial anesthesia for cerclage placement includes rapid onset of a dense sensory block, reduced fetus exposure to medications, and maintenance of maternal airway reflexes. Successful analgesia for cerclage placement requires a sensory block from S4-T10 dermatomes. Inadequate sensory coverage with a spinal anesthetic typically necessitates the conversion to general anesthesia adding risk to the mother and fetus while increasing intraoperative times and resources. Currently there are no studies determining optimum dose of spinal chloroprocaine for cervical cerclage. The investigators propose a dose determining study to determine the ED90 of intrathecal lidocaine and chloroprocaine which will help decrease incidence of inadequate anesthesia for cervical cerclage. This is a multicenter, double blinded, dose ranging, biased-coin design study. Usual practice for regional anesthesia for cerclage placement consists of a mixture of 3% chloroprocaine and fentanyl. The exact dosing of the local anesthetic mixture used is dependent on the anesthesiologist's preference. Chloroprocaine provides a rapid onset of surgical anesthesia with little need for intraoperative analgesic supplementation. If there are contraindications for spinal anesthesia or patient refusal than general anesthesia is offered as an alternative. The aim of this study is to assess the anesthetic quality of various doses chloroprocaine and in elective cerclage placement. Chloroprocaine is licensed and commonly administered intrathecally for cerclage placement. To mitigate against the occurrence of inadequate analgesia in this ED90 study, a combined spinal-epidural technique will be utilized in order to provide supplemental analgesia via epidural top up if needed. The investigators propose testing the hypothesis in patients scheduled for elective cervical cerclage placement. Participants will receive standard of care for anesthesia but in the context of a clinical trial with the addition of randomization, blinding, and more comprehensive evaluation of the trial outcomes (see outcomes objectives below). The proposed study will be conducted over a 2 year period from January 2019 to September 2020. Spinal Study Solutions The solutions and their administration procedures are identical to those used outside this research and are almost exclusively used for patients requiring spinal anesthesia for cervical cerclage. The only deviation involves diluting the chloroprocaine with saline so that study solutions are of equal volume to maintain blinding. Initial Patient (A#X) 45mg (1.5mL) of Chloroprocaine 3% (Nesacaine - Fresenius Kabi), will be drawn up into a 3 ml syringe (a 1 ml 'TB syringe' will be used to aspirate the drug in aliquots to ensure accuracy). The following additive will be added: 10 mcg (0.2ml) of fentanyl (50 mcg/ml) 0.3 ml of sterile 0.9% sodium chloride Thus the total volume in the syringe will be 2 ml. Study drugs will be prepared by one anesthesiologist (un-blinded) and administered by another anesthesiologist (blinded). Subsequent Patient (A#X+1) The dose of Chloroprocaine 3% based on outcome from prior subject and calculations mentioned previously will be added to 10 mcg (0.2ml) of fentanyl (50 mcg/ml). Sterile 0.9% sodium chloride will be added until the total volume in the syringe is 2 ml. Rescue If the subject has discomfort and requests analgesia, then 5 ml of 3% chloroprocaine via the epidural route will be given, alternatively the anesthesiologist can treat the discomfort at his discretion. Other alternatives include intravenous fentanyl, ketamine, inhalational nitrous oxide and conversion to general anesthesia. Riks/Benefit Risks of the procedure include the following: discomfort during placement (10% or 1 in 10), drop in blood pressure (1% or 1 in 100), headache (1% or 1 in 100), allergic reactions (0.001% or 1 in 100,000), bleeding or infection (0.001% or 1 in 100,000), damage to nerves (0.001% or 1 in 100,000), failure of the anesthetic or inadequate anesthesia and need for general anesthesia (0.1% or 1 in 1,000). The benefit of participating in the study is that perceived pain may be better controlled, however this cannot be guaranteed. This study will be conducted at two study sites, the University of Arkansas for Medical Sciences in Little Rock, Arkansas and Duke University in Durham, North Carolina.

Official Title
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Determining the ED90 for Intrathecal 3% Chloroprocaine for Elective Cervical Cerclage Surgery

Conditions
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Cerclage, Cervical

Intervention / Treatment
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* Drug: Chloroprocaine Hcl 3% Inj


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ≥ 18 years of age Singleton pregnancy ASA class II or III Cervical cerclage 1st or 2nd trimester of pregnancy Simple prophylactic cervical cerclage Exclusion Criteria: Patient refusal Abdominal and complex cervical cerclage (e.g. bulging bag) BMI ≥ 50 kg/m2 ASA class IV or above Contraindication to neuraxial anesthesia Allergy to chloroprocaine

Ages Eligible for Study
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Minimum Age: 18 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: Diagnostic
Intervention Model: Sequential Assignment
Interventional Model Description: Initial Patient (A#X) 45mg (1.5mL) of Chloroprocaine 3% (Nesacaine - Fresenius Kabi), will be drawn up into a 3 ml syringe (a 1 ml 'TB syringe' will be used to aspirate the drug in aliquots to ensure accuracy). The following additive will be added: 10 mcg (0.2ml) of fentanyl (50 mcg/ml) 0.3 ml of sterile 0.9% sodium chloride Thus the total volume in the syringe will be 2 ml. Study drugs will be prepared by one anesthesiologist (un-blinded) and administered by another anesthesiologist (blinded). Subsequent Patient (A#X+1) The dose of Chloroprocaine 3% based on outcome from prior subject and calculations mentioned previously will be added to 10 mcg (0.2ml) of fentanyl (50 mcg/ml). Sterile 0.9% sodium chloride will be added until the total volume in the syringe is 2 ml.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Chloroprocaine dose<br>Initial Patient (A#X) 45mg (1.5mL) of Chloroprocaine 3% (Nesacaine - Fresenius Kabi), will be drawn up into a 3 ml syringe (a 1 ml 'TB syringe' will be used to aspirate the drug in aliquots to ensure accuracy). The following additive will be added: 10 mcg (0.2ml) of fentanyl (50 mcg/ml) 0.3 ml of sterile 0.9% sodium chloride Thus the total volume in the syringe will be 2 ml. Study drugs will be prepared by one anesthesiologist (un-blinded) and administered by another anesthesiologist (blinded). Subsequent Patient (A#X+1) The dose of Chloroprocaine 3% based on outcome from prior subject and calculations mentioned previously will be added to 10 mcg (0.2ml) of fentanyl (50 mcg/ml). Sterile 0.9% sodium chloride will be added until the total volume in the syringe is 2 ml. | Drug: Chloroprocaine Hcl 3% Inj<br>* Initial Patient (A#X) 45mg (1.5mL) of Chloroprocaine 3% (Nesacaine - Fresenius Kabi), will be drawn up into a 3 ml syringe (a 1 ml 'TB syringe' will be used to aspirate the drug in aliquots to ensure accuracy). The following additive will be added: 10 mcg (0.2ml) of fentanyl (50 mcg/ml) 0.3 ml of sterile 0.9% sodium chloride Thus the total volume in the syringe will be 2 ml. Study drugs will be prepared by one anesthesiologist (un-blinded) and administered by another anesthesiologist (blinded). Subsequent Patient (A#X+1) The dose of Chloroprocaine 3% based on outcome from prior subject and calculations mentioned previously will be added to 10 mcg (0.2ml) of fentanyl (50 mcg/ml). Sterile 0.9% sodium chloride will be added until the total volume in the syringe is 2 ml.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Dose of Intrathecal (IT) Chloroprocaine That Provides Effective Anesthesia in 90% of Patients Undergoing Elective Cerclage Placement (Intraoperative Analgesic Supplementation Not Required). | Identification of the dose of intrathecal 3% chloroprocaine that will provide adequate anesthesia for a cervical cerclage to occur. | 60 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum Pain Numerical Pain Rating Scale (NPRS) During Surgery (as Reported by Patient, Scored From 0-10 in the PACU). | The scale from 0-10 is used where a score of 0 represents no pain at all and a score of 10 represents the worst pain a participant could imagine. It is reported as a single score at a single point in time. No subscales are used. | 60 minutes | 
| Number of Participants Who Reported Nausea (Self-reported by Patient, Yes or no). | Number of participants reporting nausea. | 60 minutes | 
| Number of Participants With Observed Vomiting. (Observed Yes or no). | Number of participants with observed vomiting. | 60 minutes | 
| Number of Participants Reporting Itching. (Self-reported by Patient, Yes or no). | Number of participants reporting itching. | 60 minutes | 
| Number of Patients Who Were Given Vasopressor Phenylephrine (and Ephedrine) BP Drops Greater Than 15% Below Baseline or < 100mg Hg Systolic. |  | 60 minutes | 
| The Average Dose of Phenylephrine Given to Those Patients Whose BP Dropped Greater Than 15% Below Baseline or < 100mg Hg Systolic. | All patients were analyzed for possible requirement of this intervention, though all participants did not require the intervention. | 60 minutes | 
| Overall Patient Satisfaction at Time of PACU Discharge. | The scale used is 0-10 where 0 would represent completely unsatisfied and 10 would be completely satisfied. A 10 would imply that if a participant had to have the procedure performed again, it would be repeated in the exact same fashion it was carried out the first time. This will be assessed at the time of PACU discharge and will be asked one time. No subscales are used. | 60 minutes | 
| Time to Resolution of Motor Block at End of the Cerclage Placement (Measured in the PACU). | The motor block is assessed using the Bromage scale (1-5). The block is objectively assessed using this scale based on which joints a patient is able to mobilize following epidural or subarachnoid block. A score of 1 represents a patient who is unable to mobilize any lower extremity joint. A score of 5 represents a patient able to mobilize all lower extremity joints. | 60 minutes | 
| Time to Hospital Discharge as Measured as the Time Difference Between Local Anesthetic Injection and Discharge Time as Recorded in the Medical Notes |  | approximately 180 minutes | 
| Time From Spinal Block to Ambulation |  | up to 180 minutes | 
| Time From Spinal Block to Micturition |  | approximately 180 minutes | 
| Time to Complete Sensory Regression |  | up to 180 minutes | 
| Time to Resolution of Motor Block (Bromage Score of 5) | The motor block is assessed using the Bromage scale (1-5). The block is objectively assessed using this scale based on which joints a patient is able to mobilize following epidural or subarachnoid block. A score of 1 represents a patient who is unable to mobilize any lower extremity joint. A score of 5 represents a patient able to mobilize all lower extremity joints. | up to 180 minutes | 
| Time to Readiness for PACU Discharge (Pre-defined Nursing Criteria) | Readiness for PACU discharge would include a patient who is able to ambulate unassisted (indicating resolution of motor block), has vital signs within normal limits, has pain levels acceptable to the patient, and has been able to urinate. | approximately 180 minutes |