Pain, Pregnancy, Surgery
Conditions
Keywords
Pain, Surgery, Pregnancy, Anesthesia
Brief summary
Cervical incompetence complicates approximately 1 in 500 pregnancies . Those women with cervical incompetence are at risk for second trimester spontaneous abortion and preterm labor. Cervical cerclage reduces these risks but must be performed under general or neuraxial anesthesia. Some anesthesiologists prefer neuraxial anesthesia, as it reduces fetal exposure to medications and avoids the risks associated with loss of maternal airway reflexes under general anesthesia. Spinal anesthesia, in particular, has the added advantage of being technically simple while still providing a rapid, dense sensory block. For cerclage placement, patients require a sensory block from the T10 to S4 dermatome in order to cover sensation from the cervix as well as the vagina and perineum. Patients presenting for cerclage under spinal anesthesia pose a dosing challenge given the physiologic changes associated with pregnancy. As women progress with their pregnancy, they require lower doses of intrathecal local anesthetic to achieve similar block level. Multiple studies have demonstrated that these changes start during the second trimester. Inadequate sensory coverage with a spinal anesthetic typically necessitates conversion to general anesthesia, causing additional time wasted and added risk to the patient and fetus. Anecdotally, this is the reason why some anesthesiologists choose general anesthesia for patients undergoing cerclage over a spinal anesthetic. As there is currently no literature determining the correct dosage for these patients, we propose a dose-response study to determine the ED90 of intrathecal lidocaine for adequate anesthesia for elective cervical cerclage placement.The findings of this study will help determine the minimum dose of intrathecal lidocaine necessary to provide adequate spinal anesthesia for cervical cerclage for 90% of women. This will help decrease the frequency of inadequate anesthesia for cervical cerclage.
Interventions
DRUGLidocaine Administration
The lidocaine dose will be determined using a 9:1 biased-coin sequential allocation method. For the first participant, the starting dose will be 32 mg of 2% isobaric lidocaine (1.6 mL). Two outcomes will be possible: satisfactory or unsatisfactory anesthesia.
Sponsors
Northwestern University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Any patient who is at least 18 years old * ASA physical class I or II * BMI \<40 kg/m2, * Presents for elective cervical cerclage during their first or second trimester of pregnancy will be eligible to participate.
Exclusion criteria
* Any patient who is not a candidate for neuraxial anesthesia (including coagulopathy, * Local skin infection, uncorrected hypovolemia) * Allergy to lidocaine or fentanyl * Chronic opioid user * History of failed neuraxial anesthesia or analgesia, * Had prior spine surgery * Can not assume a sitting position for spinal anesthesia due to risk of amniotic membrane rupture
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time to T 10 Level | 20 minutes after drug administration | Elapsed time in minutes to achieve T 10 level of anesthesia. Assessed by the anesthesia care provider using crushed ice. T 10 level is numbness up to the level of the belly button. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Spinal Lidocaine Administration Spinal anesthesia will be induced with isobaric 2% lidocaine and 15 μg fentanyl.
The study lidocaine dose will be determined using a 9:1 biased-coin sequential allocation method. For the first participant, the starting dose will be 32 mg of 2% isobaric lidocaine (1.6 mL). If the lidocaine dose provides an unsatisfactory anesthetic, the case will be categorized as a failure. After a failed case, the next participant will receive a lidocaine dose increased by 4 mg. If the lidocaine dose provides satisfactory anesthesia, the next participant's lidocaine dose will determined by a biased allocation method with a 90% chance of maintaining the dose and a 10% chance of decreasing the dose by 4 mg.
Lidocaine Administration: The lidocaine dose will be determined using a 9:1 biased-coin sequential allocation method. For the first participant, the starting dose will be 32 mg of 2% isobaric lidocaine (1.6 mL). Two outcomes will be possible: satisfactory or unsatisfactory anesthesia. | 2 |
| Total | 2 |
Baseline characteristics
| Characteristic | Spinal Lidocaine Administration |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 2 Participants |
| Age, Continuous | 34 Years |
| Baseline diastolic blood pressure | 60 millimeters of mercury |
| Baseline heart rate | 73 Beats per minute |
| Baseline systolic blood pressure | 111.5 millimeters of mercury |
| Estimated Gestational Age | 13.3 weeks |
| Height | 163.5 centimeters |
| Indication for cerclage Cervical Incompetence | 1 Participants |
| Indication for cerclage History of previous loss | 1 Participants |
| Number of live births | 1 Number of live births |
| Number of times pregnant | 4 Number of pregnancies |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 2 Participants |
| Region of Enrollment United States | 2 count of participants |
| Sex: Female, Male Female | 2 Participants |
| Sex: Female, Male Male | 0 Participants |
| Weight | 54.1 Kilograms |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 2 |
| other Total, other adverse events | 0 / 2 |
| serious Total, serious adverse events | 0 / 2 |
Outcome results
Primary
Time to T 10 Level
Elapsed time in minutes to achieve T 10 level of anesthesia. Assessed by the anesthesia care provider using crushed ice. T 10 level is numbness up to the level of the belly button.
Time frame: 20 minutes after drug administration
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Spinal Lidocaine Administration | Time to T 10 Level | 12.5 Minutes |