12 Versus 20 mL Paracervical Block for Pain-Control During Cervical Preparation for Dilation and Evacuation: A Single-Blinded Randomized Controlled Trial
Phase: PHASE4
Conditions: Pain
Sponsor: Stanford University

NCT03356145 
 
July 24, 2018 
 
 
 
 
 
 
 
 
 
 
 
 
 
12 vs. 20 mL paracervical block for pain-control during cervical preparation for dilation and 
evacuation: A single-blinded randomized controlled trial  
 
 
, MPH 
, MD 
, MD, MS 
, MD, MPH 
Stanford University  
 
 
 
 
 
Phone: 
 
Email: 
 
 
 

Project Summary 
 
Description of the Project 
 
1.1 Rationale and objectives of the study 
 
1.1.1 Rationale 
 
Paracervical block (PCB) is a widely used, but largely unstandardized technique for pain 
management in gynecological procedures. From hysteroscopy to first trimester abortion 
procedures to dilator placement for dilation and evacuation,  providers utilize the paracervical 
block to manage cervical dilation pain. However for such a widely used technique, the exact 
method is often provider or site specific. A 2009 survey of National Abortion Federation 
members i illustrates that the volume alone of anesthestic used for PCB in first trimester abortion 
procedures varies tremendously amongst providers. That said, research published over the last 
few years has had enormous impact on global guidelines, such as those published by Ipas. New 
techniques for paracervical block that focus on limiting symptoms and resources while also 
ensuring adequate pain management are needed to improve care for women around the world.  
 
A randomized controlled trial done by Renner et al. in 2012ii demonstrated that a 4-site, 18 mL 
1% lidocaine paracervical block, with a 2 mL injection for tenaculum placement, used during 
first-trimester surgical abortions was beneficial in reducing pain due to cervical dilation when 
compared to sham paracervical block. The block technique endorsed by Renner et al. was based 
on findings from a combination of studies about paracervical block that investigated variations in 
needle injection siteiii, type of lidocaineiv, depth of lidocaine injectionv, general vs. local 
anesthesiavi, and wait time between injection and procedurevii. Missing from consideration, 
however, was the volume of lidocaine necessary to achieve a reduction in dilation pain. The final 
technique used in Renner et al.’s study was as follows: 
 
• Syringe loaded with 18 mL of 1% plain lidocaine buffered with 2 mL 8.4% sodium 
bicarbonate (20 mL total); 20-gauge spinal needle 
• 2 mL injected at the tenaculum site, 12 o’clock superficially into the cervix 
• The tenaculum is immediately placed at 12 o’clock 
• The remaining 18 mL are injected slowly over 60 seconds into the cervicovaginal 
junction in four equal aliquots at 2, 4, 8, and 10 o’clock; the injection is continuous from 
superficial to deep (3 cm) to superficial (injecting with insertion and withdrawal) 
• Dilation begins 3 minutes after application of the block 
 
A subsequent study done by Renner et al. in 2016viii aimed to further refine this technique and 
looked at both the 3-minute wait time and the use of 4-site versus 2-site injection. Results of the 
study were largely inconclusive, suggesting that no wait time is no worse than a three-minute 
wait and that 2-site and 4-site injections may be interchangeable. Despite these findings, global 
guidelines and provider preference continue to follow findings from Renner et al.’s 2012 study. 
 
As the dangers of lidocaine injection are minimal, but not absent, and the administration of a 
paracervical block is painful and time-consuming, we propose comparing a technique similar to 

the one put forth by Renner et al. with one that has been used in multiple Stanford studies and 
notably employs a smaller volume of lidocaine and only two injection sites. The technique is as 
follows: 
 
• Syringe loaded with 12 mL of 1% lidocaine (120 mg); 22-gauge spinal needle  
• 2 mL injected at the tenaculum site, either 6 or 12 o’clock superficially into the cervix 
• The tenaculum is immediately placed at the previously injected site 
• The remaining 10 mL are slowly injected into the cervicovaginal junction in two equal 
aliquots at 4 and 8 o’clock; the injection is continuous from superficial to deep (3 cm) to 
superficial (injecting with insertion and withdrawal) 
• No wait time between injection and dilator insertion 
 
We aim to compare this technique with one similar to Renner et al.’s technique from 2016: 
• Syringe loaded with 20 mL of 1% lidocaine (120 mg); 22-gauge spinal needle  
• 2 mL injected at the tenaculum site, either 6 or 12 o’clock superficially into the cervix 
• The tenaculum is immediately placed at the previously injected site 
• The remaining 18 mL are slowly injected into the cervicovaginal junction in two equal 
aliquots at 4 and 8 o’clock; the injection is continuous from superficial to deep (3 cm) to 
superficial (injecting with insertion and withdrawal) 
• No wait time between injection and dilator insertion 
 
Our justification for this proposed technique comparison is as follows:  
 
With regards to smaller dosage, there is much research to be done. While the lidocaine label 
recommends a maximum dose of 200 mg (20 mL at 1%) of lidocaine per 90-minute period for 
paracervical block,ix it does not recommend a minimum dose. Renner et al.’s 2012 studyii 
provides evidence for paracervical block over sham for cervical dilation pain and Chanrachakul’s 
2001 studyx provides evidence that pain relief comes from both lidocaine and distention rather 
than distention alone. These studies point to the benefit of using lidocaine, but to date there is 
little data providing the optimal dose between 0 mL and 20 mL. With this knowledge, we 
propose the use of 10 mL of lidocaine in order to maintain the use of lidocaine for pain control, 
but minimize symptoms (such as metallic taste, ringing in the ears, and at worst, seizure or 
cardiac arrest) that are more likely to manifest with 20 mL.  
 
With regards to 2-site versus 4-site, our aim is to build on the findings from Glantz and 
Shomento’s 2001 study and Renner et al.’s 2016 study. Glantz and Shomento’s study from 
2001iii contained four study arms and looked at both 1% chloroprocaine versus placebo and 4-
site versus 2-site injection. While the original paper concluded that PCB with chloroprocaine 
provides more pain relief than saline for both 4-site and 2-site injections, subsequent reanalysis 
from 2009xi showcased that preference for 4-site or 2-site versus saline depended on the time 
point at which pain was measured. Regardless, more importantly, the findings showed that when 
comparing 4-site 1% chloroprocaine block to 2-site 1% chloroprocaine block, there is no 
statistical difference. Furthermore, Renner et al.’s 2016 studyviii, which compared 20 mL of 1% 
buffered lidocaine at 4-site versus 2-site, showcased that using noninferiority analysis, there is no 
statistical difference between 4-site and 2-site block. Additionally, while superiority analysis 
demonstrated that 4-site is stastically superior to 2-site for pain control at cervical dilation, this 

demonstrated difference is not clinically significant. All in all, these data point toward the 
clinical conclusion that 2-site may be utilized in place of 4-site. Our proposed technique follow 
findings from these studies and if proven effective, would result in fewer painful injections 
during paracervical block.  
 
Concerning depth of injection, we will utilize the 3 cm depth as used in Renner’s studies. Wiebe 
et al.’s 1992 studyiv and Cetin and Cetin’s 1997 studyv suggest utilizing deep injection, as 
dilation pain scores were lower for deep injection in both studies.  
 
Phair et al.’s 2002 studyxii and Renner et al.’s 2016 studyviii both showcased that there is no 
significant difference in pain with cervical dilation when comparing no-wait between PCB 
injection and cervical dilation to wait. As such, we have opted to exclude a wait time.  
 
With regard to plain lidocaine versus buffered lidocaine, while several studies have showcased 
the benefit of utilizing buffered lidocaine instead of plain lidocaineiv, given the high cost and 
prolonged preparation time associated with creation of a buffered lidocaine solution, we have 
decided to use 1% plain lidocaine. Our hope is that by showcasing pain control with a more cost-
effective anesthetic, our results will be generalizable to a larger global audience.  
 
Finally, while many studies focus on pain control in first-trimester abortion, including Renner et 
al., in order to isolate cervical dilation pain from uterine pain, we have chosen to focus on the 
cervical preparation procedure needed prior to a second trimester surgical abortion rather than 
the surgical procedure itself. Need for additional research in this timeframe was highlighted in 
Soon et al.’sxiii work, which demonstrated that the paracervical block technique utilized by 
Renner et al. was effective in reducing pain associated with osmotic dilator insertion prior to 
second trimester abortion. We also believe that isolating the pain of the cervical dilation 
procedure will allow us to generalize the findings of our study to be meaningful for any 
procedure in which cervical dilation is necessary.  
 
 
1.1.2 Objectives and hypothesis 
 
We hypothesize that a 2-site, 12 mL 1% plain lidocaine injection paracervical block (PCB) 
technique (2 mL for tenaculum placement, 10 mL for paracervical block) will provide non-
inferior pain control compared to a previously established 2-site, 20 mL 1% lidocaine injection 
PCB (2 mL for tenaculum placement, 18 mL for paracervical block) when administered for 
dilation pain control during cervical preparation. 
 
Our primary objective is to determine pain perceived at time of dilator insertion measured by 
Visual Analogue Scale (VAS; Dilator Insertion: Immediately following dilator insertion) (0-
100mm).  
 
Secondary objectives include assessing: 
- 
Pain perceived at additional time points before, during, and after the procedure (all 
measured by VAS (0-100mm; 0 being no pain and 100 being worst pain imaginable): 
o Anticipated Pain: 30 minutes prior to procedure 

o Baseline Pain: Immediately prior to procedure 
o Block injection Pain: Immediately following injection, but prior to dilator 
insertion 
o Post-procedure Pain: 10-15 minutes following procedure 
o Overall Pain: Assessed after procedure (prior to discharge) 
- 
Total procedure time, as defined by speculum time 
- 
Incidence of complications 
o Inability to dilate cervix 
o Seizure 
o Cardiac arrest 
o Structural trauma (uterine perforation, cervical laceration, etc.)  
o Hemorrage (EBL estimation)  
- 
Symptom Data 
o Following block injection, any experience of: 
 Metallic taste in mouth 
 Ringing in ears 
 Lightheadedness 
- 
Any other systemic symptoms experienced, including vasovagal reaction 
- 
Provider reported ease of insertion 
- 
Global satisfaction (acceptability) of procedure reported by participant (VAS, 0-100mm; 
0 being unsatisfied and 100 being fully satisfied) 
 
1.2 Design and methodology 
 
1.2.1 Research design and General Methodological Approach 
 
This is a non-inferiority, single blinded, randomized controlled trial.  
 
1.2.2 Criteria for the selection of subjects 
 
Women who need dilator placement for second trimester D&E procedures will be invited to 
participate in the study protocol. This population was chosen because our aim is to isolate how 
best to manage cervical dilation pain and not uterine aspiration pain, which is potentially a 
confounding factor when analyzing pain perceived during first trimester abortions rather than 
cervical dilation procedures alone. Additionally, we will limit our study population to those 
women presenting for an abortion ≥16 weeks gestation. This population was selected as they 
typically require more dilators than the patients at lower gestational ages.  
 
Specific inclusion criteria: 
• Women 18 and older 
• Intrauterine pregnancy ≥16 weeks gestation  
• English speaking competency 
• Willing and able to sign consent forms 
• Agree to comply with study procedures  
 
1.2.3 Subject recruitment and allocation 

 
Subjects will be recruited from Stanford Gynecology Clinic in Palo Alto, California and at 
Planned Parenthood Mar Monte in San Jose, CA. 
• At Stanford, potential participants will be identified by prospective chart review done by 
clinical research coordinators. Once identified, clinical research coordinators will obtain 
permission from provider to speak with participants.  
• At Planned Parenthood, clinic staff will notify clinical research coordinators of potential 
participants.  
 
To ensure even allocation across sites, two randomization schemes will be created, one for each 
site.  
 
1.2.4 Description of the drugs and devices to be studied 
 
Xylocaine (lidocaine HCl) is a common local anesthetic that works by stabilizing the neuronal 
membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses. 
Local anesthetics of the amide type are thought to act within the sodium channels of the nerve 
membrane. According to the packaging insert, anesthesia is achieved within 5 minutes, 
depending on the area of application, and duration of anesthesia is approximately 20-30 minutes.  
 
For paracervical block the drug label recommends a maximum dose of 200 mg (100 mg per side) 
in a 90 minute periodix. Given risk of rapid systemic absorption and possible maternal seizure 
and cardiovascular collapse, the maximum dose should not be exceeded. The label also 
recommends slow injection and a 5-minute interval between each side.  
 
Contraindications to lidocaine include the following: 
• Hypersensitivity to lidocaine or any component of the formulation 
• Hypersensitivity to another local anesthetic of the amide type 
• Adam-Stokes syndrome 
• Wolff-Parkinson-White syndrome 
• Severe degrees of SA, AV, or intraventricular heart block (except in patients with a 
functioning artificial pacemaker) 
• Premixed injection may contain corn-derived dextrose and its use is contraindicated in 
patients with allergy to corn or corn-related products 
 
1.2.5 Admission procedure 
 
Eligible women will be screened and identified in two ways. The first will be via prospective 
chart review done by Stanford clinical research personnel. The second will be providers and 
clinic staff informing clinical research personnel of potential participants.  
 
If potential participants meet inclusion criteria and permission has been granted by their 
provider, they will be approached by a clinical research coordinator who will review the study 
protocol and obtain informed consent. After obtaining informed consent, participants will be 
randomized to a study arm via computer-generated block randomization using REDCap 

software. The provider and staff will be aware of arm allocation, but participants will remain 
blinded.  
 
There will be two study arms: 
 
Experimental:  
• Syringe loaded with 12 mL of 1% lidocaine (120 mg); 22-gauge spinal needle  
• 2 mL injected at the tenaculum site, either 6 or 12 o’clock superficially into the cervix 
• The tenaculum is immediately placed at the previously injected site 
• The remaining 10 mL are slowly injected into the cervicovaginal junction in two equal 
aliquots at 4 and 8 o’clock; the injection is continuous from superficial to deep (3 cm) to 
superficial (injecting with insertion and withdrawal) 
• No wait time between injection and dilator insertion 
 
Control: 
• Syringe loaded with 20 mL of 1% lidocaine (120 mg); 22-gauge spinal needle  
• 2 mL injected at the tenaculum site, either 6 or 12 o’clock superficially into the cervix 
• The tenaculum is immediately placed at the previously injected site 
• The remaining 18 mL are slowly injected into the cervicovaginal junction in two equal 
aliquots at 4 and 8 o’clock; the injection is continuous from superficial to deep (3 cm) to 
superficial (injecting with insertion and withdrawal) 
• No wait time between injection and dilator insertion  
 
Prior to the procedure, clinical research coordinators will obtain the following baseline 
information using REDCap: 
• Demographics 
o Location of procedure 
o MRN 
o Date enrolled 
o First name 
o Last name 
o Date of birth 
o Age 
o Phone number 
o Race 
o Ethnicity 
• Medical History (Physical Exam and Ob/Gyn History) 
o Height 
o Weight 
o BMI 
o First day of lest menstrual period 
o Gestational age defined by U/S 
o Medication allergies 
o Current medications 
o Number of previous pregnancies 
 Number of previous vaginal deliveries 

 Number of previous cesarean sections 
 Number of previous abortions 
 Number of previous abortions after 16 weeks gestation 
 Number of miscarriages  
o Recent deliveries 
o Medical problems 
o Previous surgeries  
 Previous cervical surgeries 
 Other previous surgeries 
 
The participant will then be prepped for the procedure. At that point, the clinical research 
coordinator will accompany participants throughout the duration of their procedure and obtain 
the following information: 
 
• Procedure Data 
o Provider type (i.e. resident, fellow, attending) 
o Provider reported ease of procedure 
o Initial cervical dilation 
o Uterine position 
o Number of osmotic dilators placed 
o Total procedure time, as defined by speculum time 
o Digoxin given 
o Complications 
 Inability to dilate cervix 
 Seizure 
 Cardiac arrest 
 Structural trauma (uterine perforation, cervical laceration, etc.)  
 Hemorrage (EBL estimation)  
o Administration of Mifepristone for cervical preparation 
• Procedure VAS Data 
o Anticipated Pain: 30 minutes prior to procedure 
o Baseline Pain: Immediately prior to procedure 
o Block injection Pain: Immediately following injection, but prior to dilator 
insertion 
o Dilator Insertion Pain: Immediately following dilator insertion 
o Post-procedure Pain: 10-15 minutes following procedure 
o Overall Pain: Assessed after procedure (prior to discharge) 
• Symptom Data 
o Following block injection, any experience of: 
 Metallic taste in mouth 
 Ringing in ears 
 Lightheadedness 
o Any other systemic symptoms experienced, including vasovagal reaction 
• Acceptability Data 
o Global sastisfaction with procedure 
• Recognition of group allocation 

 
1.2.6 Follow-up procedure 
 
No follow-up required.  
 
1.2.7 Criteria for discontinuation 
 
Participants requiring additional cervical anesthesia or intervention due to complication during 
the dilation procedure will be discontinued from the study.  
 
1.2.8 Laboratory and other investigations 
 
Not applicable.  
 
1.2.9 Data management 
 
Data will be collected on REDCap software, and will be coded, monitored and verified.  
 
1.2.10 Data analysis 
 
Perioperative characteristics will be examined among the groups using chi square test and 
fisher’s exact test, where appropriate; mean and median VAS pain scores will be analyzed with 
Student’s t-tests and non-parametric tests, respectively; mean and median overall satisfaction 
with pain control and provider reported ease of procedure via VAS scores will be compared 
using Student’s t-tests and non-parametric tests, respectively; linear regression will be completed 
in multivariable analysis to identify predictors of pain. Complications and patient symptoms 
associated with lidocaine toxicitiy will be examined between the groups using chi square test and 
fisher’s exact test, where appropriate. 
 
1.2.11 Number of subjects and statistical power 
 
88 participants are required to be 80% sure that the lower limit of a one-sided 97.5% confidence 
interval (or equivalently a 95% two-sided confidence interval) will be less than the non-
inferiority limit of 15mm. Accounting for participant drop-out, we will recruit 96 women to 
participate in this study (significance level, alpha of 5%; power of 80%; standard deviation of 28; 
non-inferiority limit of 15).  
 
1.2.12 Study limitations 
 
The major limitation of this study is the inability to blind providers. Given the need to give 
different volumes of lidocaine, blinding is not possible.  
 
1.2.13 Duration of project 
 

Given that recruitment will take place at both Stanford and Planned Parenthood, we will assume 
a conservative recruitment rate of 11 participants per month which will require approximately 9 
months.  
 
1.3 Project management 
 
Project management will be coordinated, conducted, and monitored primarily by 
 
, BA, protocol director. Co-investigators, 
, MD, MS, 
, MPH, 
, MD, and 
, MD, MPH will also monitor the study.  
 
1.4 Links with other projects 
 
Not applicable. 
 
1.5 Main problems anticipated 
 
Problems anticipated include difficulty recruiting participants and obtaining pain scores during 
procedure.  
 
Difficulty recruiting participants: Given participants agreeing to participate in the study may be 
randomized to a smaller dose of pain medication, they may be reluctant to enroll. Rigorous chart 
review to increase number of screened participants and adequate education of clinical research 
coordinators will be necessary to enroll the appropriate number of participants.  
 
Obtaining pain scores: As there are many points at which pain scores will be assessed during 
what is a fairly quick procedure, it may be difficult for both the clinical research coordinator to 
obtain and the participant to provide scores at the correct time points. Building a strong 
relationship with both the provider and the participant will be essential for obtaining the pain 
scores at the appropriate time points.  
 
1.6 Expected outcomes of the study and dissemination of findings 
 
If our hypothesis is true, our technique will be seen as non-inferior to a technique of cervical 
block using 20 mL 2-site injection to control cervical dilation pain. The implications of these 
findings give evidence for a new technique and could have large implications in terms of cost-
savings, pain control, and side effect minimization.  
 
Analysis will occur upon completion of study enrollment. The co-investigators plan to prepare at 
least one manuscript for submission to a peer-reviewed journal. In addition, the co-investigators 
will present the results of the study at conferences and meetings where appropriate.  
 
1.7 References 
 
 
i O’Connell K, Jones HE, Simon M, Saporta V, Paul M, Lichtenberg ES. First-trimester surgical 
abortion practices: a survey of National Abortion Federation members. Contracep- tion 

 
2009;79:385–92.  
 
ii Renner RM, Nichols MD, Jensen JT, Li H, Edelman AB. Paracervical block for pain control in 
first-trimester surgical abortion: a randomized controlled trial. Obstet Gynecol 2012;119: 1030–
7. 
 
iii Glantz JC, Shomento S. Comparison of paracervical block techniques during first trimester 
pregnancy termination. Int J Gynaecol Obstet 2001;72:171–8.   
iv Wiebe ER. Comparison of the efficacy of different local anesthetics and techniques of local 
anesthesia in therapeutic abortions. Am J Obstet Gynecol 1992;167:131– 4. 
 
v Cetin A, Cetin M. Effect of deep injections of local anesthetics and basal dilatation of cervix in 
management of pain during legal abortions. A randomized, controlled study. Contraception 
1997;56:85–7. 
 
vi Donati S, Medda E, Proietti S, Rizzo L, Spinelli A, Subrizi D, et al. Reducing pain of first 
trimester abortion under local anaesthesia. Eur J Obstet Gynecol Reprod Biol 1996;70:145–9. 
 
vii Phair N, Jensen JT, Nichols MD. Paracervical block and elective abortion: the effect on pain 
of waiting between injection and procedure. Am J Obstet Gynecol 2002;186:1304–7. 
 
viii Renner RM, Edelman AB, Nichols MD, Jensen JT, Lim JY, Bednarek PH. Refining 
paracervical block techniques for pain control in first trimester surgical abortion: a randomized 
controlled noninferiority trial. Contraception 2016;94: 461-6. 
 
ix Prescriber’s Digital Reference. Lidocaine drug summary and recommended dosage for 
paracervical block. http://www.pdr.net/drug-summary/Lidocaine-Hydrochloride-Injection-
lidocaine-hydrochloride-3301.2673 Retrieved on October 24, 2017. 
 
x Chanrachakul B, Likittanasombut P, O-Prasertsawat P, Herabutya Y. Lidocaine versus plain 
saline for pain relief in fractional curettage: a randomized controlled trial. Am J Obstet Gynecol 
2001;98(4):592–5.  
xi Renner RM, Jensen JT, Nichols MD, Edelman AB. Pain control in first-trimester surgical 
abortion: a systemiatic review of randomized controlled trials. Contraception 2010; 81: 372-88. 
 
xiii Soon R, Tschann M, Salcedo J, Stevens K, Ahn HJ, Kaneshiro B. Paracervical Block for 
Laminaria Insertion Prior to Second-Trimester Abortion: A Randomized Controlled Trial. Obstet 
Gynecol 130 (2), 387-392. 8 2017