Effects of Cervical Lidocaine Spray on Pain Relief During Manual Vacuum Aspiration : A Randomized Controlled Trial
Phase: NA
Conditions: Pain, Procedural, Lidocaine, Obstetric Surgical Procedures
Sponsor: UdonThani Hospital

 
 
Effects of Lidocaine Spray for Pain Relief during Manual Vacuum Aspiration: A study 
protocol of a randomized controlled trial 
 
Organization Protocol ID  2566/081 I 
 
Protocol dated: 2023-10-30 
Disclosure: None declared 
Financial Support: UdonThani Hospital 
 
Corresponding author: Metha Songthamwat, Department of Obstetrics and Gynecology, 
UdonThani Hospital, UdonThani, Thailand. Tel: +66815451499,  
Email: udonhome@yahoo.com 
 
Ethics: This study protocol was approved by the UdonThani Research Ethics Committee: 
Number 2566/081 I 
 
 
 

Introduction 
 
Manual vacuum aspiration (MVA) is a frequently used gynecological procedure in 
many conditions, such as abnormal uterine bleeding or termination of pregnancy (1,2). Pain 
during the MVA procedure is often caused; when the cervix is dilated, from uterine 
contractions and pain due to the anxiety during the procedure (4). The pain during the MVA 
using a visual analogue score is an average of 4-5 (8).   
 
There are many ways to reduce pain during vacuum aspiration, both medical and non-
medical. There are many types of analgesic used, such as the nonsteroidal anti-inflammatory 
drugs, local anesthesia or general anesthesia (3,5,6,7) and the use of each  type is often 
determined by each center. A common pain relief method is intravenous analgesics, such as 
pethidine or diazepam. However, a study reported that 78.5 % of cases had severe pain (pain 
score > 7) during the procedure despite the intravenous meperidine being used for pain relief 
(7). 
 
Lidocaine is frequently used as the local analgesics to reduce pain during cervical and 
uterine procedures. The common lidocaine application is paracervical block. However, 
serious side effects have been reported. (7) The application of cervical Lidocaine spray has 
proved to be effective in; endometrial sampling and intrauterine device insertion procedures 
(7,8). This cervical lidocaine spray method is more convenient and safer when compared with 
the paracervical block technique. 
 
This study aimed to evaluate the effectiveness of using local cervical lidocaine spray 
for pain relief during MVA procedure when compare with the placebo. 
 
Methods and analysis 
Study setting & design 
 
This study is a randomized, double blinded, placebo-controlled trial conducted at 
UdonThani Hospital, UdonThani, Thailand.  
Participants/Inclusion and Exclusion criteria 
In this trial, the inclusion criteria is that the women are to be aged between 20 and 60 
years and who have an indication for requiring a MVA procedure. The exclusion criteria are 
women who have; an allergy or hypersensitivity to lidocaine, the symptoms of reproductive 
tract infection or urinary tract infection, abnormal vital signs such as low blood pressure or 
fever, chronic liver or kidney disease.  
Study methods 
 
The study details will be explained to the participants and their written informed 
consent will be obtained before their participation. The randomization will be performed by 
computer generated numbers that were prepared in opaque, sealed envelopes. The eligible 
patients will be randomly assigned into two groups by the researchers. Group 1 received 4 
puffs of 10% Lidocaine spray without adrenaline and intravenous opioid analgesic, group 2 
received 4 puffs of the placebo (normal saline with the similar packaging (should this be) to 
the 10% Lidocaine spray)  and intravenous opioid analgesic.  
 
The MVA procedure will be performed at the gynecological ward. The patients will 
be informed about the procedure. The basic characteristics and the associated factors will be 
recorded in the case record form. The steps of the MVA procedure are as follows: 
1. Participants lie in the dorsal lithotomy position. 
 

2. The 50 mg intravenous Meperidine is used for analgesia 15-20 minutes before the 
operation. 
3. The skin is cleaned using povidone iodine solution, then the sterile cloth is 
applied.  
4. A speculum is inserted and the vagina is cleaned with a povidone iodine solution. 
5. The lidocaine spray (10% Lidocaine spray without adrenaline) or the placebo 
(normal saline spray) is sprayed (4 puffs) onto the cervix. (9)  
6. A tenaculum is clamped at the 2 and 10 o'clock positions of cervix. The pain 
score using visual analogue scale is assessed by the researcher. 
7. The length of the uterine cavity is measured by a uterine sound. 
8. The Karman cannula with the vacuum syringe is used to aspirate endometrium 
tissue in the uterine cavity. The size of cannula depends on the cervical os. The 
pain score is assessed by the researcher again. 
9. After the procedure is completed, bleeding is checked and the device is removed. 
The overall pain score is assessed again.  
10. The pain level is checked at 30 minutes after the procedure 
11. The side effects of procedure are recorded such as nausea vomiting , hypotension 
,abnormal bleeding, dizziness 
To ensure confidentiality in the collection of the data, the subject identification code 
will only be used in the case record form. The information is recorded and entered in the 
Stata file and then is analyzed.   
 
Blinding 
 
Both patients and investigators are blinded in this study. The Lidocaine spray and 
placebo will be prepared by the pharmacists in similar packaging and place in opaque 
envelopes with the allocated number. 
 
Outcomes 
The primary outcome is to compare the pain scores during the operation between both 
groups. The secondary outcome is to evaluate the side effect of the local Lidocaine spray. 
The visual analog scale (scale 0-10) is used for pain evaluation. The data will be presented as 
continuous scores (with mean and standard deviation (SD), or median with interquartile range 
(IQR)) and/or as dichotomized scores (with number and percentage). All outcomes will be 
compared between groups using the mean difference and 95% confidence interval and the 
relative risk with 95% confidence. Analyses will be based on the intention-to-treat approach. 
 
Sample size 
  
Sample size is calculated by the Stata statistic program using the formula to test the 
two independent proportions. The proportion in the treatment group is 0.785, the proportion 
in the control group is 0.6(8). The calculated sample size is 97 per group and the 10% drop-
out rate is added, the total sample size is 214.  
 
Statistical analysis plan 

The baseline characteristics of the participants will be compared between the 
Lidocaine spray and the placebo groups using unpaired T-test, Mann-Whitney U test, Chi-
square test or Fisher’s exact test when appropriate. A two-sided P-value <0.05 will be 
considered statistically significant. For the primary and secondary outcomes, we will report 
the mean difference of pain scores between groups with the 95% confidence interval for the 
continuous outcome and the relative risk with the 95% confidence interval for the 
dichotomous outcomes. For the main analysis, all outcomes will be analyzed using unpaired t 
test or logistic regression analysis. All analyses will be performed according to the intention-
to-treat principle using Stata statistical program version 13. 
 
Ethics 
This study protocol was approved by the UdonThani Research Ethics Committee: Number 
2566/081 I. The study results will be published in a peer-reviewed journal and shared with 
stakeholders and participants. This protocol is submitted before analysis of the results. After 
analysis and publication, data of this study will be available from the corresponding author 
upon reasonable request 
 
Authors’ contributions 
PM, CC, MS, SS were involved in the conception and design of the study and protocol. PM, 
CC and MS collected the cases. MS and US designed the statistical analysis plan and 
analyzed the data. The manuscript was drafted by PM and MS. The manuscript will be 
reviewed and the final version of the manuscript will be approved by all authors. 
 
Funding statement 
 
This study received funding support from UdonThani Hospital.  
 
Competing interests statement 
 
All authors report no conflict of interest. 
 
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