Clinical trial NCT04207710
Conditions: Spray Pain Safety Issues
Keywords: Pain Ease Ethyl Chloride Safety Topical anesthetic ChloraPrep Topical refrigerant Microbial growth
Sponsor: Henry Ford Health System
Start date: 2021-01-26; Completion date: 2022-02-25
Enrollment: 72 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
This study aims to determine if Gebauer's Pain Ease or Gebauer's Ethyl Chloride topical anesthetic sprays are safe for use as numbing agents prior to placing epidurals and arterial lines, based on whether they introduce increased microbial growth after application to skin. Due to the recent national shortage of lidocaine, we hope to find a suitable alternative to lidocaine for topical analgesia when placing arterial lines and epidurals. Our hypothesis is that the sprays will not affect the sterility of the area. We will compare microbial growth from three subsequent swabs taken from a single area of skin on the wrist and lower back: one with no treatment, the second after treatment with ChloraPrep, and the third after applying one of the numbing sprays. If there is significantly higher growth in the swabs containing the topical anesthetic spray versus the ChloraPrep alone, this will indicate that the sprays introduce microbes to the sites of skin.

Detailed description:
The purpose of this study is to determine whether Gebauer's Pain Ease and Ethyl Chloride topical anesthetic sprays are safe for application on the areas of skin where epidurals (lower back) and arterial lines (wrist) are placed, based on whether they introduce microbial growth to these areas. The investigators will compare microbial growth by swabbing both of these skin sites following: 1) no treatment 2) ChloraPrep treatment and 3) ChloraPrep plus numbing spray (Ethyl Chloride or Pain Ease) treatment. The cultures will then be incubated to test for anaerobic bacteria, aerobic bacteria, and mold growth. The microbial growth will be compared between the three treatment groups based on the number of colony forming units present.

Funding for the project will be from the manufacturer of the numbing sprays, Gebauer Company.

Based on power analysis, for each of the numbing sprays, a total of 72 subjects must be enrolled, with 6 swabs taken per subject (untreated, ChloraPrep, and topical anesthetic spray samples will be taken from both the wrist and lower back of each subject). A sample size of 72 pairs achieves 80 % power to detect an odds ratio of 24 using a two-sided McNemar test with a significance level of 0.05.

Arms: arm 1: An area of skin on the wrist will be swabbed before and after Chloraprep application, and then each area will be swabbed again after application of Gebauer's Ethyl Chloride topical refrigerant spray. The bacterial growth prior to and after numbing spray application will be evaluated, based on the number of colony forming units that are present. arm 2: An area of skin on the lower back will be swabbed before and after Chloraprep application, and then each area will be swabbed again after application of Gebauer's Ethyl Chloride topical refrigerant spray. The bacterial growth prior to and after numbing spray application will be evaluated, based on the number of colony forming units that are present. arm 3: An area of skin on the wrist will be swabbed before and after Chloraprep application, and then each area will be swabbed again after application of Gebauer's Pain Ease topical refrigerant spray. The bacterial growth prior to and after numbing spray application will be evaluated, based on the number of colony forming units that are present. arm 4: An area of skin on the lower back will be swabbed before and after Chloraprep application, and then each area will be swabbed again after application of Gebauer's Pain Ease topical refrigerant spray. The bacterial growth prior to and after numbing spray application will be evaluated, based on the number of colony forming units that are present.
Interventions: intervention 1: Gebauer's Pain Ease Top Aerosol Mist Spray intervention 2: Gebauer's Ethyl Chloride
Intervention descriptions: intervention 1: Topical refrigerant spray intervention 2: Topical refrigerant spray

Protocol documents:
Prot_SAP_000.pdf: 
 
 
 
 
 
 
Safety of Gebauer's Pain Ease and Gebauer's Ethyl Chloride 
 
 
NCT04207710 
 
 
11-19-2019 


 
STUDY TITLE: Study to determine the safety of ethyl chloride and pain ease sprays when used following 
chloraprep for invasive procedures 
 
1) STUDY AIM, BACKGROUND, AND DESIGN ABSTRACT  
This study aims to determine if application of Gebauer’s Pain Ease or Gebauer’s Ethyl Chloride 
numbing sprays will contaminate skin which has been prepped with chloraprep.  Due to the recent 
national shortage of lidocaine we hope to be able to find a suitable alternative to lidocaine for 
topical analgesia during invasive procedures such as arterial lines and epidurals.   Depending on the 
results of this study we will decide if it is safe to proceed to additional studies to determine if 
numbing sprays are effective alternatives to lidocaine for topical analgesia. Our plan is to compare 
the number of colony forming units (CFU) of bacteria that grow on a section of skin on the wrist and 
lower back prior to treatment, following chloraprep treatment, and following application of pain 
ease spray or ethyl chloride.  Our hypothesis is that the sprays will not affect the sterility of the area 
and that there will not be a significant increase in bacterial growth after ethyl chloride or pain ease 
spray have been added to skin treated with chloraprep. 
   
2)  SUBJECT POPULATION AND ELIGIBILITY 
We plan to ask for volunteers from Henry Ford employees.  Our exclusion criteria will include people 
who have infections at the site or have a history of hypersensitivity to either the numbing sprays or 
chloraprep. 
 
3) STUDY PROCEDURES 
Our study will involve swabbing and culturing the skin of volunteers on the wrist where an arterial 
line is place, as well as on the lower back where an epidural is placed.  First, a swab of the untreated 
area of wrist or lower back will be performed.  Second, the section of skin will be treated with 
chloraprep according to standard procedure prior arterial line or epidural placement, and this 
treated skin will be swabbed.  Third, the chloraprep-treated section of skin will be treated with 
numbing spray (either Gebaur’s Ethyl Chloride or Pain Ease). For the Pain Ease group, the spray will 
be applied up to 10 seconds or until white appears (whichever comes first).  If frosting appears, stop.  
The area that has been subsequently treated with chloraprep and numbing spray will then be 
swabbed.  These swabs will be cultured by the HFHS microbiology lab on agar plates for 48 hours 
and the number of colony forming units (CFU) will be counted.  The amount of bacterial growth will 
be compared between the untreated samples, chloraprep samples and the associated post-spray 
samples.  Funding for the project will be from Gebauer, the manufacturer of the numbing sprays. 
Based on power analysis, for each spray, a sample size of 72 subjects with 6 swabs taken per subject 
(subsequent untreated, chloraprep, and numbing spray samples taken from the wrist and lower 
back from each subject) achieves 80 % power to detect an odds ratio of 24 using a two-sided 
McNemar test with a significance level of 0.05. The odds ratio is equivalent to a difference between 
two paired proportions of 0.115 which occurs when the proportion in cell 1,2 is 0.12 and the 
proportion in cell 2,1 is 0.005. The proportion of discordant pairs is 0.125. As there are two separate 
sprays being investigated independently, the final number of subjects will be 144, with 6 swabs 
taken per subject.  
APPROVED 
 
Nov 19, 2019 
 
INSTITUTIONAL REVIEW BOARD 
 


  
  
Data Analysis and Statistical Considerations   
We will collect data on an excel spreadsheet.  We will not collect any personal health information or  
identifying information for the participants. 
4) ANTICIPATED RISKS 
There are no likely risks to participants in this study.  Less likely risks include hypersensitivity to the 
products, risk of frostbite, risk of skin pigment alteration, and Ethyl Chloride is a flammable 
substance.  We will decrease the risk of frostbite by limiting exposure to the numbing sprays to the 
initial formation of crystals on the skin.  
 
5) ANTICIPATED BENEFITS  
There are no anticipated benefits to the participants however we hope that this study will allow us 
to perform additional trials which may benefit others.  
  
6) RENUMERATION/COMPENSATION  
There will be no compensation offered to participants.  
 
7)  COSTS  
The only costs associated with this project will be the materials used.  The manufacturer of pain 
ease and ethyl chlorides sprays will cover the costs of these products.  
 
8)  ALTERNATIVES  
There are no alternatives  
 
9)  CONSENT PROCESS AND DOCUMENTATION  
Consent of volunteers will be obtained by one of the investigators prior to participation in the study.  
Participants will be given written consent and offered the opportunity to ask any questions they may 
have prior to participation in the study.  Consent forms will be signed and stored in the primary 
investigators locked office.  
 
10) WITHDRAWAL OF SUBJECTS  
There are no anticipated circumstances under which subjects will be withdrawn from research 
without their consent.  
 
11)  PRIVACY AND CONFIDENTIALITY   
No personal identifiers will be kept or obtained for participants in the study.  We will not be 
accessing the health records of patients.  
 
12)  DATA AND SAFETY MONITORING PLAN  
Data quality will be maintained by the primary investigator as well as the co-investigators.    
 
13)  QUALIFICATIONS OF THE INVESTIGATOR(S)  


Dr. Attali is the head of the obstetrical anesthesia department and has done many studies to 
improve patient care.