Painless Local Anaesthesia With Bicarbonate Admixture

Study Overview
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Brief Summary
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This study examines whether the injection of local anesthesia mixed with sodium bicarbonate in the ratio of 3:1 creates a less burning sensation and is as effective regarding the anesthetic effect as in the ratio of 9:1.

Detailed Description
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Therefore the investigators compare two groups with 24 healthy individuals in each group in a cross-over study. One group receives four injections (two in each forearm) and one group receives only two injections (one in each forearm) The four injections of group 1 are: IMP1: Lidocaine and sodium bicarbonate ratio 3:1 IMP 2: Lidocaine and sodium bicarbonate ratio 9:1 IMP 3: Lidocaine IMP 4: Sodium cloride 0.9% (=placebo) The two injections of group 2 are IMP1 and IMP2. After each injection the individual has to rate their pain sensation on a NRS scale and afterwards the anesthetic effect gets tested by a standardized laser application.

Official Title
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Painless Local Anaesthesia With Bicarbonate Admixture: A Phase II, Monocentric, Double-blind, Randomized, Placebo-controlled Crossover Trial

Conditions
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Local Infiltration, Anesthesia

Intervention / Treatment
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* Drug: Lidocaine and sodium bicarbonate
* Drug: Lidocaine and sodium bicarbonate
* Drug: Lidocaine
* Drug: Sodium cloride 0.9%


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy male or female individuals between 18 and 75 years able to understand and speak German able to follow the instructions Exclusion criteria: oversensitivity to lidocaine or other local anesthetics of amide type or sulfites prone to bleeding, intake of aspirine or anticoagulation pregnancy skin on forearms with lesions (i.e. sunburn, wounds, eczema or other skin diseases) previous participation at the same study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group 1<br>Consisting of 24 individuals between 18 and 75 years, able to understand German, not pregnant, with no intolerance of local anesthetics, with intact skin and no skin diseases, not prone to bleeding or taking anticoagulation or aspirine. Intervention: Every individual receives four injections IMP1: Lidocaine and sodium bicarbonate ratio 3:1, IMP 2: Lidocaine and sodium bicarbonate ratio 9:1, IMP 3: Lidocaine, and IMP 4: Sodium cloride 0.9% (=placebo), namely two in every volar forearm, and has to rate the pain associated during the injection of the fluid, not the needle stitch. Afterwards the anesthetic effect on the four areals which got injected will be checked with a palomar laser after 5, 30, 60, 90, 120 and 180 minutes. | Drug: Lidocaine and sodium bicarbonate<br>* Lidocaine and sodium bicarbonate ratio 3:1<br>Drug: Lidocaine and sodium bicarbonate<br>* Lidocaine and sodium bicarbonate ratio 9:1<br>Drug: Lidocaine<br>* Lidocaine injection<br>Drug: Sodium cloride 0.9%<br>* Placebo<br>|
| Placebo Comparator: Group 2<br>Consisting of 24 different individuals than those belonging to Group 1. Between 18 and 75 years, able to understand German, not pregnant, with no intolerance of local anesthetics, with intact skin and no skin diseases, not prone to bleeding or taking anticoagulation or aspirine. Intervention: Every individual receives two injections: IMP 3 Lidocaine, and IMP 4 Sodium cloride 0.9% (=placebo), namely one in every volar forearm, and has to rate the pain associated during the injection of the fluid, not the needle stitch. Afterwards the anesthetic effect on the two areals which got injected will be checked with a palomar laser after 5, 30, 60, 90, 120 and 180 minutes. | Drug: Lidocaine<br>* Lidocaine injection<br>Drug: Sodium cloride 0.9%<br>* Placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rating of injection pain between IMP1 and IMP2 | on NRS scale | 1 minute | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| rating of injection pain of IMP3 and IMP4 | on NRS scale | 1 minute | 
| rating of clinical relevance of the difference between pain sensation of the injections | participant can choose between four adjectives regarding injection pain: desirable acceptable less acceptable unacceptable | 5 minutes | 
| assessment of local anesthesia of each injection with a standardized laser | with Palomoar Synosure non-ablative Fractional CO2-Laser with 30 mJ, 15 ms | 90 minutes | 
| duration of anesthetic effect of each injection | with Palomoar Synosure non-ablative Fractional CO2-Laser with 30 mJ, 15 ms | maximum 90 minutes |