A Study Investigating Ways to Make Local Anaesthetic Hand Surgery Less Painful - Reducing Tourniquet Associated Pain

Study Overview
=================
Brief Summary
-----------------
Hand surgery requires a reduced blood flow to the hand during the operation, which is achieved using a tourniquet (tightly inflated circumferential cuff) around the upper arm. However this tourniquet is painful. This study investigates whether breathing oxygen can reduce the pain associated with the tourniquet to both improve patient experience and potentially to allow longer operations to be completed under a local anaesthetic (rather than a general anaesthetic, where the patient is put to sleep, which is more costly, time consuming and risky for the patient).

Detailed Description
-----------------
This study is a randomised controlled trial of healthy volunteers (for example medical students, nurses and doctors). Each volunteer is randomised to receive either oxygen or normal air through a mask whilst wearing an inflated upper arm tourniquet and rating their pain on a scale. The equipment set-up is identical for each volunteer, with the tourniquet inflated to a pressure of 250mmHg in every person. Within each arm of the study, volunteers are again randomised to wear the tourniquet on either their dominant or non-dominant arm. The study is double-blind (the volunteer and the investigator running the test are unaware of whether oxygen or air is being received) to avoid bias. The volunteer can ask for the tourniquet to be removed at any time and will wear the tourniquet for a maximum of 30 minutes. The pain ratings and also heart rate and blood pressure are then analysed to identify whether the volunteers receiving oxygen experienced less pain or were able to tolerate the tourniquet for longer than those receiving air.

Official Title
-----------------
A Randomised Controlled Trial to Investigate Whether Oxygen Supplementation Can Extend the Time Tolerated or Reduce the Pain Associated With an Upper Limb Tourniquet for Hand Surgery Under Local Anaesthetic

Conditions
-----------------
Hand Injuries/Disease Requiring Surgery to the Hand

Intervention / Treatment
-----------------
* Drug: Oxygen
* Drug: Medical air


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy More than 18 years of age Exclusion Criteria: Diabetes Vascular disease Previous operations to arms Raynaud's disease Analgesia taken in last 24 hours Chronic pain Hypertension Allergy to any substance used in the study Unable to give valid consent to participate Obesity

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Oxygen<br>Volunteer receives oxygen at a rate of 10litres/minute by mask | Drug: Oxygen<br>* Pure oxygen delivered by simple adult oxygen mask at rate of 10 litres/minute. Commencing 3 minutes prior to tourniquet inflation and administered for a maximum of 45 minutes<br>* Other names: O2;|
| Placebo Comparator: Air<br>Volunteer receives normal air at a rate of 10litres/minute by mask | Drug: Medical air<br>* Pure medical air (21% oxygen content) delivered by simple adult oxygen mask at rate of 10 litres/minute. Commencing 3 minutes prior to tourniquet inflation and administered for a maximum of 45 minutes<br>* Other names: Piped air;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in visual analogue scale pain score with time |  | At 2 minute intervals for a total duration of 45 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate |  | Every 6 minutes for a total duration of 45 minutes | 
| Blood pressure |  | Every 6 minutes for a total duration of 45 minutes | 
| Oxygen saturations |  | Every 6 minutes for a total duration of 45 minutes | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Hand, Surgery, Tourniquet, Pain, Oxygen