Effect of Tourniquet Use on Muscle Thigh Function.

Study Overview
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Brief Summary
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The use of a pneumatic tourniquet with the purpose of maintaining an operative field free of blood is a common practice in orthopedic surgery. Its use is associated with local and systemic consequences related to hemodynamic and reperfusion ischemia phenomena. Although is known that its use is not an innocuous measure, there is still certain degree blurriness regarding the potential metabolic and functional consequences that may result in the involved limb. In this trial, the investigators are setting out to discriminate the effect of the pneumatic tourniquet on thigh muscle function (strength, tone and activation). The hypothesis is that the pneumatic tourniquet by itself causes a significant postoperative muscular dysfunction of the quadriceps and, thus, the main outcome will be the presence of postoperative quadriceps muscle dysfunction, defined as a fall greater than or equal to 10% of the maximal voluntary isometric contraction measured at 24 hours post surgery.

Official Title
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Effect of the Use of Tourniquet in the Thigh: a Biomechanical Analysis on the Muscular Function of the Quadriceps in the Postoperative Period.

Conditions
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Muscle Weakness, Pneumatic Tourniquet

Intervention / Treatment
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* Device: Pneumatic tourniquet use


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing forefoot surgery that requires the use of a pneumatic tourniquet American Society of Anesthesiologists classification 1-3 Exclusion Criteria: Ambulatory surgery Adults who are unable to give their own consent Pre-existing neuropathy or myopathy Contraindication of tourniquet use Bilateral surgery Pregnancy Hip, thigh, knee, leg or ankle pathologies that prevent or contraindicate using a dynamometer, tonometer or surface electromyographer Arterial hypertension with systolic pressures above 200mmHg Renal failure Hepatic failure

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Surgical Side<br>Surgical side requiring the use of a pneumatic tourniquet. | Device: Pneumatic tourniquet use<br>* Surgery requiring a pneumatic tourniquet on the thigh<br>|
| No Intervention: Non Surgical Side<br>Contralateral side (Control Thigh). | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative muscle dysfunction | Fall greater or equal than 10% of the voluntary isometric muscle contraction from basal | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Basal upper and lower extremity blood pressures | Pre spinal anesthesia measured blood pressures | Up to 2 hours pre spinal anesthesia | 
| Upper and lower extremity blood pressures after spinal anesthesia | Post spinal anesthesia measured blood pressures | 10 minutes after spinal anesthesia | 
| Arterial occlusion pressure | Doppler estimation of arterial occlusion pressure of the lower extremity surgical side | 10 minutes after spinal anesthesia | 
| Pneumatic tourniquet inflation pressure | Arterial occlusion pressure plus a safety margin | 3 hours from tourniquet inflation | 
| Pneumatic tourniquet inflation time | Time from inflation to release of the pneumatic tourniquet | 3 hours from tourniquet inflation | 
| Quadriceps electromyographic activation profile | Basal and 24 hours (post surgery) quadriceps activation on surgical side | 24 hours | 
| Quadriceps muscle tone | Basal and 24 hours (post surgery) measurement of quadriceps muscle tone on surgical side | 24 hours | 
| Thigh perimeter | Basal and 24 hours (post surgery) bilateral measurement of thigh perimeter | 24 hours | 
| Thigh pain | Basal and 24 hours (post surgery) bilateral thigh pain measured with a numerical rating scale (0-10) | 24 hours | 
| Postoperative measurements time | Time from pneumatic tourniquet release to postoperative muscle function measurements | 24 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pneumatic Tourniquet, Postoperative Muscle Dysfunction