Efficacy of Prehospital Tourniquet Models for Arterial Occlusion in Upper and Lower Limbs

NCT06725602 | Enrolling By Invitation FDA Device

• 1 other identifier: CAAE 79807023.9.0000.5
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to compare the occlusive capability and mechanical behavior of different commercially available pre-hospital tourniquet models and the results of their application on upper and lower limbs, in order to validate the techniques proposed in international guidelines regarding proximal application on the arm and thigh ("high and tight tourniquet") and controlled application, 2 to 3 inches proximally to the injury, on the forearm and leg ("controlled tourniquet"). It is estimated that 40 volunteer individuals will be recruited, who will sign the Informed Consent Form (ICF), a group primarily composed of undergraduate and graduate students in health-related fields. Regarding inclusion and exclusion criteria, these individuals will be of both sexes, aged ≥18 and ≤60 years, with both upper and lower limbs, a Body Mass Index (BMI) ≥18.5 and ≤30 kg/m² (considering the normal and overweight range, excluding underweight and obesity ranges), and without Diabetes Mellitus (DM), Systemic Arterial Hypertension, Buerger's disease, vascular and metabolic dysfunctions affecting the limbs including lymphedema, history of neoplasms, cardiac surgeries, renal failure, recent open or closed injuries in the limbs, or any other condition suggestive of systemic or localized vascular dysfunction in the limbs. The main questions it aims to answer are: Null Hypothesis (H0): There are no significant differences in the occlusive capability between TQs and in the efficacy of total vascular occlusion (arteriovenous) depending on the application site among the segments (forearm, arm, leg, thigh). Alternative Hypothesis (H1): There are significant differences in the occlusive capability between TQs and in the efficacy of total vascular occlusion (arteriovenous) depending on the application site among the segments (forearm, arm, leg, thigh). Specific Hypothesis: TQs will present significant variations in initial tightening pressures, arterial occlusion times, and arterial occlusion pressures, evidencing differences that may affect their efficacy. Each participant will receive a total of 8 TQ applications on the arm, forearm, leg, and thigh segments bilaterally, for each of the 3 non-consecutive collection days. Vascular occlusion will be verified using Doppler ultrasound on the radial artery for upper limbs and on the posterior tibial artery for lower limbs. It is a cross-sectional and self-controlled trial, aimed at collecting primary data, with randomization of the application order regarding device, laterality, segment, and blinding of the statistical analyst regarding the applied tourniquet model.

Conditions

Hemorrhage; Hypovolemic Shock; Tourniquets

Keywords

Emergency; Trauma; Hemorrhage; Tourniquets

Outcome Measures

Primary Outcomes (2)

• Arterial Occlusion (AO)

  Dichotomous variable indicated as POSITIVE (if it occurred) or NEGATIVE (if it did not occur). Variable measured immediately after the Tightening and Securing phase, in each application.

  The measurements will be assessed after the volunteer has completed all 3 days of data collection, allowing for a comparison of the 3 study arms (TQ models).

• Arterial Occlusion Pressure (AOP)

  Continuous variable, expressed in mmHg, corresponding to the pressure exerted by the TQ on the cuff, recorded at the confirmation of arterial occlusion after locking the device. It is measured immediately after the Tightening and Securing phase, in each TQ application.

  The measurements will be assessed after the volunteer has completed all 3 days of data collection, allowing for a comparison of the 3 study arms (TQ models).

Secondary Outcomes (1)

• Initial Tightening Pressure (ITP)

  The measures will be assessed after the volunteer has participated in all 3 days of data collection, to compare the 3 arms of the study (TQ models).

Other Outcomes (2)

• Index of Experienced Discomfort (IED)

  The measurements will be assessed after the volunteer has completed all 3 days of data collection, allowing for a comparison of the 3 study arms (TQ models).

• Time to arterial occlusion (TAO)

  The measurements will be assessed after the volunteer has completed all 3 days of data collection, allowing for a comparison of the 3 study arms (TQ models).

Study Arms (3)

TQ1 (CAT)

ACTIVE COMPARATOR

Application of CAT tourniquet

Device: TQ - Proximal Application ("high and tight"); Device: TQ - Controlled application (2-3 inches)

TQ2 (T-APH)

ACTIVE COMPARATOR

Application of T-APH tourniquet

Device: TQ - Proximal Application ("high and tight"); Device: TQ - Controlled application (2-3 inches)

TQ3 (SOF)

ACTIVE COMPARATOR

Application of SOF tourniquet

Device: TQ - Proximal Application ("high and tight"); Device: TQ - Controlled application (2-3 inches)

Interventions

TQ - Proximal Application ("high and tight") DEVICE

Tourniquet application: proximal ("high and tight") on arms and thighs.

Also known as: tourniquet application, proximal, "high and tight"

TQ1 (CAT); TQ2 (T-APH); TQ3 (SOF)

TQ - Controlled application (2-3 inches) DEVICE

TQ Application: controlled (2-3 inches proximal to the injury) on forearms and legs.

Also known as: controlled application, 2-3 inches

TQ1 (CAT); TQ2 (T-APH); TQ3 (SOF)

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• have all four limbs (both upper and lower limbs)
• Body Mass Index (BMI) ≥18.5 and ≤30 kg/m² (considering the normal and overweight range, excluding underweight and obesity ranges)

You may not qualify if:

• Diabetes Mellitus (DM)
• Systemic Arterial Hypertension
• Buerger's Disease
• Vascular and metabolic dysfunctions affecting the limbs including lymphedema
• history of neoplasms
• history of cardiac surgeries
• history of renal failure
• recent open or closed injuries in the limbs
• any other condition suggestive of systemic or localized vascular dysfunction in the limbs.

Sponsors & Collaborators

• University of Sao Paulo: lead

Study Sites (1)

Ribeirão Preto Medical School USP (FMRP-USP), Experimental Surgery Department

Ribeirão Preto, São Paulo, 14040900, Brazil

Location

MeSH Terms

Conditions

Hemorrhage; Shock; Emergencies; Wounds and Injuries

Interventions

Vagotomy, Proximal Gastric

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms; Disease Attributes

Intervention Hierarchy (Ancestors)

Vagotomy; Parasympathectomy; Autonomic Denervation; Denervation; Neurosurgical Procedures; Surgical Procedures, Operative

Study Officials

• Roger W F Ronconi, PT, MSc, PhD(c)

  Faculdade de Medicina de Ribeirão Preto da USP (FMRP-USP)

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD Researcher

Model Details: It is a cross-sectional and self-controlled trial, aimed at collecting primary data, with randomization of the application order regarding device, laterality, segment, and blinding of the statistical analyst regarding the applied tourniquet model. All participants will take part in all three arms of the study (3 device models) in a randomized manner by drawing lots, so that the devices will be compared within the same participant (self-controlled). The subjects will participate on 3 non-consecutive days, during which they will draw lots to determine which device will be used, thereby distributing their participation across the three study arms in a randomized manner.

Study Record Dates

• First Submitted: November 27, 2024
• First Posted: December 10, 2024
• Study Start: December 7, 2024
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: December 30, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

BR (1)