Sensation and Skin Pressures Under Blood-Draw Tourniquets

University of California San Diego

Status: Completed

Conditions: Skin Pressures Under Blood Draw-tourniquets

Treatments: Other: Sensation and Skin Surface Pressures Under Blood-Draw Tourniquets

Study type: Interventional

Funder types: Other

Identifiers

NCT03187041

161885

Details and patient eligibility

About

Purpose: This research study seeks to determine whether surface pressures generated by elastic tourniquets used by phlebotomists during blood-draws can penetrate to deeper tissues where major arteries and nerves lie. Additionally, investigators will also determine the effects of prolonged tourniquet application on hand sensation using a controlled, reproducible force stimulus. In conjunction, the investigators will also track changes in skin surface pressures and pain levels over this prolonged tourniquet application. Hypothesis: The investigators hypothesize the use of common elastic tourniquets used for blood draws does not significantly impact sensation and will not elicit nerve or tissue damage. Technologies used: Monofilaments and Pressure Sensor

Full description

The objective of this study is to investigate the reproducibility and consequently the safety of common elastic tourniquet methods for blood draws. Specifically, the study will investigate whether the surface pressures produced by blood draw tourniquets when applied by experienced phlebotomists are significant enough to penetrate to deeper tissue near bone where major arteries and nerves lie. By relating factors including tourniquet width and patient arm circumference to our surface pressure measurements and comparing our results to previous literature, the investigators hope to determine the safety of current blood draw tourniquet procedures.

In addition, the investigators will track changes in skin surface pressures over time to determine if prolonged exposure to these tourniquet pressures has the potential to permanently affect nerve function and muscle in tissues near bone.

Hand sensation will be investigated during a prolonged tourniquet application trial of the study to test the effects of the generated pressures on median, ulnar, and radial nerve viability over time.

Enrollment: 10 patients

Sex: All

Ages: 18 to 75 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• 18 years or older

Exclusion criteria

• no history of abnormal heart conditions

• no history of coagulation disorders

• will not be on prescription medications that affect cardiovascular system (ex: medications that affect blood pressure or cardiac contractility etc.)**

• does not have diabetes

  • Types of medications that affect the cardiovascular system and are part of the exclusion criteria include but are not limited to: anticoagulants, antiaginals, antiarrhythmic agents, anti-hypertensive/hypotensive agents, cardenolides, cardiac stimulants, hypolipidemic agents, inotropic agents, vasoconstrictors, as well as vasodilators.

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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10 participants in 1 patient group

Skin surface pressures under tourniquets and sensation

Experimental group

Description:

Phase 1: Each phlebotomist will apply the tourniquet 10 separate times to the right arm of each subject. The tourniquet will remain on the arm for approximately ten seconds, to be able to allot enough time to collect an accurate pressure measurement. All 10 tourniquet skin pressure measurements will take place on the same day for a subject. Phase 2: 20 subjects will be subjected to a prolonged blood-draw tourniquet application for a duration of 1 hour. The purpose of phase 2 is to determine whether there is an effect on sensation from prolonged blood tourniquet use.

Treatment:

Other: Sensation and Skin Surface Pressures Under Blood-Draw Tourniquets