Clinical trial NCT03187041: Sensation and Skin Pressures Under Blood-Draw Tourniquets
Official title: Skin Surface Pressures Under Blood-Draw Tourniquets
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Skin Pressures Under Blood Draw-tourniquets
Keywords: blood draw tourniquets
skin surface pressure
blood draw band
elastic tourniquet
phlebotomy
tourniquet pressure
Lead sponsor: University of California, San Diego
Sponsor class: OTHER
First posted: 2017-06-14
Enrollment: 10
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: In order to acquire our data, a Microlab PicoPress device will be employed. It has been shown to provide accurate, linear, and reproducible measures of surface pressure between the skin and device. For tourniquets, the investigators will be using a MedSource perforated tourniquet, which is the type of elastic tourniquet the phlebotomists are accustomed to using in their daily practice. For each experiment throughout both phases of the study, the PicoPress pressure sensor will be folded in half and taped over the lateral aspect of the right arm, approximately 2 inches distal to the deltoid muscle along the brachialis muscle. Arm circumferences will be taken prior to experimentation at this same location. For each trial, the phlebotomists will tie the 2.5cm elastic tourniquet around the arm and pressure sensor while ensuring that the tourniquet is not knotted directly on top of the sensor. The study will be divided into two phases of experimentation conducted sequentially.
Primary purpose: BASIC_SCIENCE

Brief summary: 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

Detailed 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.

Eligibility criteria: 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.

Primary outcomes:
measure: Skin Surface Pressure Under Blood-Draw Tourniquet with Phlebotomists (Phase 1)
timeFrame: Phase 1: 10-15 seconds (10 times within a 5 -10 minute period)
measure: Skin Surface Pressure Under Blood-Draw Tourniquet and Change in sensation during a 1 hour period (Phase 2)
timeFrame: Phase 2: 70 minutes (sensation will be measured every 10 minutes)
Secondary outcomes:
Other outcomes:
Locations:
city: San Diego
country: United States
facility: UC San Diego Medical Center
state: California
Study officials:
affiliation: UCSD
name: Alan R Hargens, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Crenshaw AG, Hargens AR, Gershuni DH, Rydevik B. Wide tourniquet cuffs more effective at lower inflation pressures. Acta Orthop Scand. 1988 Aug;59(4):447-51. doi: 10.3109/17453678809149401.
citation: Partsch H, Mosti G. Comparison of three portable instruments to measure compression pressure. Int Angiol. 2010 Oct;29(5):426-30.