Skin Pressures Under Blood Draw-tourniquets
Conditions
Keywords
blood draw tourniquets, skin surface pressure, blood draw band, elastic tourniquet, phlebotomy, tourniquet pressure
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.
Interventions
OTHERSensation and Skin Surface Pressures Under Blood-Draw Tourniquets
Phase 1: Skin surface pressures will be recorded by an investigator during each of the 10 applications of the tourniquet. All 10 tourniquet skin pressure measurements will take place in the Blood Draw clinic at the UCSD Medical Center in Hillcrest on the same day for a subject. Phase 2: The same 20 subjects will be subjected to a prolonged blood-draw tourniquet application for a duration of 70 minutes. The purpose of phase 2 is to determine whether there is an effect on sensation from prolonged blood tourniquet use. External skin pressures will not exceed 60mmHg. During this prolonged tourniquet application the investigators will monitor changes in hand sensation at 10-minute intervals using Semmes-Weinstein monofilaments on three peripheral nerves of the hand (median, radian, and ulnar).
Sponsors
University of California, San Diego
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
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.
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Skin Surface Pressure Under Blood-Draw Tourniquet with Phlebotomists (Phase 1) | Phase 1: 10-15 seconds (10 times within a 5 -10 minute period) | The pressure under blood draw tourniquets will be taken in Phases 1 and 2. During phase 1, the tourniquet will remain on the subject for a brief period of time (10-15 seconds) 10 times, allowing for enough time to acquire pressure measurements using the PicoPress device. The difference between Phase 1 and Phase 2 is that phase 1 will be performed with a phlebotomist, while phase 2 will be performed with one of the investigators for an extended period of time. |
| Skin Surface Pressure Under Blood-Draw Tourniquet and Change in sensation during a 1 hour period (Phase 2) | Phase 2: 70 minutes (sensation will be measured every 10 minutes) | Phase 2: The PicoPress will constantly monitor pressure under the arm tourniquet for one hour. The investigators will also simultaneously monitor the changes from baseline in sensation using Semmes-Weinstein Monofilaments on the radial, ulnar, and median nerves in participants. |
Countries
United States
Outcome results
None listed