Shear Strength
Conditions
Keywords
pre-hospital transport, shear force, tissue interface pressure
Brief summary
The purpose of this study was to examine the effectiveness of a shear reduction surface on shear, pressure, and comfort used in pre-hospital ground transport.
Detailed description
This study enrolled healthy adult volunteers of any race or gender, stratified into 3 Body Mass Index (BMI) categories (≤20, 20.1-24.9, ≥25), who served as their own controls. The setting for this study was on a closed driving course utilized for training of emergency and law enforcement personnel, and the vehicle used was a standard ground ambulance affiliated with the Medical Transport of a tertiary medical center. Apparatus and/or instruments: A commercial full-length LiquiCell® anti-shear mattress overlay (ASMO) (Birchwood Laboratories, Eden Prairie MN) was placed on the standard ambulance stretcher mattress. Shear force and tissue interface pressure was measured during a full stop, acceleration, travelling at 30 mph, deceleration, and a full stop by a PREDIA device (Molten Corporation, Hiroshima Japan) through reusable sensors attached to the sacrum, ischial tuberosity, and heel. Procedures: Following written informed consent, subjects were weighed and measured with a calibrated scale to calculate a current BMI. Three PREDIA sensors were secured to three sites (sacrum, ischial tuberosity, and heel) with double-stick tape. Subjects wore standard hospital scrub bottoms, and were secured supine to the ambulance stretcher using standard procedure. Subjects were blinded to the presence of the LiquiCell® ASMO overlay by a sheet covering on the stretcher. The ASMO was placed according to a simple randomization table. The stretcher was initially be placed with 0 degree head-of-bed (HOB) elevation, followed by subsequent HOB elevations of 15 degrees and 30 degrees. HOB elevations were verified using a standard goniometer. The ambulance traveled over a closed course driven by ambulance staff members that had passed the mandatory Coaching the Emergency Vehicle Operator (CEVO) driving course. The course included at maximum speed of 30 mph and 5 complete stops at each of 3 HOB elevations (0, 15, and 30 degrees). Shear measurements (measured in Newtons) and pressure measurements (measured in mmHg) for each anatomical site were taken with the PREDIA sensors during a full stop, acceleration, travelling at 30 mph, deceleration, and a full stop for each run. At the beginning and completion of each set of 5 runs, subjects were asked to rate their discomfort on a scale of 0 (no discomfort) to 10 (worst discomfort imaginable). Following the first set of 15 runs, the course was repeated with or without the LiquiCell® ASMO according to the randomization table.
Interventions
OTHERStandard of Care
Standard ambulance stretcher mattress
DEVICEAnti-shear mattress overlay
A commercial full-length LiquiCell® anti-shear mattress overlay (ASMO) was placed on the standard ambulance stretcher mattress.
Sponsors
Mayo Clinic
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
SUPPORTIVE_CARE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy adult volunteers * 18-70 years old * Able to read and write English * Height of 6' feet tall or less * Weight under 300 lbs.
Exclusion criteria
* Non-English speaking * Pregnancy * Prisoners * Previous history of pelvic fracture, pressure ulcers on sacrum, ischial tuberosity, or heel * Adhesive allergy or sensitivity * Height over 6 feet tall * Weight over 300 lbs.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Shear Force as as measured by the PREDIA monitor | baseline, 2 hours | The PREDIA monitor is a hand-held monitor that measures both shear forced (measured in Newtons) and tissue-interface pressure (measured in mmHg) simultaneously at discrete points in time. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Tissue-Interface Pressure as measured by the PREDIA monitor | baseline, 2 hours | The PREDIA monitor is a hand-held monitor that measures both shear forced (measured in Newtons) and tissue-interface pressure (measured in mmHg) simultaneously at discrete points in time. |
| Change in Comfort Score | baseline, 2 hours | At the beginning and completion of each set of 5 runs, subjects were asked to rate their discomfort on a scale of 0 (no discomfort) to 10 (worst discomfort imaginable). |
Countries
United States
Outcome results
None listed