Existence of tissue blood flow in response to external pressure in the sacral region of elderly individuals--using an optical probe prototype.
OBJECTIVE
The aim was to investigate the existence of sacral tissue blood flow at different depths in response to external pressure and compression in elderly individuals using a newly developed optical probe prototype.


METHODS
The tissue blood flow and tissue thickness in the sacral area were measured during load in 17 individuals using laser Doppler flowmetry and photoplethysmography in a combined probe, and digital ultrasound.


RESULTS
The mean age was 68.6 +/- 7.0 years. While loading, the mean compression was 60.3 +/- 11.9%. The number of participants with existing blood flow while loading increased with increased measurement depth. None had enclosed blood flow deep in the tissue and at the same time an existing more superficial blood flow. Correlation between tissue thickness and BMI in unloaded and loaded sacral tissue was shown: r = 0.68 (P = 0.003) and r = 0.68 (P = 0.003).


CONCLUSIONS
Sacral tissue is highly compressed by external load. There seems to be a difference in responses to load in the different tissue layers, as occluded blood flow in deeper tissue layers do not occur unless the blood flow in the superficial tissue layers is occluded.
Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. sara.bergstrand@liu.se
Sara
S
Bergstrand
Toste
T
Länne
Anna-Christina
AC
Ek
Lars-Göran
LG
Lindberg
Maria
M
Lindén
Margareta
M
Lindgren
D000368:Aged; D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D055096:Optical Devices; D017156:Photoplethysmography / Q000295:instrumentation; D011312:Pressure / Q000009:adverse effects*; D003668:Pressure Ulcer / Q000209:etiology / Q000503:physiopathology; D012445:Sacrococcygeal Region / Q000098:blood supply* / Q000503:physiopathology*; D012867:Skin / Q000098:blood supply; D040521:Subcutaneous Tissue / Q000098:blood supply