Relative contributions of interface pressure, shear stress, and temperature on ischemic-induced, skin-reactive hyperemia in healthy volunteers: A repeated measures laboratory study

Charlie Lachenbruch, Yi Ting Tzen, David Brienza, Patricia E. Karg, Peter A. Lachenbruch

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Although the primary risk factors for pressure ulcer development - pressure, shear, skin temperature, moisture, and friction - have been identified for decades, the relative contribution of each to this risk remains unclear. To confirm the results of and expand upon earlier research into the relative contributions of interface pressures, shear stress, and skin temperature among 4 healthy volunteers, a study involving 6 additional healthy 40- to 75-year-old volunteers was conducted and results of the 2 studies were pooled. All 3 variables (interface pressures, shear stress, and skin temperature) were systematically and randomly varied. In the prone position, volunteers each underwent 18 test conditions representing different combinations of temperature (28°C, 32°C, 36°C), pressure (8.0 and 13.3 kPa), and shear (0, 6.7, and 14.0 kPa) using a computer-controlled indenter applied to the sacrum for 20 minutes exerting weights of 100 g and 200 g to induce 0.98 N and 1.96 N of shear force, respectively. Each condition was tested twice, resulting in a total of 360 trials. Magnitude of postload reactive hyperemia as an index of ischemia was measured by laser Doppler flowmetry. Fixed effects regression models were used to predict 3 different indices of reactive hyperemic magnitude. Friedman tests were performed to compare the reactive hyperemia among 3 different skin temperatures or shear stresses under the same amount of localized pressure. In all regression models, pressure and temperature were highly significant predictors of the extent of reactive hyperemia (P <0.0001 and P <0.0001, respectively); the contributions of shear stress were not statistically significant (P ≤ 0.149). With higher temperature, reactive hyperemia increased significantly, especially at greater localized pressure and shear stress, and the difference was more profound between 32°C and 36°C than between 28°C and 32°C. These results confirm that, in laboratory settings, temperature is an important factor in tissue ischemia. Additional studies examining the relative importance of pressure, shear, and temperature and potential effects of lowering temperature on tissue ischemia in healthy volunteers and patients at risk for pressure ulcer development are warranted. Because deformation at weight-bearing areas often results in blood flow occlusion, actively lowering the temperature may reduce the severity of ischemia and lower pressure ulcer risk. In this study, shear did not appear to contribute to ischemia in the dermal tissues when assessed using laser Doppler; further work is needed to examine its effect on deeper layers, particularly with regard to nonischemic mechanisms.

Original languageEnglish (US)
Pages (from-to)16-25
Number of pages10
JournalOstomy Wound Management
Volume61
Issue number2
StatePublished - Feb 1 2015
Externally publishedYes

Fingerprint

Hyperemia
Healthy Volunteers
Pressure
Skin
Temperature
Skin Temperature
Ischemia
Pressure Ulcer
Volunteers
Sacrum
Prone Position
Laser-Doppler Flowmetry
Friction
Weight-Bearing
Thromboplastin
Lasers
Weights and Measures
Research

Keywords

  • nontherapeutic human experimentation
  • pressure
  • reactive hyperemia
  • shear
  • temperature ischemia

ASJC Scopus subject areas

  • Internal Medicine
  • Nursing(all)
  • Gastroenterology

Cite this

Relative contributions of interface pressure, shear stress, and temperature on ischemic-induced, skin-reactive hyperemia in healthy volunteers : A repeated measures laboratory study. / Lachenbruch, Charlie; Tzen, Yi Ting; Brienza, David; Karg, Patricia E.; Lachenbruch, Peter A.

In: Ostomy Wound Management, Vol. 61, No. 2, 01.02.2015, p. 16-25.

Research output: Contribution to journalArticle

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