title: Effect of alertness level and backrest elevation on skin interface pressure.
abstract: BACKGROUND
  Critically ill patients may experience reduced mobility and sensation related to various pharmacologic therapies and treatments, making this patient population especially susceptible to pressure ulcers. An alert patient may be better able to reposition in response to discomfort, therefore preventing the development of pressure ulcers. However, little is known about the effect of an individual's alertness level on skin interface pressures. This study describes the effect of alertness level and backrest elevation on skin interface pressures.
  
  
  METHODS
  Fifty healthy participants were recruited from the Virginia Commonwealth University (Richmond, VA) population. Participants simulated each of 2 alertness levels (sedated or alert) while in 3 backrest elevations (30°, 45°, or 60°). Activity level, backrest elevation, and interface pressures were recorded continuously for 30 seconds. Random effects models were used to examine the effects of alertness level and backrest elevation on average and peak pressure. Participants had a mean age of 30 and 82% were female.
  
  
  RESULTS
  There was a significant interaction between alertness level and angle as related to average pressure (P < 0.0001) and peak pressure (P < 0.0001). Increases in backrest elevation increased average pressure and peak pressure. Interface pressures were generally greater when participants were simulating the alert state.
  
  
  CONCLUSIONS
  These findings may indicate that interface pressure is a poor indicator of patient discomfort. Higher body mass index (BMI) was associated with higher average pressure (P < 0.0001), but lower peak pressure (P < 0.0001), suggesting better pressure distribution across the patient's body area. These findings are similar to previous studies in which low BMI is associated with increased pressure ulcer risk. ﻿﻿﻿.
authors.affiliation: Virginia Commonwealth University, Richmond, VA; email: aapepperl@vcu.edu.
authors.forename: Anathea Abad
authors.initials: AA
authors.lastname: Pepperl
authors.affiliation: Virginia Commonwealth University, Richmond, VA.
authors.forename: Melissa Bucalan
authors.initials: MB
authors.lastname: Rooney
authors.affiliation: Virginia Commonwealth University, Richmond, VA.
authors.forename: Angela
authors.initials: A
authors.lastname: Parker
authors.affiliation: Virginia Commonwealth University, Richmond, VA.
authors.forename: Ruth Srednicki
authors.initials: RS
authors.lastname: Burk
authors.affiliation: Air Force Institute of Technology, Dayton, OH.
authors.forename: Christine Schubert
authors.initials: CS
authors.lastname: Kabban
authors.affiliation: Virginia Commonwealth University, Richmond, VA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Wetzel
authors.affiliation: Virginia Commonwealth University, Richmond, VA.
authors.forename: Mary Jo
authors.initials: MJ
authors.lastname: Grap