title: Near-infrared spectroscopy measurement of sacral tissue oxygen saturation in healthy volunteers immobilized on rigid spine boards.
abstract: BACKGROUND
  Immobilization of patients utilizing rigid spine boards (RSBs) is standard practice in the management of trauma patients. Pressure ulcers have been associated with prolonged immobilization, and the possibility exists that formation may begin when the patient is initially immobilized on the RSB. The effects may not be fully recognized because of limited research on the direct tissue effects of prolonged immobilization. Near-infrared spectroscopy is an emerging tool to measure peripheral tissue oxygen saturation (StO(2)). The purpose of this research was to study the effects of prolonged spinal immobilization on an RSB on sacral tissue oxygenation of healthy volunteers.
  
  
  METHODS
  This experimental study measured StO(2) in healthy volunteers at baseline and again after 30 minutes of immobilization on an RSB at two sites: the sacral area (intervention) and 8-10 cm above the buttocks (control). Tissue oxygenation was measured with the InSpectra Tissue Oxygenation Monitor (Hutchinson Technology, Hutchinson, MN) by placing the probe at the measurement site and waiting for 15 seconds for equilibration prior to recording StO(2). Data were analyzed utilizing mixed-model and within-subjects analysis of variance (ANOVA), chi-square, and t-tests.
  
  
  RESULTS
  Seventy-three participants were included in the analysis. A slight majority of participants were female (55%), the average age was 38 years, the average height was 170 cm, and the average weight was 82 kg. There was a significant increase in the StO(2) percentage at the sacral (intervention) area following immobilization, p < 0.001, point biserial correlation (r(pb)) = 0.48. Significant changes in oxygenation were not noted at the control site.
  
  
  CONCLUSIONS
  An increase in sacral tissue oxygenation following immobilization was a finding consistent with other research. This is likely a result of initial, rapid tissue reperfusion at the time of pressure release. Rapid reperfusion indicates that a period of previous hypoperfusion has occurred. This research indicates that there are detrimental effects of spine board immobilization in healthy volunteers, which suggests that pressure ulcer formation may begin prior to hospital admission with immobilization on an RSB.
authors.affiliation: The Department of Preventive Medicine & Public Health, University of Kansas School of Medicine-Wichita, Wichita, KS 67214, USA. gberg@kumc.edu
authors.forename: Gina
authors.initials: G
authors.lastname: Berg
authors.forename: Sue
authors.initials: S
authors.lastname: Nyberg
authors.forename: Paul
authors.initials: P
authors.lastname: Harrison
authors.forename: Jessica
authors.initials: J
authors.lastname: Baumchen
authors.forename: Erin
authors.initials: E
authors.lastname: Gurss
authors.forename: Emily
authors.initials: E
authors.lastname: Hennes
mesh_terms: D000328:Adult; D003238:Connective Tissue / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D003668:Pressure Ulcer; D012149:Restraint, Physical; D012445:Sacrococcygeal Region / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared