title: Association of low non-invasive near-infrared spectroscopic measurements during initial trauma resuscitation with future development of multiple organ dysfunction.
abstract: BACKGROUND
  Near-infrared spectroscopy (NIRS) non-invasively monitors muscle tissue oxygen saturation (StO2). It may provide a continuous noninvasive measurement to identify occult hypoperfusion, guide resuscitation, and predict the development of multiple organ dysfunction (MOD) after severe trauma. We evaluated the correlation between initial StO2 and the development of MOD in multi-trauma patients.
  
  
  METHODS
  Patients presenting to our urban, academic, Level I Trauma Center/Emergency Department and meeting standardized trauma-team activation criteria were enrolled in this prospective trial. NIRS monitoring was initiated immediately on arrival with collection of StO2 at the thenar eminence and continued up to 24 hours for those admitted to the Trauma Intensive Care Unit (TICU). Standardized resuscitation laboratory measures and clinical evaluation tools were collected. The primary outcome was the association between initial StO2 and the development of MOD within the first 24 hours based on a MOD score of 6 or greater. Descriptive statistical analyses were performed; numeric means, multivariate regression and rank sum comparisons were utilized. Clinicians were blinded from the StO2 values.
  
  
  RESULTS
  Over a 14 month period, 78 patients were enrolled. Mean age was 40.9 years (SD 18.2), 84.4% were male, 76.9% had a blunt trauma mechanism and mean injury severity score (ISS) was 18.5 (SD 12.9). Of the 78 patients, 26 (33.3%) developed MOD within the first 24 hours. The MOD patients had mean initial StO2 values of 53.3 (SD 10.3), significantly lower than those of non-MOD patients 61.1 (SD 10.0); P=0.002. The mean ISS among MOD patients was 29.9 (SD 11.5), significantly higher than that of non-MODS patients, 12.1 (SD 9.1) (P<0.0001). The mean shock index (SI) among MOD patients was 0.92 (SD 0.28), also significantly higher than that of non-MODS patients, 0.73 (SD 0.19) (P=0.0007). Lactate values were not significantly different between groups.
  
  
  CONCLUSIONS
  Non-invasive, continuous StO2 near-infrared spectroscopy values during initial trauma resuscitation correlate with the later development of multiple organ dysfunction in this patient population.
authors.affiliation: Department of Emergency Medicine, Wake Forest School of Medicine, 2nd Meads Hall, Medical Center Boulevard, Winston Salem, NC 27157, USA.
authors.forename: Bret A
authors.initials: BA
authors.lastname: Nicks
authors.affiliation: Department of Emergency Medicine, Wake Forest School of Medicine, 2nd Meads Hall, Medical Center Boulevard, Winston Salem, NC 27157, USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Campons
authors.affiliation: Department of Emergency Medicine, Wake Forest School of Medicine, 2nd Meads Hall, Medical Center Boulevard, Winston Salem, NC 27157, USA.
authors.forename: William P
authors.initials: WP
authors.lastname: Bozeman
keywords: Injury severity score; Lactate; Multiple organ dysfunction; Near-infrared spectroscopy; Shock index