title: Knee area tissue oxygen saturation is predictive of 14-day mortality in septic shock.
abstract: OBJECTIVE
  Thenar eminence tissue oxygen saturation (StO(2)) was developed to assess organ perfusion. However, mottling, a strong predictor of mortality in septic shock, develops preferentially around the knee. We aimed to evaluate the prognostic value of StO(2) measured around the knee in septic shock patients and compare it to thenar StO(2).
  
  
  METHODS
  This was a prospective observational study in a tertiary teaching hospital. All consecutive patients with septic shock were included. Parameters were recorded when vasopressors were started (H0) and every 6 h during 24 h. Their predictive value was assessed on 14-day mortality.
  
  
  RESULTS
  Fifty-two patients were included. SOFA score was 11 (9-15) and SAPS II was 56 (40-72). At 6 h after ICU admission (H6), mean arterial pressure, cardiac index, and central venous pressure were not different between non-survivors and survivors; but non-survivors had higher arterial lactate level (8.8 ± 5.0 vs. 2.2 ± 1.5 mmol/l, P < 0.001), lower urinary output (0.22 ± 0.45 vs. 0.70 ± 0.50 ml/kg/h, P < 0.001) and ScvO(2) (62 ± 20 vs. 72 ± 9 %, P = 0.03). At H6, StO(2) was lower in non-survivors; this difference was not significant for thenar StO(2) (70 ± 15 vs. 77 ± 12 %, P = 0.10) but was very pronounced for knee StO(2) (39 ± 23 vs. 71 ± 12 %, P < 0.001). At H6, a low knee StO(2) was associated with a higher mottling score (P < 0.01), a higher lactate level (P < 0.002, R (2) = 0.2), and a lower urinary output (P = 0.02, R (2) = 0.12).
  
  
  CONCLUSIONS
  After initial septic shock resuscitation, StO(2) measured around the knee is a strong predictive factor of 14-day mortality.
authors.affiliation: Service de réanimation médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75571 Paris Cedex 12, France. hafid.aitoufella@sat.aphp.fr
authors.forename: H
authors.initials: H
authors.lastname: Ait-Oufella
authors.forename: J
authors.initials: J
authors.lastname: Joffre
authors.forename: P Y
authors.initials: PY
authors.lastname: Boelle
authors.forename: A
authors.initials: A
authors.lastname: Galbois
authors.forename: S
authors.initials: S
authors.lastname: Bourcier
authors.forename: J L
authors.initials: JL
authors.lastname: Baudel
authors.forename: D
authors.initials: D
authors.lastname: Margetis
authors.forename: M
authors.initials: M
authors.lastname: Alves
authors.forename: G
authors.initials: G
authors.lastname: Offenstadt
authors.forename: B
authors.initials: B
authors.lastname: Guidet
authors.forename: E
authors.initials: E
authors.lastname: Maury
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005602:France / Q000453:epidemiology; D006439:Hemodynamics / Q000502:physiology; D017052:Hospital Mortality / Q000639:trends; D006784:Hospitals, Teaching; D006801:Humans; D007362:Intensive Care Units; D007717:Knee / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012772:Shock, Septic / Q000401:mortality*; D019265:Spectroscopy, Near-Infrared; D016019:Survival Analysis