title: The prognostic value of muscle regional oxygen saturation index in severe community-acquired pneumonia: a prospective observational study.
abstract: BACKGROUND
  Community-acquired pneumonia (CAP) mortality exceeds 20 % in critical care patients despite appropriate antibiotic therapy. Regional tissue oxygen saturation index (rSO2) measured with near-infrared spectroscopy (NIRS) might facilitate early detection for patients at risk of serious complications. Our objectives were to determine the relationship between early determination of rSO2 and mortality and to compare discrimination power for mortality of rSO2 and other resuscitation variables in critically ill CAP patients.
  
  
  METHODS
  This is a prospective observational study. Patients with CAP were enrolled within 6 h to intensive care admission. Demographics and clinical variables were recorded. rSO2 was determined using NIRS in brachioradialis muscle. All variables were determined at baseline and 24 h after admission.
  
  
  RESULTS
  Forty patients were enrolled. Fourteen patients (35 %) had a baseline rSO2 < 60 % and 7 of them died (50 %). Only 1 of 26 (3.8 %) patients with rSO2 ≥ 60 % died (p = 0.007). The area under ROC curve (AUROC) showed consistent mortality discrimination at baseline (0.84, p = 0.03) and at 24 h (0.86, p = 0.006) for rSO2 values. Cox regression analysis showed that "low" rSO2 at ICU admission (hazard ratio (HR) = 8.99; 95 % confidence interval (CI) 1.05-76.8; p = 0.045) and "low" rSO2 at 24 h (HR = 13.18; 95 % CI 1.52-113.6; p = 0.019) were variables independently associated with mortality. In contrast, other variables such as Acute Physiology and Chronic Health Evaluation (APACHE II) score (HR = 1.09; 95 % CI 0.99-1.19; p = 0.052) were not associated with mortality.
  
  
  CONCLUSIONS
  Our findings suggest that forearm skeletal muscle rSO2 differs in patients with severe CAP according to outcome and might be an early prognosis tool.
authors.affiliation: Joan XXIII University Hospital, Critical Care Department, IISPV/URV, Carrer Dr. Mallafre Guasch 4, 43007, Tarragona, Spain ; Research Unit, Joan XXIII University Hospital, IISPV/URV, Tarragona, Spain.
authors.forename: Laura
authors.identifier: 0000-0002-7170-3788
authors.initials: L
authors.lastname: Claverias
authors.affiliation: Joan XXIII University Hospital, Critical Care Department, IISPV/URV, Carrer Dr. Mallafre Guasch 4, 43007, Tarragona, Spain.
authors.forename: Michael
authors.initials: M
authors.lastname: Marí
authors.affiliation: Joan XXIII University Hospital, Critical Care Department, IISPV/URV, Carrer Dr. Mallafre Guasch 4, 43007, Tarragona, Spain.
authors.forename: Judith
authors.initials: J
authors.lastname: Marín-Corral
authors.affiliation: Joan XXIII University Hospital, Critical Care Department, IISPV/URV, Carrer Dr. Mallafre Guasch 4, 43007, Tarragona, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Magret
authors.affiliation: Joan XXIII University Hospital, Critical Care Department, IISPV/URV, Carrer Dr. Mallafre Guasch 4, 43007, Tarragona, Spain ; Research Unit, Joan XXIII University Hospital, IISPV/URV, Tarragona, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Trefler
authors.affiliation: Joan XXIII University Hospital, Critical Care Department, IISPV/URV, Carrer Dr. Mallafre Guasch 4, 43007, Tarragona, Spain ; Research Unit, Joan XXIII University Hospital, IISPV/URV, Tarragona, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Bodí
authors.affiliation: Research Unit, Joan XXIII University Hospital, IISPV/URV, Tarragona, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: García-España
authors.affiliation: Critical Care Department, Mataró Hospital, Mataró, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Yébenes
authors.affiliation: CIBER de enfermedades respiratorias (CIBERES), ISC III, Bunyola Palma de Mallorca, Spain ; Parc de Salut Mar, IMIM, Pneumology Department, CEXS, UPF, Barcelona, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Pascual
authors.affiliation: CIBER de enfermedades respiratorias (CIBERES), ISC III, Bunyola Palma de Mallorca, Spain ; Parc de Salut Mar, IMIM, Pneumology Department, CEXS, UPF, Barcelona, Spain.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Gea
authors.affiliation: Joan XXIII University Hospital, Critical Care Department, IISPV/URV, Carrer Dr. Mallafre Guasch 4, 43007, Tarragona, Spain ; Research Unit, Joan XXIII University Hospital, IISPV/URV, Tarragona, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Rodríguez
keywords: Community-acquired pneumonia; Microcirculation; Near-infrared spectroscopy; Sepsis; Septic shock