title: Restoring arterial pressure with norepinephrine improves muscle tissue oxygenation assessed by near-infrared spectroscopy in severely hypotensive septic patients.
abstract: OBJECTIVE
  To examine the consequences of administration of norepinephrine on muscle tissue oxygenation in severely hypotensive septic shock patients.
  
  
  METHODS
  This was a prospective observational study conducted in a medical intensive care unit of a university hospital. We included 28 septic shock patients that received early volume resuscitation. All were eligible for receiving norepinephrine because of life-threatening hypotension and low diastolic arterial pressure. Muscle tissue oxygen saturation (StO₂) and its changes during a vascular occlusion test were measured at the level of the thenar eminence using a near-infrared spectroscopy (NIRS) device. Transpulmonary thermodilution cardiac index (CI) and NIRS-derived variables were obtained before and after the mean arterial pressure (MAP) was increased by norepinephrine. The baseline StO₂ and the vascular occlusion test-derived variables of 17 healthy volunteers were measured and served as controls.
  
  
  RESULTS
  In healthy volunteers, StO₂ ranged between 75 and 90% and StO₂ recovery slopes ranged between 1.5 and 3.4%/s. Administration of norepinephrine, which was associated with an increase in MAP from 54 ± 8 to 77 ± 9 mmHg (p < 0.05), also induced increases in CI from 3.14 ± 1.03 to 3.61 ± 1.28 L/min/m² (p < 0.05), in StO₂ from 75 ± 9 to 78 ± 9% (p < 0.05) and in StO₂ recovery slope from 1.0 ± 0.6 to 1.5 ± 0.7%/s (p < 0.05).
  
  
  CONCLUSIONS
  Norepinephrine administration aimed at achieving a MAP higher than 65 mmHg in septic shock patients with life-threatening hypotension resulted in improvement of NIRS variables measured at the level of the thenar eminence.
authors.affiliation: Service de réanimation médicale, Centre Hospitalo-Universitaire de Bicêtre, Assistance Publique-Hôpitaux de Paris, EA 4046, Université Paris Sud, Le Kremlin-Bicêtre, France. jean-louis.teboul@bct.aphp.fr
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Georger
authors.forename: Olfa
authors.initials: O
authors.lastname: Hamzaoui
authors.forename: Anis
authors.initials: A
authors.lastname: Chaari
authors.forename: Julien
authors.initials: J
authors.lastname: Maizel
authors.forename: Christian
authors.initials: C
authors.lastname: Richard
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Teboul
mesh_terms: D000328:Adult; D000368:Aged; D045930:Anabolic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001158:Arteries / Q000502:physiology*; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007022:Hypotension / Q000188:drug therapy*; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D008991:Monitoring, Physiologic; D018482:Muscle, Skeletal / Q000098:blood supply*; D009639:Norethandrolone / Q000008:administration & dosage / Q000627:therapeutic use*; D010101:Oxygen Consumption / Q000187:drug effects*; D011446:Prospective Studies; D012720:Severity of Illness Index; D012772:Shock, Septic / Q000503:physiopathology*; D019265:Spectroscopy, Near-Infrared; D055815:Young Adult
chemical_list: D045930:Anabolic Agents; D009639:Norethandrolone