title: Dynamic arterial elastance predicts mean arterial pressure decrease associated with decreasing norepinephrine dosage in septic shock.
abstract: BACKGROUND
  Gradual reduction of the dosage of norepinephrine (NE) in patients with septic shock is usually left to the physician's discretion. No hemodynamic indicator predictive of the possibility of decreasing the NE dosage is currently available at the bedside. The respiratory pulse pressure variation/respiratory stroke volume variation (dynamic arterial elastance (Eadyn)) ratio has been proposed as an indicator of vascular tone. The purpose of this study was to determine whether Eadyn can be used to predict the decrease in arterial pressure when decreasing the NE dosage in resuscitated sepsis patients.
  
  
  METHODS
  A prospective study was carried out in a university hospital intensive care unit. All consecutive patients with septic shock monitored by PICCO2 for whom the intensive care physician planned to decrease the NE dosage were enrolled. Measurements of hemodynamic and PICCO2 variables were obtained before/after decreasing the NE dosage. Responders were defined by a >15% decrease in mean arterial pressure (MAP).
  
  
  RESULTS
  In total, 35 patients were included. MAP decreased by >15% after decreasing the NE dosage in 37% of patients (n = 13). Clinical characteristics appeared to be similar between responders and nonresponders. Eadyn was lower in responders than in nonresponders (0.75 (0.69 to 0.85) versus 1 (0. 83 to 1.22), P <0.05). Baseline Eadyn was correlated with NE-induced MAP variations (r = 0.47, P = 0.005). An Eadyn less than 0.94 predicted a decrease in arterial pressure, with an area under the receiver-operating characteristic curve of 0.87 (95% confidence interval (95% CI): 0.72 to 0.96; P <0.0001), 100% sensitivity, and 68% specificity.
  
  
  CONCLUSIONS
  In sepsis patients treated with NE, Eadyn may predict the decrease in arterial pressure in response to NE dose reduction. Eadyn may constitute an easy-to-use functional approach to arterial-tone assessment, which may be helpful to identify patients likely to benefit from NE dose reduction.
authors.affiliation: Department of Anaesthesiology and Critical Care, Amiens University Hospital, Place Victor Pauchet, Amiens, 80054, France. guinotpierregregoire@gmail.com.
authors.forename: Pierre-Grégoire
authors.initials: PG
authors.lastname: Guinot
authors.affiliation: Department of Anaesthesiology and Critical Care, Amiens University Hospital, Place Victor Pauchet, Amiens, 80054, France. bernard.eugenie@chu-amiens.fr.
authors.forename: Eugénie
authors.initials: E
authors.lastname: Bernard
authors.affiliation: Department of Anaesthesiology and Critical Care, Amiens University Hospital, Place Victor Pauchet, Amiens, 80054, France. levrard.melanie@chu-amiens.fr.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Levrard
authors.affiliation: Department of Anaesthesiology and Critical Care, Amiens University Hospital, Place Victor Pauchet, Amiens, 80054, France. dupont.herve@chu-amiens.fr.|INSERM U1088, Jules Verne University of Picardy, Amiens, France. dupont.herve@chu-amiens.fr.
authors.forename: Hervé
authors.initials: H
authors.lastname: Dupont
authors.affiliation: Department of Anaesthesiology and Critical Care, Amiens University Hospital, Place Victor Pauchet, Amiens, 80054, France. lorne.emmanuel@chu-amiens.fr.|INSERM U1088, Jules Verne University of Picardy, Amiens, France. lorne.emmanuel@chu-amiens.fr.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lorne
mesh_terms: D000328:Adult; D000368:Aged; D062186:Arterial Pressure / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009638:Norepinephrine / Q000008:administration & dosage*; D011446:Prospective Studies; D012372:ROC Curve; D012772:Shock, Septic / Q000188:drug therapy* / Q000503:physiopathology; D013318:Stroke Volume / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000008:administration & dosage*
chemical_list: D014662:Vasoconstrictor Agents; D009638:Norepinephrine