title: Use of methylene blue in patients with refractory septic shock: impact on hemodynamics and gas exchange.
abstract: OBJECTIVE
  The purpose of this study was to assess the acute effects of methylene blue, an inhibitor of nitric oxide synthesis, on hemodynamics and gas exchange in patients with refractory septic shock in a prospective clinical trial at medical and surgical intensive care units in a tertiary university hospital.
  
  
  METHODS
  Prospective, sequential study of 10 consecutive patients admitted with severe septic shock of diverse causes and unable to achieve an adequate arterial pressure despite the use of at least two vasoactive drugs. Six of them also developed acute lung injury. All received 1 mg/kg intravenous bolus of methylene blue. Hemodynamic and respiratory parameters were measured at baseline and at 30, 60, 120, and 180 minutes after the bolus injection.
  
  
  RESULTS
  Systolic, diastolic, mean arterial blood pressure, and systemic vascular resistance increased significantly in all patients, whereas no significant changes were observed in cardiac output, oxygen consumption, or oxygen extraction ratio. Gas exchange remained unaffected in patients with acute lung injury.
  
  
  CONCLUSIONS
  Methylene blue had an acute vasopressor effect in patients with refractory septic shock, and it was not deleterious on respiratory function.
authors.affiliation: Medical Intensive Care Unit, Hospital ClinicoPontificia Universidad Catolica de Chile, Santiago.
authors.forename: M
authors.initials: M
authors.lastname: Andresen
authors.forename: A
authors.initials: A
authors.lastname: Dougnac
authors.forename: O
authors.initials: O
authors.lastname: Díaz
authors.forename: G
authors.initials: G
authors.lastname: Hernández
authors.forename: L
authors.initials: L
authors.lastname: Castillo
authors.forename: G
authors.initials: G
authors.lastname: Bugedo
authors.forename: M
authors.initials: M
authors.lastname: Alvarez
authors.forename: J
authors.initials: J
authors.lastname: Dagnino
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008751:Methylene Blue / Q000627:therapeutic use*; D008875:Middle Aged; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000187:drug effects*; D012128:Respiratory Distress Syndrome / Q000150:complications / Q000188:drug therapy; D012772:Shock, Septic / Q000150:complications / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D013997:Time Factors
chemical_list: D009569:Nitric Oxide; D008751:Methylene Blue