title: Methylene blue for postcardiopulmonary bypass vasoplegic syndrome: A cohort study.
abstract: BACKGROUND
  Methylene blue (MB) has been used to treat refractory hypotension in a variety of settings.
  
  
  OBJECTIVE
  We sought to determine whether MB improved blood pressure in postcardiopulmonary bypass (CPB) vasoplegic syndrome (VS) in a complex cardiac surgery population. Furthermore, to determine variables that predicted response to MB.
  
  
  METHODS
  This was conducted in a tertiary care medical center; this study was a retrospective cohort study.
  
  
  METHODS
  Adult cardiac surgery patients who received MB for post-CPB VS over a 2-year period were studied. Mean arterial blood pressure (MAP) and vasopressor doses were compared before and after MB, and logistic regression was used to model which variables predicted response.
  
  
  RESULTS
  Eighty-eight patients received MB for post-CPB VS during the study period. MB administration was associated with an 8 mmHg increase in MAP (P = 0.004), and peak response occurred at 2 h. Variables that were associated with a positive drug response were deep hypothermic circulatory arrest during surgery and higher MAP at the time of drug administration (P = 0.006 and 0.02). A positive response had no correlation with in-hospital mortality (P = 0.09).
  
  
  CONCLUSIONS
  MB modestly increases MAP in cardiac surgery patients with VS. Higher MAP at the time of drug administration and surgery with deep hypothermic circulatory arrest predict a greater drug response.
authors.affiliation: Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Mazzeffi
authors.affiliation: Department of Pharmacy, Children's National Medical Center, Washington, DC 20010, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Hammer
authors.affiliation: Department of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Caridi-Scheible
authors.affiliation: Department of Anesthesiology, University of California, San Francisco School of Medicine, San Francisco, CA 94131, USA.
authors.forename: James
authors.initials: J
authors.lastname: Ramsay
authors.affiliation: Department of Pharmacy, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Paciullo
mesh_terms: D000368:Aged; D002315:Cardiopulmonary Bypass; D015331:Cohort Studies; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008751:Methylene Blue / Q000627:therapeutic use*; D008875:Middle Aged; D011183:Postoperative Complications / Q000188:drug therapy*; D013577:Syndrome; D016896:Treatment Outcome; D056987:Vasoplegia / Q000188:drug therapy*
chemical_list: D004791:Enzyme Inhibitors; D008751:Methylene Blue