title: The Blue Coma: The Role of Methylene Blue in Unexplained Coma After Cardiac Surgery.
abstract: OBJECTIVE
  Methylene blue commonly is used as a dye or an antidote, but also can be used off label as a vasopressor. Serotonin toxicity is a potentially lethal and often misdiagnosed condition that can result from drug interaction. Mild serotonin toxicity previously was reported in settings in which methylene blue was used as a dye. The authors report 3 cases of life-threatening serotonin toxicity in patients undergoing chronic selective serotonin reuptake inhibitor (SSRI) therapy who also underwent cardiac surgery and received methylene blue to treat vasoplegic syndrome.
  
  
  METHODS
  An observational study.
  
  
  METHODS
  A cardiothoracic intensive care unit (ICU) in a teaching hospital.
  
  
  METHODS
  Three patients who received methylene blue after cardiac surgery, later discovered to be undergoing chronic SSRI therapy.
  
  
  METHODS
  None.
  
  
  RESULTS
  All 3 patients received high doses of fentanyl during general anesthesia. They all developed vasoplegic syndrome and consequently were given methylene blue in the ICU. All 3 patients developed serotonin toxicity, including coma, after this administration and diagnostic tests were negative for acute intracranial pathology. Coma lasted between 1 and 5 days. Two patients were discharged from the ICU shortly after awakening, whereas the third patient experienced a complicated postoperative course for concomitant refractory low-cardiac-output syndrome.
  
  
  CONCLUSIONS
  Patients undergoing chronic SSRI therapy should not be administered methylene blue to treat vasoplegic syndrome.
authors.affiliation: Department of Anesthesia and Intensive Care.
authors.forename: Enrico Antonio
authors.initials: EA
authors.lastname: Martino
authors.affiliation: Department of Anesthesia and Intensive Care.
authors.forename: Dario
authors.initials: D
authors.lastname: Winterton
authors.affiliation: Department of Anesthesia and Intensive Care.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Nardelli
authors.affiliation: Department of Anesthesia and Intensive Care.
authors.forename: Laura
authors.initials: L
authors.lastname: Pasin
authors.affiliation: Department of Anesthesia and Intensive Care.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Calabrò
authors.affiliation: Department of Anesthesia and Intensive Care.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Bove
authors.affiliation: Department of Neurology, IRCCS San Raffaele Scientific Institute.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Fanelli
authors.affiliation: Department of Anesthesia and Intensive Care; Vita-Salute San Raffaele University, Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Zangrillo
authors.affiliation: Department of Anesthesia and Intensive Care; Vita-Salute San Raffaele University, Milano, Italy. Electronic address: landoni.giovanni@hsr.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Landoni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003128:Coma / Q000209:etiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008751:Methylene Blue / Q000009:adverse effects*; D011183:Postoperative Complications / Q000209:etiology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects*
chemical_list: D008751:Methylene Blue; D017367:Selective Serotonin Reuptake Inhibitors
keywords: anesthesia; coma; intensive care; methylene blue; selective serotonin reuptake inhibitors; serotonin syndrome; thoracic surgery; vasoplegic syndrome