title: Preoperative methylene blue administration in patients at high risk for vasoplegic syndrome during cardiac surgery.
abstract: BACKGROUND
  Angiotensin-converting enzyme inhibitors, calcium channel blockers, and preoperative intravenous heparin use are independent risk factors for vasoplegic syndrome after cardiac surgery. We prospectively studied whether preoperative methylene blue administration would prevent the vasoplegic syndrome in these high-risk patients.
  
  
  METHODS
  One hundred patients scheduled for coronary artery bypass graft surgery who were at high risk for vasoplegia because they were preoperatively using angiotensin-converting enzyme inhibitors, calcium channel blockers, and heparin were randomly assigned to either receive preoperative methylene blue (group 1, n = 50) or not receive it (group 2, controls, n = 50). Methylene blue (1% solution) was administered intravenously at a dose of 2 mg/kg for more than 30 minutes, beginning in the intensive care unit 1 hour before surgery.
  
  
  RESULTS
  Although similar in terms of all demographic and operative variables, the two groups differed significantly in terms of vasoplegic syndrome incidence (0% in group 1[0 of 50] vs 26% in group 2 [13 of 50]; p < 0.001). In 6 patients, the vasoplegic syndrome was refractory to norepinephrine. Four of these patients survived; the other 2 had vasoplegic syndromes that were refractory to aggressive vasopressor therapy, and they ultimately died of multiorgan failure. Stroke occurred in 1 patient. The two study groups also differed significantly in terms of average intensive care unit stay (1.2 +/- 0.5 days in group 1 vs 2.1 +/- 1.2 days in group 2; p < 0.001) and average hospital stay (6.1 +/- 1.7 days in group 1 vs 8.4 +/- 2.0 days in group 2; p < 0.001).
  
  
  CONCLUSIONS
  Our results suggest that preoperative methylene blue administration reduces the incidence and severity of vasoplegic syndrome in high-risk patients, thus ensuring adequate systemic vascular resistance in both operative and postoperative periods and shortening both intensive care unit and hospital stays.
authors.affiliation: Department of Cardiovascular Surgery, Gülhane Military Medical Academy, Ankara, Turkey.
authors.forename: Ertuğrul
authors.initials: E
authors.lastname: Ozal
authors.forename: Erkan
authors.initials: E
authors.lastname: Kuralay
authors.forename: Vedat
authors.initials: V
authors.lastname: Yildirim
authors.forename: Selim
authors.initials: S
authors.lastname: Kilic
authors.forename: Cengiz
authors.initials: C
authors.lastname: Bolcal
authors.forename: Nezihi
authors.initials: N
authors.lastname: Kücükarslan
authors.forename: Celalettin
authors.initials: C
authors.lastname: Günay
authors.forename: Ufuk
authors.initials: U
authors.lastname: Demirkilic
authors.forename: Harun
authors.initials: H
authors.lastname: Tatar
mesh_terms: D000368:Aged; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008751:Methylene Blue / Q000008:administration & dosage / Q000627:therapeutic use*; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000517:prevention & control; D011300:Preoperative Care; D013577:Syndrome; D014655:Vascular Resistance / Q000187:drug effects*
chemical_list: D008751:Methylene Blue