Methylene blue: the drug of choice for catecholamine-refractory vasoplegia after cardiopulmonary bypass?
OBJECTIVE
Vasoplegia is a frequent complication after cardiopulmonary bypass that often requires the application of norepinephrine. In a number of cases, however, vasoplegia is refractory to norepinephrine. The guanylate cyclase inhibitor methylene blue could be an attractive treatment alternative in such cases. This study examines the results of methylene blue therapy for norepinephrine-refractory vasoplegia after cardiopulmonary bypass.


METHODS
A total of 54 patients with norepinephrine-refractory vasoplegia after cardiopulmonary bypass were treated with methylene blue (2 mg/kg) administered intravenously through a period of 20 minutes. The effects on hemodynamics, norepinephrine dosage, and clinical outcome were evaluated.


RESULTS
Three patients (5.6%) died during the hospital stay. A clinically relevant increase in systemic vascular resistance and a decrease in norepinephrine dosage were observed in 51 patients within 1 hour after methylene blue infusion. Four patients (7.4%) had no response to methylene blue. No adverse effects related to methylene blue were observed.


CONCLUSIONS
A single dose of methylene blue seems to be a potent approach to norepinephrine-refractory vasoplegia after cardiopulmonary bypass for most patients, with no obvious side effects. Guanylate cyclase inhibitors could be a novel class of agents for the treatment of norepinephrine-refractory vasoplegia after cardiopulmonary bypass. A controlled clinical trial is now needed to evaluate the role of methylene blue in this situation.
Leyh
Rainer G
RG
Division of Thoracic and Cardiovascular Surgery, Hannover Medical School, Hannover, Germany. leyh@thg.mh-hannover.de
Kofidis
Theo
T
Strüber
Martin
M
Fischer
Stefan
S
Knobloch
Karsten
K
Wachsmann
Bjoern
B
Hagl
Christian
C
Simon
Andre R
AR
Haverich
Axel
A
D002315:Cardiopulmonary Bypass; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D005260:Female; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors*; D006801:Humans; D008297:Male; D008751:Methylene Blue / Q000627:therapeutic use*; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology; D011183:Postoperative Complications; D014652:Vascular Diseases / Q000188:drug therapy; D014655:Vascular Resistance / Q000187:drug effects*
D004791:Enzyme Inhibitors; D006162:Guanylate Cyclase; D008751:Methylene Blue; D009638:Norepinephrine