AUTHORS
Alberto Ramírez-Saiz
Gisela Palma-Aguilar
KEY WORDS
Methylene blue, vasoplegic syndrome, cardiac surgery, refractory hypotension, meta-analysis.
ABSTRACT
Introduction and goals: Methylene blue (MB) is used in the treatment of refractory hypotension associated with vasoplegic syndrome during cardiac surgery. This study aims to assess adverse effects and mortality in patients treated with MA, as well as to analyse the length of hospital stay and perform a meta-analysis of safety in the context of cardiac surgery.
Material and methods: A systematic review was conducted following PRISMA guidelines. Randomised clinical trials with control group in patients aged 18 years and older treated with MB after cardiac surgery were included. The meta-analysis used a Bayesian methodology to assess adverse effects and morbidity and mortality events.
Results: Of the 29 studies identified, five met the inclusion criteria. The results showed that MB was associated with a significant reduction in postoperative bleeding and hospital stay. No significant differences were found in the incidence of renal failure, stroke or need for dialysis. However, one study that administered MB after diagnosis of vasoplegic syndrome reported a reduction in multi-organ failure and mortality. The meta-analysis showed inconclusive evidence on the overall safety of MB.
Conclusions: MB may be effective in reducing bleeding complications and mortality in patients with vasoplegic syndrome after cardiac surgery. However, the relative lack of studies and the variability in the doses used limit the generalisation of thee results, underlining the need for more high-quality research.