BackgroundAlthough methylene blue and hydroxocobalamin are commonly used as rescue treatments for refractory shock, large-scale head-to-head trials comparing these agents are lacking. This study aimed to evaluate their effects on vasopressor doses in patients with refractory shock.MethodsA retrospective observational study was conducted among patients who received methylene blue or hydroxocobalamin for refractory shock. The primary endpoint was the change in vasopressor dose 24 hours after administration. Secondary outcomes included changes in mean arterial pressure and vasopressor dose over 24 hours (0, 6, 12, and 24 hours), time to vasopressor discontinuation, vasopressor-free days at 28 days, ICU and hospital length of stay, and hospital mortality.ResultsA total of 303 patients who received methylene blue (n=269) or hydroxocobalamin (n=34) were included. The mean reduction in vasopressor doses over 24 hours was similar (methylene blue 0.36 mcg/kg/min vs hydroxocobalamin 0.33 mcg/kg/min, p=0.588). The mean reduction from baseline was significant in both groups at 6, 12, and 24 hours after administration (p<0.001 each). The methylene blue group had a higher in-hospital mortality rate (78% vs 59%, OR 2.4 95% CI 1.2-5.1) and shorter median time to death (18 hours vs 106 hours, p = 0.003). However, among patients alive at discharge, there was no statistically significant difference between methylene blue and hydroxocobalamin in time to discontinuation of vasopressors (90 hours vs 129 hours), ICU length of stay (19 days vs 33 days), hospital length of stay (33 days vs 54 days), or vasopressor-free days at 28 days (18 days vs 14 days).ConclusionAmong patients with refractory shock, methylene blue and hydroxocobalamin were associated with significant reductions in vasopressor doses over 24 hours; however, no significant difference was observed between the two agents.
Leung et al. (Tue,) studied this question.