Use of methylene blue in the treatment of refractory vasodilatory shock after cardiac assist device implantation: report of four consecutive cases.

Vasodilatory shock frequently occurs after cardiac surgery, particularly after cardiac assist device implantation. This complication is often associated with high mortality, especially if refractory to conventional vasoconstrictor treatment. Methylene blue, a guanylate cyclase inhibitor, has been successfully used in the management of vasodilatory shock associated with cardiopulmonary bypass. We present four successive cases after implantation of cardiac assist devices suffering from norepinephrine and vasopressin refractory severe vasodilatory shock. In all patients, administration of a single dose of methylene blue (2 mg/kg body weight) resulted in an immediate and persistent decrease in vasoconstrictor dosages and serum lactate concentrations. Despite of this benefit, all patients deceased during hospital stay, however, this was not related to the methylene blue treatment. Methylene blue seems to be a promising therapeutical option in patients with otherwise resistant vasodilatory shock after cardiac assist device implantation. However, controlled clinical trials are necessary to substantiate safety and efficacy.