Misinterpretation of the sublingual microcirculation during therapy with levosimendan

There is increasing evidence in the literature that preoperative treatment with levosimendan optimizes cardiopulmonary haemodynamics in patients scheduled for the implantation of a Left Ventricular Assist Device (LVAD). The present case report describes changes in sublingual microcirculation using incident dark field video microscopy in a patient, who received a continuous infusion of 0.5 mg/h levosimendan 12 h before LVAD implantation. Despite no evident macrohaemodynamic or metabolic changes, there was a dramatic reduction in total vessel density and perfused vessel density suggesting a deterioration of microcirculation according to the consensus conference criteria in vessels smaller than 20 μm in diameter. However, the microcirculation of all visible vessels (regardless of diameter) was maintained. This potential misinterpretation is explained by a levosimedan-induced vasodilation and the subsequent reduction of the percentage of vessels with a diameter smaller than 20 μm. Physicians should carefully consider this pitfall of applying the consensus conference criteria in vasodilator-treated patients.