Effects of ketanserin on microcirculatory alterations in septic shock: An open-label pilot study

Introduction: Microcirculatory alterations in sepsis are associated with increased morbidity and mortality. These alterations occur despite macrohemodynamic resuscitation. Alternative pro-microcirculatory strategies, including vasodilatory drugs, have been suggested to improve capillary blood flow. Ketanserin, a serotonin receptor antagonist, is an attractive candidate because of its vasodilatory, antithrombotic, and anti-inflammatory effects. Methods: This is an open-label pilot study on the effect of ketanserin administration on microcirculatory alterations in septic shock, defined as microvascular flow index (MFI) ≤ 2.5 after a strict macrohemodynamic resuscitation protocol. Sidestream dark-field imaging was applied to assess the microcirculation. A stepwise incremental dose regiment was applied until an MFI > 2.9, the primary end point, was reached. Results: Ten patients (Acute Physiology and Chronic Health Evaluation IV scores of 115 [100-136]) were included. Baseline MFI was 1.71 (1.31-2.32) and was significantly increasing to 2.96 (2.54-3.00; P = .021) during the ketanserin infusion. The total ketanserin dose was 0.09 (0.08-0.13) mg/kg per patient in 60 (30-60) minutes. In 3 patients (30%), the ketanserin infusion was discontinued due to refractory hypotension. Conclusion: An improvement in microcirculatory perfusion was observed during ketanserin administration in patients with septic shock after macrohemodynamic resuscitation. This finding needs further exploration in a placebo-controlled setting.