Assessment of Microcirculatory Dysfunction in Septic Shock Patients by OCTA

Purpose and rationale: Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis and septic shock are major public health problems killing one in every three patients. Microcirculatory dysfunction is frequent in septic shock. The duration and severity of this dysfunction have a prognostic impact by being associated with organ failure and mortality. Our study purposes to demonstrate the feasibility of optical coherence tomography angiography (OCTA) to improve assessment of microcirculatory dysfunction by showing that retinal and choroidal microcirculatory changes with prognostic impact are present during septic shock. Primary objective: To characterize the alterations of retinal and choroidal microcirculation in septic shock. We will test the hypothesis that retinal and/or choroidal microcirculation shows dysfunctional changes (lower vascular density, lower percentage of perfused small vessel, lower blood flow index and higher vascular heterogeneity) in septic shock patients. Secondary objective: To test the prognostic value of retinal and choroidal microcirculatory dysfunction in septic shock. We will test the hypothesis that higher magnitude and persistence of retinal and/or choroidal microcirculatory dysfunction beyond the successful macro-hemodynamic resuscitation are independent predictors of organ failure and mortality in septic shock patients. Study type: Two sequential observational studies. Study design: A cross-sectional case-control study followed by a prospective cohort study with a 90-days longitudinal follow-up period. Study population: 165 septic shock patients and 30 healthy controls. Study duration: 90 days from enrolment to final follow-up assessment. One to two years of enrolment.