The Kigali modification of the berlin definition: a new epidemiological tool for ARDS?

We read with great interest the paper by Riviello et al. (1) in which they used an “adjustment” of the Berlin definition, the so called “Kigali modification”, to estimate the incidence and outcomes of acute respiratory distress syndrome (ARDS) at a Rwandan referral hospital by the enrollment of every adult patient admitted for hypoxia (saturation less than 90%) throughout a 6-week period. According to the Kigali modification, ARDS was defined without the need of positive end-expiratory pressure, with the presence of bilateral opacities at chest radiograph or lung ultrasound and hypoxia was defined with a cutoff of SpO2/FIO2 less than or equal to 315. The study by Riviello et al. (1) interestingly points at a limitation of the Berlin definition, that is the real difficulties in a correct estimation of ARDS incidence in developing countries, taking into accounts differences in resource availability and especially in capacity for positive pressure ventilation and ICU beds.