Determinants of Doppler-based renal resistive index in patients with septic shock: impact of hemodynamic parameters, acute kidney injury and predisposing factors

Renal resistive index (RI) measurements and sequence of RI measurements. A RI measurement corresponded to the mean of five measures performed on five consecutive pulses at one mean arterial pressure (MAP) level. A sequence of RI measurements included from 2 to 5 RI measurements performed in less than 20 min at, at least, 2 MAP levels (aim of at least 15 mmHg apart, between the two levels). When vasopressors were discontinued, the sequence of RI measurements included only one RI measurement at one MAP leve