Impact of early mean arterial pressure level on severe acute kidney injury occurrence after out-of-hospital cardiac arrest.

Background: The optimal early mean arterial pressure (MAP) level in terms of renal function remains to be established in patients with out-of-hospital cardiac arrest (OHCA). We aimed to evaluate the association between early MAP level and severe acute kidney injury (AKI) occurrence in patients with OHCA.

Results: In 568 consecutive patients, the percentage time spent below a predefined MAP threshold and the corresponding area below threshold (ABT) were calculated from continuous MAP measurement. Both MAP-derived variables were calculated for different MAP thresholds (65, 75 and 85 mmHg) and time periods (the first 6 and 12 after ICU admission). 274 (48%) patients developed severe AKI defined as stage 3 of KDIGO. Both ABT and percentage time were independently associated with severe AKI, regardless of the MAP threshold and time period considered. Highest adjusted odds ratios for developing severe AKI were observed while considering the first 6 h period. Within the first 6 h, every 100 mmHg-h increase in ABT under MAP thresholds of 65, 75 and 85 mmHg increased severe AKI risk by 69% (OR = 1.69; 95% CI 1.26-2.26; p < 0.01), 13% (OR = 1.13; 95% CI 1.07-1.20; p < 0.01) and 4% (OR = 1.04; 95% CI 1.02-1.06; p < 0.01), respectively. Every 10% increase in percentage time spent under MAP thresholds of 65, 75 and 85 mmHg increased severe AKI risk by 19% (OR = 1.19; 95% CI 1.06-1.33; p < 0.01), 12% (OR = 1.12; 95% CI 1.04-1.19; p < 0.01) and 8% (OR = 1.08; 95% CI 1.02-1.14; p < 0.01), respectively.

Conclusions: Both severity and duration of early arterial hypotension after ICU admission remained associated with severe AKI occurrence while considering a MAP threshold as high as 85 mmHg after OHCA.