Diuresis increase after positive end-expiratory pressure weaning during acute respiratory distress syndrome

Acute kidney failure is a usual side-effect associated with high positive end-expiratory pressure (PEEP) in Acute Respiratory Distress Syndrome (ARDS). Our purpose is to investigate the increase of the 24-hour urine output normalized by body weight (UO), 48 h after PEEP weaning. The primary objective is to calculate the mean variation of UO. The secondary objective is to investigate the factors associated with UO variation, use of renal replacement therapy (RRT) and mortality. We conducted a monocentric retrospective study in Brest adult medical ICU from January 2015 to December 2023. We included 120 patients who required invasive mechanical ventilation for ARDS. We selected patients with impaired urine output (UO ≤ 1 ml/kg/h) 24 h before PEEP weaning. The primary outcome was the variation of the urine output (UO), 48 h after PEEP weaning. Secondary outcomes were the need for RRT and mortality. Two groups were defined: the high responders (HR) group (n = 55) for a variation of UO > 0.35 mL/kg/h and the poor responders (PR) group (n = 65) for a variation of UO ≤ 0.35 mL/kg/h. 77.5% of the patients had an increase of UO (mean value: 0.46 mL/Kg/h). In a multivariate analysis, the OR for a high response to PEEP weaning were 0.89 (p = 0.0014) for the number of days with AKI KDIGO 3 and 0.93 (p = 0.04) for the number of days of IMV before PEEP weaning. The initiation of RRT was associated with higher doses of norepinephrine (0R = 1.77, p = 0.003 chronic kidney disease (OR = 28, p < 0.001), higher number of days with AKI KDIGO 3 (OR = 1.43, p < 0.001), an increased PEEP duration (OR = 1.09, p = 0.049) while it was inversely associated with COVID-19 ARDS (OR 0.07, p = 0.01). ICU mortality was associated with the initiation of RRT (OR = 3.14, p = 0.02) and age (OR 1,06, p = 0.01). 48-hrs following PEEP weaning during ARDS, UO is significantly increased. A decreased duration of invasive mechanical ventilation before weaning and a decreased total number of days with AKI KDIGO 3 were associated with an increased response to PEEP weaning.