Fig. 1

Flowchart. ^aChronic kidney disease (estimated precritical illness glomerular filtration rate < 60 mL/min/1.73 m²). ^bRenal replacement therapy (RRT) has been already started in the ICU for AKI, or commencing RRT (according to last laboratory values) was likely within the next 6 h or patient underwent regular (chronic) dialyses. ^cPatient has received less than 20 mL/kg i.v. fluids during the last 12 h for shock/hypovolemia or patient has been in the ICU less than 6 h. ^dCardiac arrhythmias affecting blood pressure, increase in norepinephrine need over 0.2 ug/kg/min, need for initiation of inotrope/inodilator within the last 2 h pre-randomization. ^eUrgent indications for commencing RRT for AKI at the moment of randomization were present (based on last blood work): plasma potassium > 6 mmol/L or severe metabolic acidosis (pH < 7.20 and bicarbonate < 12 mmol/L) or evidence of severe respiratory failure (PaO₂/FiO₂ ratio < 200) and clinical perception of volume overload or AKI has continued over 72 h. (Creatinine remains more than twice the normal level/oliguria continued.) ^fCumulative fluid accumulation exceeds 10% of baseline body weight. ^gBilateral infiltrates in chest X-ray. ^hObtaining informed written consent was not possible (i.e., patient or her/his next of kin did not speak Finnish or Swedish), or consent was denied. ^jFor example organ recipients, cardiopulmonary resuscitated patients with temperature control treatment, severe electrolyte disturbances (predominantly hyponatremia), logistic reasons, patients recruited in another study. Patient recruitment was interrupted in 2020 from March to May because of COVID-19 pandemic