REN and chronic kidney disease: Patients were excluded due to the following criteria: refusal to participate (n = 44, 36%), use of medications interfering with the renin-angiotensin system (n = 41, 32%), norepinephrine already tapered or administered for more than 6 h (n = 19, 15%), chronic kidney disease (n = 12, 10%), chronic liver disease (n = 1, 1%), pregnancy (n = 1, 1%), absence of lactate measurement (n = 2, 1.6%), presence of extracorporeal circulatory assistance (n = 3, 2%), and death within the first 48 h (n = 5, 4%).