Supplementary Material for: Hourly Fluid Balance in Patients Receiving Continuous Renal Replacement Therapy

<b><i>Introduction:</i></b> Little is known about early (first 48 h) hourly and cumulative fluid balance (FB) during continuous renal replacement therapy (CRRT). <b><i>Objectives:</i></b> To study the characteristics and outcome associations of early hourly and cumulative FB. <b><i>Methods:</i></b> We studied FB in CRRT patients (2016–2018). <b><i>Results:</i></b> Among 350 patients, mean hourly FB became negative after 20 CRRT hours, but within 6 CRRT hours in patients with baseline fluid overload. A negative early FB was never achieved in patients receiving vasopressor therapy (<i>p</i> &lt; 0.001). Mortality was 31%. The percentage of hourly negative FB was independently associated with decreased ICU mortality. A time-weighted hourly FB between 18.5 and –33 mL/h was also significantly and independently associated with decreased mortality. <b><i>Conclusions:</i></b> In CRRT patients, an early FB conservative approach is possible, modulated by patient characteristics, and associated with a low mortality. Moreover, avoidance of an early positive FB is associated with decreased mortality.