Background: The evaluation and management of fluid balance are key challenges in critical care patients who require renal replacement therapies because cumulative fluid balance is an independent factor that increases morbidity and mortality in different clinical scenarios. Summary: One of the strategies when fluid overload is refractory to diuretics is extracorporeal fluid removal (i.e., net ultrafiltration [UFNET] during kidney replacement therapy). However, problems with UFNET without individualized assessment are cardiovascular events and intradialytic hypotension, events that contribute to decreasing organ perfusion and sympathetic stress. Therefore, we must consider and try to predict the best timing for the start of ultrafiltration and find the point where the patient is most tolerant to ultrafiltration, making a simile to the concept of fluid tolerance. Key Messages: UFNET is a continuous and dynamic process, going through moments of tolerance and intolerance to ultrafiltration; as nephrologists, we must take the necessary measures to move through this period.

We present the case of a patient who suffered from acute respiratory distress syndrome caused by pneumonia associated with COVID-19 and cytokine release syndrome. This patient received a high-volume hemofiltration plus adsorption, solving the hemodynamic deterioration, pulmonary infiltrates, and gas exchange. Our clinical case proposes that the extracorporeal therapies can have a role in the management of severe COVID-19.