This document discusses different modalities for treating acute kidney injury (AKI) in critically ill patients, including continuous renal replacement therapy (CRRT) and intermittent hemodialysis. It provides pros and cons of each modality and factors to consider in determining the optimal treatment for an individual patient. While CRRT allows for more gradual fluid removal and hemodynamic stability, clearance is better with intermittent therapies. The document concludes that hemodynamic stability is the main determinant of treatment choice and clearance is optimized through combination of diffusion and convection methods.