What are the RRT modalities available on ICU and how would you choose between them?
“Renal replacement therapy in ICU can be classified into continuous, intermittent, and hybrid modalities.
* CRRT (CVVH, CVVHD, CVVHDF): uses convection, diffusion or both; ideal for unstable patients; precise solute and fluid control; but labour-intensive and requires anticoagulation.
* IHD: intermittent diffusion-based clearance; rapid K⁺ and toxin removal; less resource-heavy; but poorly tolerated in haemodynamic instability.
* Hybrids: SLED offers solute and fluid clearance over 8–12 hrs with better stability; SCUF provides fluid removal only.
The choice depends on haemodynamics, therapeutic goals, and resources. According to KDIGO (2012) and STARRT-AKI (2020), there is no mortality difference between modalities, so selection should be tailored to the patient. In practice, CRRT is favoured in unstable septic patients.”
