Continuous Renal Replacement Therapy (CRRT) is a specialized form of dialysis used primarily in critically ill patients who are unable to tolerate the rapid fluid and solute shifts associated with conventional hemodialysis. Unlike intermittent treatments, CRRT runs continuously over 24 hours, providing slow and steady removal of waste products, electrolytes, and excess fluid. This makes it highly suitable for patients with severe hemodynamic instability, sepsis, multi-organ dysfunction, or shock.
CRRT can be delivered in several modes, including CVVH (hemofiltration), CVVHD (hemodialysis), CVVHDF (hemodiafiltration), and SCUF (slow continuous ultrafiltration). Each mode allows individualized control over fluid removal and solute clearance. The continuous nature of therapy helps maintain stable blood pressure, prevents sudden biochemical fluctuations, and supports critically ill patients requiring precise fluid balance.
One of the biggest advantages of CRRT is its ability to manage fluid overload while maintaining hemodynamic stability. This is especially important in patients with heart failure, liver disease, or sepsis. CRRT also allows continuous removal of inflammatory mediators, potentially improving outcomes in septic shock. It provides superior control over electrolytes such as potassium, sodium, and bicarbonate.
However, CRRT is resource-intensive. It requires specialized machines, constant monitoring, trained ICU nurses, and anticoagulation to prevent clotting in the circuit. The risk of bleeding increases due to anticoagulant use. Filter clotting, machine alarms, and interruptions can reduce therapy effectiveness. Additionally, CRRT is more expensive than intermittent modalities.
Despite its limitations, CRRT remains the gold standard for renal support in critically ill, unstable patients. Its ability to provide controlled and continuous therapy makes it essential in modern ICUs.
