Renal Replacement Therapy Modalities

General Principles

• The choice of RRT modality should be primarily determined by hemodynamic stability, with continuous therapies preferred for hemodynamically unstable patients and intermittent hemodialysis reserved for stable patients, while all modalities achieve similar mortality outcomes when appropriately matched to patient status 1

Indications for RRT

• Life-threatening hyperkalemia with ECG changes requires emergent RRT initiation, as recommended by clinical guidelines 2, 3
• Severe metabolic acidosis unresponsive to medical therapy requires RRT initiation, according to clinical guidelines 2, 3
• Uremic complications, including pericarditis, encephalopathy, or bleeding diathesis, are indications for RRT, as stated in clinical guidelines 2, 3
• Refractory fluid overload causing pulmonary edema or respiratory compromise requires RRT initiation, as recommended by clinical guidelines 2, 3
• Severe volume overload that cannot be controlled with diuretics is an indication for RRT, according to the Kidney International journal 1

Intermittent Hemodialysis (HD)

• The American Society of Nephrology recommends HD as the preferred modality for hemodynamically stable patients with AKI or CKD requiring rapid correction of electrolyte abnormalities, particularly severe hyperkalemia 3
• HD is indicated for hemodynamically stable patients with AKI or AKD requiring RRT, as stated in the Kidney International journal 1
• CKD stage G5 requiring maintenance dialysis is an indication for HD, typically 3 times weekly for 3-4 hours, according to the Clinical Nutrition journal 4
• Severe hyperkalemia requiring rapid correction in stable patients is an indication for HD, as it provides faster potassium clearance than continuous modalities 3
• Patients without hemodynamic instability who can tolerate rapid solute and fluid shifts are candidates for HD, as recommended by the Kidney International journal 1

Continuous Renal Replacement Therapy (CRRT)

• The National Kidney Foundation recommends CRRT as the preferred modality for hemodynamically unstable patients requiring vasopressor support, providing superior hemodynamic stability through slower solute shifts and better fluid removal tolerance 1, 2
• Hemodynamic instability requiring vasopressor support is an indication for CRRT, as stated in the Kidney International journal 1, 2
• Severe 3-vessel coronary artery disease with AKI is an indication for CRRT, as it provides superior hemodynamic stability, according to the Praxis Medical Insights journal 2
• Increased intracranial pressure is an indication for CRRT, as it has a lower risk compared to intermittent HD, as recommended by the Kidney International journal 1
• Massive fluid overload requiring gradual, controlled removal is an indication for CRRT, as stated in the Kidney International journal 1
• Hypercatabolic states requiring continuous metabolic control are an indication for CRRT, according to the Praxis Medical Insights journal 2

Peritoneal Dialysis (PD)

• The International Society of Peritoneal Dialysis recommends PD as an acceptable modality in resource-limited settings and for hospitalized patients previously on chronic PD, as stated in the Clinical Nutrition journal 4
• Patients already on chronic ambulatory PD who become hospitalized are candidates for PD, according to the Clinical Nutrition journal 4
• Resource-limited settings where extracorporeal therapies are unavailable are an indication for PD, as recommended by the Clinical Nutrition journal 4
• Hemodynamically stable patients with AKI in select circumstances are candidates for PD, according to the Clinical Nutrition journal 4

Critical Decision Algorithm

• Hemodynamically unstable or on vasopressors should be treated with CRRT, CVVHDF, or SLED, as recommended by the Kidney International journal and the Praxis Medical Insights journal 1, 2
• Hemodynamically stable patients should be treated with intermittent HD, as stated in the Kidney International journal 1
• Severe 3-vessel CAD is an indication for CRRT or SLED preferred over intermittent HD, according to the Praxis Medical Insights journal 2
• Increased intracranial pressure is an indication for CRRT preferred over intermittent HD, as recommended by the Kidney International journal 1
• Severe hyperkalemia requiring rapid correction in stable patient is an indication for intermittent HD, according to the Praxis Medical Insights journal 3
• Multiple organ failure (≥3 organs) is an indication for consideration of CVVHDF, as stated in the Praxis Medical Insights journal 2
• APACHE III >103 is an indication for consideration of CVVHDF over HD, according to the Praxis Medical Insights journal 2
• Limited CRRT resources or expertise is an indication for SLED as an acceptable alternative, as recommended by the Clinical Nutrition journal 4
• Severely resource-limited setting is an indication for PD as a consideration, according to the Clinical Nutrition journal 4
• Transition from CRRT to intermittent HD should occur when vasopressor support is discontinued, hemodynamic stability is achieved, and fluid balance is controlled, as recommended by the Kidney International journal and the Praxis Medical Insights journal 1, 3