CVVH Management Guidelines for Adult ICU Patients with Acute Kidney Injury and Fluid Overload
Vascular Access
Prescription Parameters
Replacement Fluid Composition
Anticoagulation Strategy
Fluid Removal Strategy
Monitoring Requirements
Temperature Management
Common Pitfalls to Avoid
Transition Criteria to Intermittent Hemodialysis
Special Considerations for Patients on ECMO
Indications for CRRT in CVICU Patients with Acute Kidney Injury
Primary Indications for CRRT in CVICU
- The American College of Cardiology and Kidney International recommend CRRT for hemodynamically unstable patients with AKI in the CVICU setting, as it provides superior hemodynamic tolerance compared to intermittent modalities 4, 5
- CRRT is recommended over intermittent hemodialysis for patients with acute brain injury or increased intracranial pressure, due to lower risk of cerebral edema and intracranial pressure fluctuations 4, 6
- CRRT provides better control of fluid balance in critically ill cardiac patients, especially when positive fluid balance cannot be managed by intermittent hemodialysis 5, 6
- The Kidney International guideline suggests CRRT should be initiated when metabolic and fluid demands exceed the kidney's capacity, particularly for management of severe acid-base and electrolyte disturbances 5
Specific CVICU Considerations
- CRRT is particularly important in ECMO patients for preventing and managing fluid overload, which is critical for optimal ECMO function 7
- For patients requiring extracorporeal life support (ECLS) such as ECMO or ventricular assist devices, CRRT should be integrated based on institutional expertise and available technology 6, 7
Technical Aspects of CRRT Implementation
Access and Setup
- The American Journal of Kidney Diseases recommends using an uncuffed nontunneled dialysis catheter for initiating CRRT 4
- Preferred vascular access sites (in order): right jugular vein, femoral vein, left jugular vein, and subclavian vein as last choice 4, 8
- Always use ultrasound guidance for catheter insertion and obtain chest radiograph before first use of internal jugular or subclavian catheters 4
Anticoagulation Protocol
- For patients without increased bleeding risk, regional citrate anticoagulation is recommended 4, 8
- For patients with heparin-induced thrombocytopenia, use direct thrombin inhibitors (argatroban) or Factor Xa inhibitors 4
- Avoid regional heparinization in patients with increased bleeding risk 4
Dosing and Monitoring
- Deliver an effluent volume of 20-25 mL/kg/h for CRRT in AKI 4, 5
- Use bicarbonate rather than lactate as buffer in dialysate and replacement fluid, especially for patients with circulatory shock, liver failure, or lactic acidemia 4, 8
When to Transition from CRRT to Intermittent Modalities
- Consider transitioning from CRRT to intermittent hemodialysis when vasopressor support has been discontinued, hemodynamic stability has been achieved, intracranial hypertension has resolved, and positive fluid balance can be adequately controlled by intermittent hemodialysis 5, 6, 7
Pitfalls to Avoid
- Don't rely solely on single BUN and creatinine thresholds for initiating CRRT; consider the broader clinical context 8
- Avoid using subclavian veins for access due to risk of thrombosis and stenosis 8
- Don't use lactate-buffered solutions in patients with liver failure or lactic acidosis 4, 8