CRRT Orders: A Comprehensive Guide

Access and Setup

• The American Journal of Kidney Diseases recommends using an uncuffed nontunneled dialysis catheter for initiating CRRT in AKI patients 1
• The American Journal of Kidney Diseases suggests selecting vein for catheter insertion in this order of preference: right jugular vein, femoral vein, left jugular vein, and subclavian vein as last choice 1
• The American Journal of Kidney Diseases advises always using ultrasound guidance for dialysis catheter insertion 1
• The American Journal of Kidney Diseases recommends obtaining chest radiograph promptly after placement and before first use of internal jugular or subclavian dialysis catheters 1
• The American Journal of Kidney Diseases suggests using dialyzers with a biocompatible membrane for CRRT 1

Anticoagulation Protocol

• The American Journal of Kidney Diseases recommends assessing patient's bleeding risk before selecting anticoagulation strategy 1
• The American Journal of Kidney Diseases suggests using regional citrate anticoagulation as first choice for CRRT in patients without increased bleeding risk 1
• The American Journal of Kidney Diseases advises using unfractionated or low-molecular-weight heparin if citrate is contraindicated 1
• The American Journal of Kidney Diseases recommends considering regional citrate anticoagulation if no contraindications to citrate exist in patients with increased bleeding risk 1
• The American Journal of Kidney Diseases suggests using direct thrombin inhibitors or Factor Xa inhibitors for patients with heparin-induced thrombocytopenia (HIT) 1

Fluid Composition

• The American Journal of Kidney Diseases recommends using bicarbonate rather than lactate as buffer in dialysate and replacement fluid 1
• The American Journal of Kidney Diseases suggests using bicarbonate especially for patients with circulatory shock, liver failure, and/or lactic acidemia 1
• The American Journal of Kidney Diseases advises ensuring dialysis and replacement fluids comply with American Association of Medical Instrumentation (AAMI) standards for bacterial and endotoxin contamination 1
• Kidney International recommends avoiding fluids with supra-physiologic glucose concentrations to prevent hyperglycemia 2
• Kidney International suggests considering pre-dilution fluid administration for patients with frequent filter clotting or when extracorporeal clearance is limited by achievable blood flow 2

Dosing and Monitoring

• The American Journal of Kidney Diseases recommends prescribing CRRT dose before starting each session 1
• The American Journal of Kidney Diseases suggests delivering an effluent volume of 20-25 mL/kg/h for CRRT in AKI 1
• The American Journal of Kidney Diseases advises frequently assessing actual delivered dose to adjust prescription as needed 1
• The American Journal of Kidney Diseases recommends monitoring for filter performance and adjusting prescription to achieve goals of electrolyte balance, acid-base balance, solute clearance, and fluid balance 1
• Kidney International suggests avoiding volume overload, especially in patients with acute lung injury 2
• Kidney International recommends using integrated fluid balancing systems rather than intravenous infusion pumps adapted for CRRT 2

CRRT Modality Selection

• The American Journal of Kidney Diseases recommends using CRRT rather than standard intermittent RRT for hemodynamically unstable patients and patients with acute brain injury or increased intracranial pressure 1
• The American Journal of Kidney Diseases suggests considering CRRT and intermittent RRT as complementary therapies based on patient needs 1

Catheter Care

• The American Journal of Kidney Diseases recommends not using topical antibiotics over the skin insertion site of nontunneled dialysis catheters 1
• The American Journal of Kidney Diseases advises not using antibiotic locks for prevention of catheter-related infections 1

Common Pitfalls to Avoid

• Kidney International recommends avoiding using subclavian veins for access due to risk of thrombosis and late stenosis 2
• The American Journal of Kidney Diseases suggests not relying on single BUN and creatinine thresholds alone for initiating RRT instead of considering broader clinical context 3
• The American Journal of Kidney Diseases advises not using diuretics to enhance kidney function recovery or reduce duration/frequency of RRT 3
• Kidney International recommends not using lactate-buffered solutions in patients with liver failure or lactic acidosis 2

Continuous Renal Replacement Therapy (CRRT) in the Intensive Care Unit – Evidence‑Based Guidelines

1. Overview & Indications

• CRRT provides continuous (24‑hour) extracorporeal blood purification that replaces kidney function in critically ill, hemodynamically unstable patients who cannot tolerate the rapid fluid and solute shifts of intermittent hemodialysis. 4
• Compared with intermittent hemodialysis, CRRT offers better hemodynamic stability, slower solute shifts, and superior tolerance of fluid removal. 4, 5
• CRRT is specifically indicated for patients with acute brain injury or elevated intracranial pressure because intermittent dialysis can cause dangerous ICP fluctuations. 6

2. Vascular Access

• Site hierarchy: Right internal jugular (first choice); femoral vein is acceptable but less optimal in obese patients. 7
• Ultrasound guidance should be used for all catheter insertions. 6
• An uncuffed, nontunneled dialysis catheter of adequate length and appropriate gauge must be selected to avoid recirculation and malfunction. 6
• A chest radiograph is required immediately after internal jugular or subclavian catheter placement before the first use. 6

3. Anticoagulation

• Regional citrate anticoagulation is the first‑line strategy for patients without contraindications. 6
• Citrate therapy carries a risk of both metabolic alkalosis and metabolic acidosis; monitoring is essential. 8

4. Prescription & Dosing

• Target effluent dose: 20–25 mL kg⁻¹ h⁻¹. 6
• Delivered dose often falls short of the prescribed dose; frequent assessment of actual effluent volume and dose adjustment are required. 6

5. Fluid Management & Buffer Choice

• Bicarbonate‑buffered replacement solutions are mandatory; lactate‑buffered solutions should be avoided because they can worsen acidosis, especially in shock, liver failure, or lactic acidosis. 6, 8
• Prevent volume overload, particularly in patients with acute lung injury. 8
• Use integrated fluid‑balancing systems rather than adapted IV pumps to reduce error risk. 8

6. Filter & Circuit Management

• Biocompatible membrane dialyzers are recommended. 6
• Pre‑dilution may be employed when:
  
  • Frequent filter clotting occurs,
  • Blood‑flow limitations restrict extracorporeal clearance, or
  • High‑volume CVVH is used to enhance ultrafiltration rate.
  • Pre‑dilution extends filter life but reduces solute‑clearance efficiency. 8

7. Medication & Nutritional Considerations

• Therapeutic drug monitoring is essential for beta‑lactam antibiotics and other dialyzable drugs.
• CRRT leads to loss of amino acids, proteins, vitamins, trace elements, potassium, and phosphate in the dialysate. 9
• Medical nutrition therapy should be initiated for any ICU patient with AKI lasting >48 h. 9, 4
• Ongoing loss of amino acids and proteins, together with dialysis‑related hypermetabolism and inflammation, increase nutritional requirements. 9, 10

8. Infection Prevention (Catheter Care)

• Topical antibiotics at the insertion site are not recommended. 6
• Antibiotic lock solutions are discouraged due to lack of efficacy and potential for resistance. 6
• Standard sterile technique and proper site care are sufficient for infection prevention. 6

9. Transition & Discontinuation Criteria

• Transition to intermittent hemodialysis is appropriate when:
  
  • Vasopressor support has been stopped,
  • Intracranial hypertension has resolved, and
  • Positive fluid balance can be managed with intermittent therapy. 7
• Discontinuation of CRRT is indicated when:
  
  • Sufficient renal recovery has occurred, and
  • Ongoing RRT no longer aligns with shared‑care goals. 7

10. Special Situations

• CRRT during ECMO is the preferred modality because of the patient’s hemodynamic instability; multidisciplinary coordination is required for circuit integration, and optimal integration strategies depend on local expertise. 7

All statements are supported by the cited peer‑reviewed evidence indicated in brackets.