What are the criteria for managing bleeding in a patient on Continuous Renal Replacement Therapy (CRRT)?

Bleeding Management in CRRT

For patients on CRRT who develop active major bleeding, immediately withhold anticoagulation and provide supportive care including transfusion and surgical intervention to control the bleeding source. 1

Initial Assessment of Bleeding

When bleeding occurs during CRRT, perform a systematic evaluation:

• Identify the bleeding source, severity, and whether it is amenable to intervention 1
• Classify bleeding as major (life-threatening, critical site, or not amenable to intervention) versus minor (e.g., minor epistaxis without hemodynamic consequences) 1
• Assess for reversible causes and provide appropriate supportive treatments including red blood cell transfusion when indicated 1

Management Algorithm Based on Bleeding Severity

Major or Life-Threatening Bleeding

Immediately discontinue all anticoagulation 1

For patients with acute or subacute thrombosis (high risk of recurrent VTE):

• Consider IVC filter insertion to prevent pulmonary embolism while anticoagulation is held 1
• Resume anticoagulation once bleeding resolves 1
• Remove retrievable IVC filter after anticoagulation is restarted 1

For patients with chronic thrombosis (low risk of recurrent VTE):

• Do not insert IVC filter 1

Minor Bleeding

Most patients with minor bleeding can continue anticoagulation with close monitoring, as these episodes typically occur without significant physiologic consequences 1

Anticoagulation Strategy After Bleeding Resolves

Once bleeding is controlled, select anticoagulation based on ongoing bleeding risk:

For Patients with Persistent High Bleeding Risk

Regional citrate anticoagulation is the preferred strategy over heparin or no anticoagulation when citrate is not contraindicated 1, 2, 3

Avoid citrate in patients with:

• Severe liver dysfunction (impaired citrate metabolism) 2
• Risk of citrate accumulation 2

If citrate is contraindicated, run CRRT without anticoagulation rather than using heparin 2, 3

For Patients with Resolved Bleeding Risk

Use regional citrate anticoagulation as first-line when no contraindications exist 1, 2

Alternative options include:

• Unfractionated heparin or low-molecular-weight heparin if citrate contraindicated 1
• Target aPTT 1-1.4 times normal for unfractionated heparin 4
• Target anti-Xa 0.25-0.35 IU/L for low-molecular-weight heparin 4

Special Considerations

Heparin-Induced Thrombocytopenia (HIT)

All heparin must be stopped immediately 1, 2, 3

Use direct thrombin inhibitors (argatroban) or Factor Xa inhibitors (danaparoid, fondaparinux) 1, 2, 3

For HIT patients without severe liver failure, argatroban is preferred over other alternatives 1, 2

Intracranial Bleeding

Decision to restart anticoagulation requires collaboration with neurology or neurosurgery given the high risk of catastrophic rebleeding 1

Monitoring Requirements During CRRT

When using regional citrate anticoagulation:

• Monitor systemic acid-base balance regularly, especially in high-risk patients 2
• Track serum sodium levels to prevent hypernatremia 2
• Follow systemic ionized calcium levels in patients with liver dysfunction 2
• Monitor for electrolyte abnormalities including hypophosphatemia, hypokalemia, and hypomagnesemia 2

When using heparin anticoagulation:

• Measure activated clotting times (ACT) or systemic aPTT to minimize bleeding risk 5
• Monitor platelet counts routinely to detect HIT 5, 3

Common Pitfalls to Avoid

• Do not use regional heparinization in patients with increased bleeding risk 1, 3
• Implement strict protocols for citrate anticoagulation with adequate staff education to prevent prescription errors 2
• Do not rely solely on conventional coagulation parameters to predict filter failure or guide anticoagulation decisions 6
• Avoid subclavian vein access when possible due to thrombosis and stenosis risk 1