When is Extracorporeal Carbon Dioxide Removal (ECCO2R) initiated?

When to Initiate Extracorporeal Carbon Dioxide Removal (ECCO2R)

ECCO2R should be initiated in patients with acute respiratory failure when conventional ventilation strategies fail to maintain acceptable gas exchange, specifically when there is persistent hypercapnia with respiratory acidosis (pH < 7.25) despite optimized ventilatory support. 1, 2

Indications for ECCO2R Initiation

In Acute Respiratory Distress Syndrome (ARDS)

• ECCO2R should be initiated when attempting to implement ultra-protective lung ventilation strategies (tidal volumes 3-4 ml/kg PBW) and the following criteria are met:
  • Driving pressure ≥14 cmH2O 3
  • Plateau pressure ≥25 cmH2O 3
  • Persistent respiratory acidosis (pH < 7.25) despite optimized ventilator settings 4
  • PaCO2 >60 mmHg despite conventional ventilation strategies 4

In Acute Exacerbations of COPD (ae-COPD)

• ECCO2R should be initiated when patients show signs of non-invasive ventilation (NIV) failure: 3, 5
  • No decrease in PaCO2 despite optimized NIV 3
  • No decrease in respiratory rate on NIV 3
  • Persistent respiratory acidosis (pH < 7.25) 5
  • Intolerance to NIV despite optimization 5

In Patients Already on Invasive Mechanical Ventilation

• ECCO2R should be considered when: 1, 6
  • Patients fail weaning attempts due to hypercapnia 5
  • Ultra-protective ventilation is needed but results in unacceptable hypercapnia 4
  • There is a need to reduce ventilator-induced lung injury in severe cases 1

Physiological Targets for ECCO2R Initiation

Blood Gas Parameters

• pH < 7.25 with rising PaCO2 despite optimized conventional therapy 2, 4
• PaCO2 > 60 mmHg with associated respiratory acidosis 4

Ventilatory Parameters

• Inability to maintain protective ventilation (tidal volume ≤6 ml/kg PBW) without causing respiratory acidosis 4
• Need for ultra-protective ventilation (3-4 ml/kg PBW) in severe ARDS 1, 4
• High driving pressures (≥14 cmH2O) despite optimized PEEP 3

Contraindications and Cautions

• ECCO2R should not be initiated in patients with:
  • Severe coagulopathy or active bleeding 6
  • Hemodynamic instability requiring high-dose vasopressors 3
  • Terminal illness with poor prognosis 2

Technical Considerations

• Venovenous ECCO2R is the preferred approach over arteriovenous systems due to fewer complications 7
• Blood flow rates of 430-450 ml/min can remove 60-80 ml CO2 per minute (20-30% of total CO2 production) 7
• For severe hypercapnic respiratory failure (pH ≤ 7.1), higher blood flow rates around 1000 ml/min may be required 7

Treatment Targets After ECCO2R Initiation

For ARDS Patients

• pH > 7.30 3
• Respiratory rate < 25 breaths/min 3
• Driving pressure < 14 cmH2O 3
• Plateau pressure < 25 cmH2O 3

For COPD Patients

• Patient comfort 3
• pH > 7.30-7.35 3
• Respiratory rate < 20-25 breaths/min 3
• Decrease in PaCO2 by 10-20% 3
• Successful weaning from NIV 3

Institutional Requirements

• ECCO2R should be performed at centers with experience in extracorporeal support techniques 1, 2
• A multidisciplinary team including intensivists, pulmonologists, and respiratory therapists should be involved in decision-making 2

Monitoring During ECCO2R

• Continuous monitoring of arterial blood pressure and respiratory parameters 2
• Regular arterial blood gas analysis (every 4-6 hours initially) 2
• Daily echocardiography to assess cardiac function, especially right ventricular function 2
• Meticulous tracking of fluid balance 2
• Monitoring for complications including bleeding, hemolysis, and catheter-related infections 2, 6

ECCO2R represents an important therapeutic option for patients with severe respiratory failure, but its use should be carefully considered given the potential for complications and the need for specialized expertise in its application 1, 6.