Extracorporeal Blood Oxygenation and Ozonation Procedures
Critical Distinction: ECMO is Evidence-Based; Ozonation is Not
ECMO (extracorporeal membrane oxygenation) is a legitimate, guideline-supported rescue therapy for severe cardiorespiratory failure at experienced centers, while extracorporeal blood ozonation has no established role in evidence-based critical care medicine. 1, 2
ECMO: Established Indications and Requirements
Primary Indications for VV-ECMO (Respiratory Support Only)
VV-ECMO should be initiated for severe acute respiratory failure when PaO₂/FiO₂ < 80 mmHg for at least 3 hours despite optimal ventilation strategies, or when plateau pressure > 28 cmH₂O for ≥6 hours despite lung-protective ventilation. 2
Additional respiratory indications include:
- PaO₂/FiO₂ < 100 for ≥6 hours despite optimization of conventional treatments 2
- Evidence of right ventricular overload with pulmonary artery systolic pressure > 40 mmHg and acute cor pulmonale on echocardiography 2
- pH < 7.25 for at least 3 hours due to hypercapnia 3
Critical timing consideration: VV-ECMO should be initiated within 7 days of respiratory failure onset for optimal outcomes, before irreversible end-organ damage occurs. 2 Prolonged mechanical ventilation (>9.6 days) before ECMO is associated with significantly worse outcomes. 2
Primary Indications for VA-ECMO (Combined Cardiopulmonary Support)
VA-ECMO is indicated for cardiogenic shock with very low cardiac output and reduced LV ejection fraction confirmed by echocardiography, requiring significant inotropic support and/or norepinephrine at dosages >0.5 µg/kg/min. 2
Additional cardiac indications include:
- Refractory ventricular arrhythmias unresponsive to conventional therapy 4
- Active cardiopulmonary resuscitation for cardiac arrest 4
- Acute or decompensated right heart failure 4
The key decision point: Assess cardiac function via echocardiography—if the heart is functioning adequately, use VV-ECMO; if combined cardiopulmonary failure exists, use VA-ECMO. 2
Absolute Institutional Requirements
ECMO must only be performed at centers with a minimum annual volume of 20-25 ECMO cases per year, with at least 12 cases specifically for acute respiratory failure. 1, 2 Centers with higher volumes demonstrate significantly better outcomes than lower-volume centers. 2
Mandatory Infrastructure Requirements
A 24/7 multidisciplinary ECMO team must be available, including intensivists, perfusionists, surgeons, specialized nursing staff, and an ECMO program director overseeing operations, training, and quality improvement. 2, 5
Essential physical requirements include:
- Wet-primed ECMO circuit available for immediate deployment 24/7 5
- Uninterrupted Power System (UPS) supporting all equipment for minimum 45 minutes 1, 5
- Backup components for all circuit elements immediately accessible at bedside 5
- Doppler echocardiography machines with trained physicians 5
- Nurse-to-patient ratio of 1:1 to maximum 1:2 2, 5
Mobile ECMO teams should be available 24/7 to retrieve patients from referring hospitals, with experienced personnel trained in critical care transport, cannula insertion, and circuit management. 1, 2
Contraindications
Absolute contraindications to ECMO include contraindications to anticoagulation, as systemic anticoagulation is mandatory for circuit function. 2
Relative contraindications requiring careful consideration:
- Advanced age with multiple comorbidities (young age with fewer comorbidities is favorable) 2
- Irreversible underlying disease process 2
- Prolonged mechanical ventilation >9.6 days before ECMO consideration 2
Critical Complications and Monitoring
Bleeding and Thrombotic Complications
Recent data demonstrates that 42% of VV-ECMO patients experience thrombotic events, 37% experience bleeding events, and 21% experience both complications despite anticoagulation. 2, 5 VA-ECMO carries even higher bleeding risk, with 75.3% experiencing bleeding complications. 2
Almost all ECMO patients develop acquired von Willebrand syndrome (AVWS) within hours of device implantation, contributing significantly to bleeding risk. 2, 6
Neurological Monitoring for VA-ECMO
VA-ECMO carries a 19% acute brain injury risk, requiring protocolized neurological monitoring immediately upon initiation. 5
Mandatory monitoring includes:
- Continuous cerebral oximetry to detect acute brain injury early 5
- Arterial blood gases from right radial arterial line to represent cerebral oxygenation 5
- Intermittent EEG and somatosensory evoked potentials in comatose patients 5
Monitor for differential hypoxemia in peripheral VA-ECMO, where poorly-oxygenated blood from the failing native heart may perfuse the upper body and brain. 5 When detected, immediately increase ECMO flow to move the mixing point proximally. 5
Left Ventricular Overload in VA-ECMO
Left ventricular overload is a specific complication of VA-ECMO that may require additional mechanical unloading devices (IABP or Impella) to reduce cardiac dilation and pulmonary edema. 2, 6
Hemodynamic Management Targets
Target initial ECMO flow of 3-4 L/min immediately post-cannulation, gradually increasing as tolerated, with arteriovenous oxygen difference between 3-5 cc O₂/100ml blood as the most reliable flow parameter. 5
Additional targets include:
- Mean arterial pressure >70 mmHg to ensure adequate cerebral and end-organ perfusion 5
- PaO₂ >70 mmHg to prevent hypoxemia-associated acute brain injury, while avoiding severe arterial hyperoxia (PaO₂ >300 mmHg) 5
Ozonation Therapy: No Evidence-Based Role
Extracorporeal blood ozonation has no established indications in evidence-based critical care medicine and is not mentioned in any major critical care society guidelines. The provided evidence contains no support for ozonation procedures in the management of critically ill patients with cardiorespiratory failure. ECMO remains the only evidence-supported extracorporeal blood treatment for severe respiratory or cardiac failure. 1, 2
Common Pitfalls to Avoid
- Do not delay ECMO referral beyond 7 days of respiratory failure onset or after >9.6 days of mechanical ventilation, as outcomes worsen significantly. 2
- Do not attempt ECMO at low-volume centers (<20 cases/year), as the learning curve requires at least 20 cases for competence. 1, 2
- Do not overlook the need for optimization of conventional treatments (lung-protective ventilation, prone positioning) before considering ECMO. 2
- Do not fail to assess cardiac function via echocardiography before selecting VV versus VA-ECMO configuration. 2
- Do not underestimate bleeding risk—maintain vigilant monitoring and have protocols for managing both thrombotic and hemorrhagic complications. 2, 5