Table 2 Titratable ECMO parameters during weaning and their effects
From: Physiological adaptations during weaning from veno-venous extracorporeal membrane oxygenation
Parameter which can be weaned | Relationship with V’O2ML | Relationship with V’CO2ML | Downsides of weaning in isolation |
|---|---|---|---|
ECBF | Linear relationship if QR is minimal | Linear relationship between 0 and 0.5 L/min Logarithmic relationship between 0.5 and 1 L/min Minimal change > 1 L/min Influenced by membrane lung surface and SGF | Low ECBF flows may increase circuit thrombosis Changes in ECBF will also affect QR |
SGF | Minimal change until almost zero | Decrease V’CO2ML | When SGF is turned to zero V’O2ML ceases suddenly but hypoxic pulmonary vasoconstriction takes minutes to react |
FdO2 | Decrease V’O2ML | No effect | Weaning may alter the respiratory quotient and reduce alveolar oxygen |