6, 8, 9, 10
Supports setting flow to establish adequate delivery, confirming with venous saturation and lactate, then reducing flow as physiology allows - rather than leaving flow where it was first set. Reconciles with the 0.6 ratio rule, which is the no-native-lung worst case rather than a target.
Targeting raw extracorporeal blood flow rate
DOI 10.1164/rccm.202403-0654ED
Titrating extracorporeal support against physiological targets
An editorial, not a trial. No randomised comparison of titration targets on VV ECMO exists. The flow-ratio figures describe the population discussed, not a general prescription.
Editorial arguing against targeting raw extracorporeal blood flow rate and for titrating support against mixed venous oxygen saturation and its physiological consequences, including right ventricular workload and the pulmonary circulation. Priority target is the oxygen delivery to consumption ratio: maintain DO2:VO2 of at least the critical threshold of 2:1, with DO2 close to or above half of normal, around 300 mL/min/m2. In the data discussed, the mean extracorporeal flow to cardiac output ratio ranged from 20% to 44% across low and high venous saturation targets. Targeting higher SvO2 (70-90%) improved haemodynamic outcomes, independent of ventilation or vasopressor adjustment.
Adults on venovenous ECMO