While extracorporeal membrane oxygenation (ECMO) case volume continues to increase [1, 2], management of patients receiving ECMO remains technically challenging [2, 3]. Iatrogenic injury is a potential contributor to complications and poor outcomes [4,5,6,7]. Drainage insufficiency, wherein limited pump preload leads to reduced circuit blood flow, is ubiquitous, yet there is no consensus regarding treatment. We propose a physiology-based algorithmic approach to the management of drainage insufficiency.

Analogous to native cardiac physiology, centrifugal pumps are preload dependent such that ECMO blood flow is compromised when there is a mismatch between venous return into the drainage cannula and the drainage pressures at the cannula ports. This relationship is modeled by the Hagen–Poiseuille equation:

where ΔP is the pressure drop across the cannula, Q is the blood flow rate, η is the blood viscosity, L is the cannula length, and r is the cannula radius.