Extracorporeal
membrane oxygenation (ECMO) is an effective therapy for patients with
reversible cardiac and/or respiratory failure. AKI often occurs in patients supported with ECMO;
it frequently evolves into chronic kidney damage or end-stage renal disease and
is associated with a reported 4-fold increase in mortality rate. What are the
mechanisms of injury of AKI with ECMO?
This table below summarizes what
might be the potential causes.
|
Patient-related variables
|
|
|
Pretreatment factors
|
Hypoperfusion, loss of
autoregulation Hypoxia
|
|
Nephrotoxic drugs Systemic
inflammation
|
|
|
|
|
|
ECMO-related variables
|
|
|
Hemodynamic factors
|
Blood flow alterations
|
|
Hormonal factors
|
Renin-angiotensin-aldosterone
dysregulation ANP downregulation
|
|
ECMO-related
|
Blood shear stress
|
|
Systemic inflammation
|
Exposure to a non-self membrane
Blood/air interface
|
|
Organ crosstalk
|
Cardio-renal syndrome
|
|
Circuit-related factors
|
Hypermyoglobinemia
|
|
Embolism
|
|
|
Hemolysis
 |
|
Hemolysis is an interesting cause. This is an image
of a patient getting CRRT on ECMO. CRRT
was on a zero K bath and high clearance rates. Within hours of starting CRRT, effluent
bags of the CRRT turn red. Despite being on max CRRT, patient’s potassium
rose to 9mmol/L. This is hemolysis and can be reported in 18% of cases with
ECMO. Rhabdomyolysis can also be noted
in some cases. Checking a free Hgb and effluent myoglobin can aid diagnosis for
both entities. In addition, classic markers for hemolysis such as LDH,
haptoglobin, anemia and so forth should be checked regularly.
