Abstract 345: Effects of Cannula Size in Venoarterial Extracorporeal Membrane Oxygenation
Background: The degree of circulatory support that patients treated with veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) receive is limited by the size of the arterial cannula. However, the use of ECMO is associated with significant morbidity related to complications of cannulation, including limb ischemia and need for blood transfusion. We investigated the relationship between cannula size and clinical outcomes as well as transfusion needs in patients treated with VA ECMO.
Methods: We performed a retrospective review of all patients treated with percutaneous VA ECMO at the University of Chicago Medical Center from January to December 2012. Baseline characteristics, size of arterial cannula, blood transfusions, and outcomes were recorded. Fisher’s exact test was used to compare the association between survivor status and cannula size (15 vs greater than 15 Fr). Association between cannula size and transfusion of packed red blood cells over the first 24 hours of treatment was determined using a quadratic regression model.
Results: Percutaneous VA ECMO was initiated in 15 patients. 7 patients were alive at 30 days after ECMO initiation. The use of a smaller cannula was significantly associated with survival (P < 0.01) There was an association between the size of the arterial cannula and blood transfusion needs (P <0.01). Two patients experienced significant hemorrhage related to cannulation. Other major complications included HIT (1) and DIC (1). Limb ischemia was not seen as all patients underwent anterograde cannulation at time of ECMO initiation.
Conclusions: Use of smaller arterial cannulae in VA ECMO was associated with increased survival and there was a correlation between cannula size and need for transfusion. Smaller cannulae result in lower flow rates, but also in reduced vascular complications. Further study is warranted to determine the balance between providing circulatory support and reducing complications in patients treated with VA ECMO.
- © 2013 by American Heart Association, Inc.