University of Virginia Nutrition
This month’s article was a little different from our usual fare because it delved into the world of neonatal nutrition support. We rarely encounter adult patients receiving extracorporeal membrane oxygenation (ECMO), but had a case recently and questions arose about the appropriateness of iv lipid emulsions in patients receiving ECMO.
Buck ML, et al. Comparison of methods for intravenous infusion of fat emulsion during extracorporeal membrane oxygenation . Pharmacotherapy 2005;25(11):1536-1540.
This was a prospective, randomized, open-label trial of nine neonates who required parenteral nutrition while receiving ECMO. Five patients received the lipid-containing parenteral nutrition through the ECMO circuit, and 4 patients received the PN through a separate iv access. The ECMO circuit and blood samples were evaluated for phase separation, layering of the emulsion from blood, agglutination, and blood clots.
Major Results reported by authors:
The investigators reported that there were no instances of phase separation in either group. Layering-out of the emulsion, and agglutination in the tubing occurred in three of the five patients when the lipid emulsion was administered through the ECMO circuit, but occurred in only one of the four patients who received iv lipids via separate iv catheter. One patient in the ECMO-infusion group developed blood clots that necessitated 2 circuit changes, and two patients in the iv-infusion group each required circuit changes from blood clots.
Authors Conclusions :
Both methods of iv lipid infusion were associated with layering out, agglutination, and clot formation. These effects occurred more frequently with administration into the ECMO circuit. This may result in disruption of normal ECMO blood flow and impaired delivery of calories. Fat emulsion should therefore be administered through separate intravenous access during ECMO whenever possible.
This study has a number of limitations, including the lack of a control group that did not receive lipid emulsion, and a very small “N”. The very small number of patients makes it difficult to develop any strong conclusions from this study. Our inquiry into this topic was spurred by the question whether it was appropriate to provide lipids with TPN to an adult patient receiving ECMO. Adults who require TPN already have a central line, so the issue of TPN through the ECMO circuit was less critical to us. There was no evidence from this small study to suggest that there were any adverse clinical effects to the neonates, or compromise to the ECMO device, from infusing iv lipid emulsion with TPN through a central line.
Take home message:
A comparison of patients receiving enteral feeding versus TPN with lipids while receiving ECMO would be helpful to determine if the use of iv lipid emulsion actually increases the incidence of layering out, agglutination, or clot formation during ECMO.
1. Check out the latest Practical Gastroenterology article at:www.uvadigestivehealth.org
Scroll down to GI Nutrition within the on the far left column and
click on link
Then scroll down to box with links nutrition site
Nutrition Articles in Practical Gastroenterology is in the left column.
The February 2006 citation is:
Ukleja A. Dumping Syndrome . Practical Gastroenterology 2006;XXX(2):32.
2) Check out this website:
It was developed to help residents during their critical care rotation in the surgical ICU at the University of Pennsylvania , and has some great information – everything from understanding what Critical Care is, to how CVVHD works.
Joe Krenitsky MS, RD
Carol Parrish RD, MS
PS – Please feel free to forward this on to friends and colleagues.