School of Medicine and Health Sciences Poster Presentations

The Safety of Hemoconcentration During ECMO

Document Type

Poster

Abstract Category

Clinical Specialties

Keywords

ECMO, Hemoconcentration

Publication Date

Spring 5-1-2019

Abstract

Hemoconcentration is regularly used in the operating room for cardiac surgery patients with a positive fluid balance or impaired renal function. A hemoconcentrator can be safely added to the heart lung machine where blood runs through the 40 micron filter, often with a vacuum applied, to create a high transmembrane pressure forcing cell water and small solutes out of the dialysate port and out of circulation. The access for the hemoconcentrator is connected to a positive pressure port on the circuit distal to the centrifugal or roller pump. The return from the hemoconcentrator is attached to the top of the circuit's reservoir with either no pressure or negative pressure to return the blood. A hemoconcentrator, after priming, can also be attached to an ECMO circuit. Though an ECMO circuit usually does not contain the same safety of an open return reservoir, if adequately primed and de-aired it can be returned to a port pre-pump with minimal risk of air embolus. While used in some institutions, the safety of hemoconcentration during ECMO has not been widely studied. In this study, the last 100 ECMO patients at the George Washington University Hospital were retrospectively reviewed for documented hemoconcentration events. Each hemoconcentration event was then studied closer to examine for amount of fluid removed during hemoconcentration, adverse events during and after hemoconcentration, changes in ECMO flow rates before and after the hemoconcentration event, and chemistry and iStat labs were compared before and after the hemoconcentration event. Once the average pre and post values were calculated, the results were analyzed using a t-test and a Wilcox Rank Sum. After review, 75 hemoconcentration events were identified. Out of these, one adverse event was recorded showing hypotension and decreased ECMO flow rates. The average event removed 1.2 L of dilute fluid. Hemoconcentration was performed in both VA and VV ECMO patients with a wide variety of pathophysiologies. ECMO flow rates, chemistry and iStat labs showed on average no difference. The potential benefits of hemoconcentration during ECMO include the ability to rapidly correct hypervolemia and the ability to maintain hemoconcentration without significant blood transfusion. However, hemoconcentration could result in rapid fluid shifts, electrolyte derangement, and hemodynamic instability in an already unstable patient. This data presented here supports the idea that hemoconcentration when can be safely used during ECMO without significant adverse events. Further and larger studies are needed to better understand the effect of hemoconcentration during ECMO.

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Presented at Research Days 2019.

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The Safety of Hemoconcentration During ECMO

Hemoconcentration is regularly used in the operating room for cardiac surgery patients with a positive fluid balance or impaired renal function. A hemoconcentrator can be safely added to the heart lung machine where blood runs through the 40 micron filter, often with a vacuum applied, to create a high transmembrane pressure forcing cell water and small solutes out of the dialysate port and out of circulation. The access for the hemoconcentrator is connected to a positive pressure port on the circuit distal to the centrifugal or roller pump. The return from the hemoconcentrator is attached to the top of the circuit's reservoir with either no pressure or negative pressure to return the blood. A hemoconcentrator, after priming, can also be attached to an ECMO circuit. Though an ECMO circuit usually does not contain the same safety of an open return reservoir, if adequately primed and de-aired it can be returned to a port pre-pump with minimal risk of air embolus. While used in some institutions, the safety of hemoconcentration during ECMO has not been widely studied. In this study, the last 100 ECMO patients at the George Washington University Hospital were retrospectively reviewed for documented hemoconcentration events. Each hemoconcentration event was then studied closer to examine for amount of fluid removed during hemoconcentration, adverse events during and after hemoconcentration, changes in ECMO flow rates before and after the hemoconcentration event, and chemistry and iStat labs were compared before and after the hemoconcentration event. Once the average pre and post values were calculated, the results were analyzed using a t-test and a Wilcox Rank Sum. After review, 75 hemoconcentration events were identified. Out of these, one adverse event was recorded showing hypotension and decreased ECMO flow rates. The average event removed 1.2 L of dilute fluid. Hemoconcentration was performed in both VA and VV ECMO patients with a wide variety of pathophysiologies. ECMO flow rates, chemistry and iStat labs showed on average no difference. The potential benefits of hemoconcentration during ECMO include the ability to rapidly correct hypervolemia and the ability to maintain hemoconcentration without significant blood transfusion. However, hemoconcentration could result in rapid fluid shifts, electrolyte derangement, and hemodynamic instability in an already unstable patient. This data presented here supports the idea that hemoconcentration when can be safely used during ECMO without significant adverse events. Further and larger studies are needed to better understand the effect of hemoconcentration during ECMO.