Risk factors for hemolysis with centrifugal pumps in pediatric extracorporeal membrane oxygenation: Is pump replacement an answer?

Abstract

Introduction Hemolysis during pediatric extracorporeal membrane oxygenation (ECMO) is associated with increased risk for renal failure and mortality. Objectives We aim to describe risk factors for hemolysis in pediatric ECMO supported by centrifugal pumps. Methods We conducted an analysis of retrospective data collected at an academic children’s hospital from January 2017 to December 2019. Measurements and results Plasma-free hemoglobin (PFH) levels were measured daily, and hemolysis was defined as PFH>50 mg/dL. Of 46 ECMO runs over 528 ECMO days, hemolysis occurred in 23 (58%) patients over a total of 40 (8%) ECMO days. In multivariable logistic regression models, VA-ECMO (aOR=4.69, 95% CI: 1.01–21.83) and higher hemoglobin (aOR = 1.38, 95% CI: 1.06–1.81) were independently associated with hemolysis. There were also non-significant trends toward increased risk for hemolysis with higher rotational pump speed (aOR=2.39, 95% CI: 0.75–7.65), higher packed red blood cell transfusions (aOR=1.15, 95% CI: 0.99–1.34), and higher cryoprecipitate transfusions (aOR=2.01, 95% CI: 0.83–4.86). Isolated pump exchanges that were performed in 12 patients with hemolysis led to significant decreases in PFH levels within 24 h (89 vs 11 mg/dL, p<0.01). Conclusions Hemolysis is common in pediatric ECMO using centrifugal pumps. Avoidance of high pump speeds and conservative administration of blood products may help to mitigate the risk for hemolysis. Furthermore, pump exchange may be an effective first-line treatment for hemolysis.

Therapeutic plasma exchange for mechanical red cell hemolysis: A case series

“…Numerous studies show the association of elevated PFH with AKI, and other adverse outcomes in patients on ECMO. [1][2][3][4] In addition, Betrus et al showed enhanced hemolysis during combined ECMO and CRRT compared with ECMO alone. 11 In a retrospective analysis of patients requiring ECMO (n = 207, median age 0.13 years), those with severe hemolysis (defined as peak PFH > 100 mg/dL) had greater odds of mortality in the intensive care unit (adjusted odds ratio [aOR]: 5.93; 95% confidence interval [CI]: 1.64-21.43) and hospital (aOR 6.34; 95% CI: 1.71-23.54).…”

“…Heme pigments can cause direct tubular injury, tubular obstruction, and lead to AKI. Numerous studies show the association of elevated PFH with AKI, and other adverse outcomes in patients on ECMO 1‐4 . In addition, Betrus et al showed enhanced hemolysis during combined ECMO and CRRT compared with ECMO alone 11 .…”

“…Mechanical red cell hemolysis and elevated serum plasma free hemoglobin (PFH) levels may be seen in pediatric patients requiring mechanical circulatory support devices. [1][2][3] Heme pigments released from the degradation of hemoglobin in the kidneys cause acute kidney injury (AKI) via tubular obstruction and direct proximal tubule epithelial cell injury. [4][5][6] Therapeutic plasma exchange (TPE) has been utilized to reduce PFH to improve associated morbidity.…”

Intravascular Hemolysis and AKI in Children Undergoing Extracorporeal Membrane Oxygenation

“…A cutoff of 50 mg/dl for plasma-free hemoglobin was used because this is well established in the ECMO literature. 6,11,14,15 For LDH, 2500 units/L was chosen because there were no values ,600 units/L when LDH was measured, and 2500 units/L was the upper limit of the lowest tertile of results. Hemoglobin and platelet counts were treated as continuous variables.…”