Increased hemolysis from saline pre-washing RBCs or centrifugal pumps in neonatal ECMO

Abstract

Objectives: Hemolysis is a significant complication of extracorporeal membrane oxygenation (ECMO), with a reported incidence of 12.2%. The aims of this study were (1) to investigate hemolysis caused by saline-washed versus unwashed RBCs, (2) to determine in vitro the effects of saline washing on erythrocyte hemolytic markers and (3) to investigate hemolysis by centrifugal versus roller pumps.Study design: (1) To evaluate the effect of pre-transfusion saline-washing versus non-washing, the peak plasma-free hemoglobin (FHb) and total bilirubin in the first 3 days versus the next 4 days of ECMO were compared (2) Pre-and postsaline-washed RBCs were analyzed for K þ , hemoglobin, mean corpuscular volume, FHb and hemolysis at baseline and after 4 h of storage at 41C. (3) Over 10 000 neonatal ECMO cases were retrospectively reviewed to study the effect of pump type on hemolysis.Results: (1) The washed blood group had significantly more hemolysis within the first 3 days of ECMO. (2) Immediately after saline washing, the K þ and Hb concentrations were significantly decreased compared with unwashed blood, and these differences were maintained after 4 h. The osmotic fragility of washed RBCs after 4 h of storage at 41C was significantly higher than at baseline. (3) Hemolysis was reported more often in the centrifugal than in the roller pump group.Conclusions: (1) Using unwashed RBCs decreased hemolysis within the first 3 days of ECMO. (2) Saline washing, while decreasing the concentration of K þ in the plasma, significantly increases RBC membrane osmotic fragility. (3) Hemolysis is linked to the use of centrifugal pumps.

The Influence of Free Hemoglobin and Bilirubin on Heparin Monitoring by Activated Partial Thromboplastin Time and Anti-Xa Assay

“…We found aPTT is slightly shorter in the samples with elevated free Hb, in agreement with previous findings, [10][11][12] and aPTT values are further shortened by 5 to 20 seconds, depending on initial heparin and free Hb concentration in plasma samples. Although the exact mechanism of this finding is not known, direct activation of coagulation factors (V, VII, X) is suggested.…”

“…10 We found that hyperbilirubinemia and elevated level of free Hb in plasma samples provoked mild underestimation of heparin activity by anti-Xa assay. Colorimetric assays might be sensitive to high free Hb or high bilirubin in the specimen, and the anti-Xa assay Rotachrom is claimed to be insensitive to these substances unless bilirubin is higher than 6.6 mg/dL or Hb higher than 200 mg/dL.…”

Pathogenesis of non-antibody mediated transfusion-related acute lung injury from bench to bedside

“…Washing of stored RBCs may selectively eliminate these more fragile cells and thus prevent intravascular hemolysis [108]. On the other hand, washing may also damage cells increasing plasma free hemoglobin instead of preventing intravascular hemolysis [109]. Washing effects the plasma component by removal of mediators that accumulate during storage, for example potassium, cell-free hemoglobin, bio-active lipids and microparticles, and it eliminates residual antigens [108,110,111].…”

Hemolytic and thrombocytopathic characteristics of extracorporeal membrane oxygenation systems at simulated flow rate for neonates*

“…A 2004 Extracorporeal Life Support Organization registry analysis revealed that hemolysis occurred in 13.6% of all ECMO procedures with a higher incidence of dangerous hemolysis in centrifugal pumps (11). Prediction of severe hemorrhage during pediatric ECMO is challenging, because there is no currently acceptable specific clinical or laboratory marker (12, 13).…”