2024 FSA Podium and Poster Abstracts
P084: PREDICTIVE VALUE FOR DEATH OF PLASMA FREE HEMOGLOBIN (PFH) IN ECMO FOR CARDIAC VS. PULMONARY PATIENTS
Wasiq Rashid, BS1; Joby Chandy, MD2; Maha Balouch, CCRP2; Peter Wu, MD2; Enrico Camporesi, MD2; John Hodgson, MD2; 1University of South Florida Morsani College of Medicine; 2TEAMHealth Anesthesia
Introduction: A significant complication of ECMO is its facilitation of hemolysis and subsequent complications. Plasma-free hemoglobin (PFH) is an indicator of hemolysis, and PFH levels >50 mg/dL within 24 hours of ECMO initiation are an independent mortality predictor among patients on ECMO1. In recent years, ECMO support has also expanded for the treatment of COVID-19 patients showing signs of critical illness, (ARDS and pulmonary emboli). We analyzed if higher PFH values in this group of pulmonary patients would also correlate with a higher mortality rate. We evaluated if this could also be true for COVID and other non-COVID pulmonary patients.
Methods: We conducted a retrospective study of 122 patients who received ECMO support at our tertiary institution between January 2020 and December 2021. Patients were sorted by COVID Pulmonary, non-COVID Pulmonary (usually awaiting lung transplant), or Cardiac (with acute heart failure); as well as Expired (died during ECMO, or <30 days after ECMO) or Survived (survived >30 days after ECMO). We collected relevant patient data, including PFH values for each day a patient was on ECMO support. We averaged and recorded PFH values during the last 3 days on ECMO. We also collected age, BMI, and duration of treatment for each patient. Each variable was analyzed with a two-tailed T-Test to compare differences between Expired vs. Survived patients, and separately to compare COVID Pulmonary vs. non-COVID Pulmonary vs. Cardiac patients. All Cardiac patients received veno-arterial (VA) ECMO, and most Pulmonary patients received veno-venous (VV) ECMO. P values < 0.05 indicate significance.
All patients studied are listed in Table 1.
Results: COVID-19 pulmonary patients were significantly younger than Cardiac patients, regardless of survival status. COVID-19 pulmonary patients who expired were significantly older than those who survived. Additionally, COVID Pulmonary patients received ECMO support for significantly longer periods than non-COVID Pulmonary or Cardiac patients. COVID pulmonary patients who expired had significantly higher PFH values over the last 3 days than those who survived. However, COVID patients had significantly lower PFH values than Cardiac patients, regardless of survival status. (Table 2: see arrows).
Discussion: COVID Pulmonary patients survived on ECMO significantly longer than both groups, consistent with previous research2,3. Elderly COVID Pulmonary patients fared worse mortality outcomes than younger patients. Additionally, sustained spikes in PFH over the last 3 days may predict mortality among COVID-19 pulmonary patients receiving ECMO support. VA ECMO (Cardiac) is more prone to earlier hemolysis, as indicated by significantly higher PFH values in Cardiac patients. This trend is also supported by previous research4. However, it must be noted that several technical cannulation differences, as well as the frequent use of an Impella pump (to unload the left ventricle) in many cardiac patients, may introduce additional stresses on the blood and increase PFH values.
References
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2. SAIO J. 2022;68(4):478-485. doi: 10.1097/MAT.0000000000001632. PMID: 35349522.
3. Cureus. 2022 Jul 31;14(7):e27522. doi: 10.7759/cureus.27522. PMID: 36060406; PMCID: PMC9427068.
4. PLoS One. 2020 Jan 27;15(1):e0227793. doi: 10.1371/journal.pone.0227793. PMID: 31986168; PMCID: PMC6984694.