Eva W. Cheung

Centrifugal pumps and hemolysis in pediatric extracorporeal membrane oxygenation (ECMO) patients: An analysis of Extracorporeal Life Support Organization (ELSO) registry data

PURPOSE It is currently unclear whether centrifugal pumps cause more hemolysis than roller pumps in extracorporeal membrane oxygenation (ECMO) circuits. The aim of this study was to help answer that question in pediatric patients. METHODS A limited deidentified data set was extracted from the international multicenter Extracorporeal Life Support Organization (ELSO) registry comprising all reported ECMO runs for patients 18years or younger between 2010 and 2015. Logistic regression was used to evaluate a possible association between hemolysis and pump type, controlling for patient demographics, circuit factors, and complications. RESULTS 14,776 ECMO runs for 14,026 patients had pump type recorded. Centrifugal pumps were employed in 60.4% of ECMO circuits. Hemolysis was a reported complication for 1272 (14%) centrifugal pump runs and for 291 (5%) roller pump runs. 1755 (20%) centrifugal pump runs reported kidney injury as compared to 797 (14%) roller pump runs. In the full logistic regression, the odds of hemolysis were significantly greater for runs using centrifugal pumps (OR 3.3, 95% CI 2.9-3.8, p<0.001). CONCLUSIONS In this retrospective analysis of a large international data set, the use of centrifugal pumps was associated with increased rates of hemolysis, hyperbilirubinemia, and kidney injury. TYPE OF STUDY Retrospective cohort study. LEVEL OF EVIDENCE Level III.

Routine Use of Distal Arterial Perfusion in Pediatric Femoral Venoarterial Extracorporeal Membrane Oxygenation: ECMO FOR RESPIRATORY INDICATIONS AND CIRCULATORY SUPPORT

Lower-extremity ischemia is a significant complication in children on femoral venoarterial extracorporeal membrane oxygenation (VA ECMO). Our institution currently routinely uses distal perfusion catheters (DPCs) in all femoral arterial cannulations in attempts to reduce ischemia. We performed a single-center, retrospective review of pediatric patients supported with femoral VA ECMO from January 2005 to November 2015. The outcomes of patients with prophylactic DPC placement at cannulation (prophylactic DPC) were compared to a historical group with DPCs placed in response only to clinically evident ischemic changes (reactive DPC). Ischemic complication requiring invasive intervention (fasciotomy or amputation) was the primary outcome. Twenty-nine patients underwent a total of 31 femoral arterial cannulations, 17 with prophylactic DPC and 14 with reactive DPC. Ischemic complications requiring invasive intervention developed in 2 of 17 (12%) prophylactic DPC patients versus 4 of 14 (29%) reactive DPC. In the reactive DPC group, 7 of 14 (50%) had ischemic changes postcannulation, six underwent DPC placement, and three out of six of these patients still required invasive intervention. One of the seven patients had ischemic changes, did not undergo DPC, and required amputation. While a greater percentage of patients in the prophylactic group was cannulated during extracorporeal cardiopulmonary resuscitation (ECPR), statistical significance was not otherwise demonstrated. We demonstrate feasibility of superficial femoral artery (SFA) access in pediatric patients. We note fewer ischemic complications with prophylactic DPC placement, and observe that salvaging a limb with a reactive DPC was only successful 50% of the time. Although there was no statistical difference in the primary outcome between the two groups, limitations and confounding factors include small sample size and a greater percentage of patients in the prophylactic DPC group cannulated with ECPR in progress.

238: THE RELATIONSHIP OF PDA FLOW PATTERNS WITH CLINICAL PARAMETERS IN NEONATES ON VENOVENOUS ECMO

Critical Care Medicine • Volume 46 • Number 1 (Supplement) www.ccmjournal.org Learning Objectives: Extracorporeal membrane oxygenation (ECMO) has been used in over 27,000 neonates with respiratory failure. Of these, approximately 6,700 have been treated with venovenous (VV) ECMO. Currently, more of these patients are being supported with VV ECMO, as ligation of the carotid artery is spared and central nervous system complications are lessened. Increases in pulmonary vascular resistance (PVR) may lead to extra-pulmonary shunting of blood via right-to-left (R-L) flow through the patent ductus arteriosus (PDA) and patent foramen ovale. Previous studies have shown that R-L flow before ECMO initiation is associated with lower survival rates. We hypothesized that the direction of flow within and size of the PDA while on VV ECMO would be associated with the need for conversion to VA ECMO and to survival. Methods: A retrospective chart review of patients supported with VV ECMO for neonatal respiratory failure from January 2011 through September 2015 in 3 academic children’s hospitals. PDA size, direction of blood flow, and estimation of pulmonary artery pressure (or PVR if the PDA was non-restrictive) were recorded by echocardiography closest to 48 hours on ECMO. Chisquared and Fisher Exact test were used where appropriate. Univariate and multivariate regression was performed to compare variables associated with survival and conversion from VV to VA ECMO. Results: 41 patients were initially supported on VV ECMO. Of these, 8 (19%) were converted to VA ECMO, and 30 (73%) survived. The average hour on ECMO for the echocardiogram was 71 hours (range 20–167 hours). On univariate analysis lower weight, a higher vasoactive infusion score (VIS), and use of iNO, milrinone, sildenafil and iloprost were associated with conversion to VA ECMO. The absence of renal or neurologic diagnosis, lower VIS, and no need for iNO, milrinone and sildenafil were associated with increased survival to 24 hours after decannulation. PDA size and direction of blood flow were not associated with conversion to VA ECMO or survival. No variables remained significant on multivariate analysis. Conclusions: PDA size and flow pattern in patients already on VV ECMO were not associated with conversion to VA ECMO or survival to 24 hours after decannulation. On univariate analysis other factors were associated with these endpoints.