First In Vivo Results of a Novel Pediatric Oxygenator with an Integrated Pulsatile Pump

Extracorporeal membrane oxygenation (ECMO) is a pivotal bridge to recovery for cardiopulmonary failure in children. Besides its life-saving quality, it is often associated with severe system-related complications, such as hemolysis, inflammation, and thromboembolism. Novel oxygenator and pump systems may reduce such ECMO-related complications. The ExMeTrA oxygenator is a newly designed pediatric oxygenator with an integrated pulsatile pump minimizing the priming volume and reducing the surface area of blood contact. The aim of our study was to investigate the feasibility and safety of this new ExMeTrA (expansion mediated transport and accumulation) oxygenator in an animal model. During 6 h of extracorporeal circulation (ECC) in pigs, parameters of the hemostatic system including coagulation, platelets and complement activation, and flow rates were investigated. A nonsignificant trend in C3 consumption, thrombin-antithrombin-III (TAT) complex formation and a slight trend in hemolysis were detected. During the ECC, the blood flow was constantly at 500 ml/min using only flexible silicone tubes inside the oxygenator as pulsatile pump. Our data clearly indicate that the hemostatic markers were only slightly influenced by the ExMeTrA oxygenator. Additionally, the oxygenator showed a constant quality of blood flow. Therefore, this novel pediatric oxygenator shows the potential to be used in pediatric and neonatal support with ECMO.

Blood Component Usage during Extracorporeal Membrane Oxygenation: Experience in 98 Patients at a Latin-American Tertiary Hospital

Background/Aims

Hemorrhagic complications during ECMO may affect a large proportion of the patients depending on the clinical setting. To guarantee optimal delivery of blood products to these patients, blood banks require updated information on the transfusion requirements. Few studies to date provide this information. This work assesses transfusion requirements in neonates and children during ECMO during the past 9 years.

Methods

We reviewed blood bank and hospital records of patients who underwent ECMO at our institution between May 2003 and May 2012. Data obtained included age, weight, diagnosis, type, length of ECMO, and daily transfusion requirements during ECMO. Descriptive and non-parametric inferential statistic analyses were performed. Our series included 98 patients.

Results

Mean time of patients on ECMO was 9.2 days, with the longest treatment spanning 22 days. Mean daily transfusion requirements were 39.5 ml/kg of RBC, 12.9 ml/kg of plasma, 34.3 ml/kg of platelets and 1.4 ml/kg of cryoprecipitate. Patients who underwent ECMO due to cardiac disease or congenital diaphragmatic hernia (CDH) required significantly higher transfusion volumes of plasma (p<0.05), platelets (p< 0.05) and cryoprecipitate (p<0.05) when compared to patients underwent ECMO due to respiratory disease. Concomitant with the aging of ECMO circuits, patients showed increased requirements of RBC, plasma, and CRYO around the seventh day of the ECMO run. This effect was not observed for platelets, which remained nearly consistent around 2.2 transfusions/day.

Conclusions

ECMO patients required significant transfusion support, which was particularly higher among patients who underwent ECMO due to cardiac disease or congenital diaphragmatic hernia.

Impact of pulsatile flow on hemodynamic energy in a Medos Deltastream DP3 pediatric extracorporeal life support system

The Medos Deltastream DP3 system is made up of a novel diagonal pump and hollow-membrane oxygenator that provides nonpulsatile and pulsatile flows for extracorporeal life support (ECLS). The objectives of this study are to (i) evaluate the efficacy of the hemodynamic energy provided by Medos Deltastream DP3 system in nonpulsatile and pulsatile mode and (ii) to evaluate the pulsatile mode under different frequencies. The experimental ECLS circuit was used in this study, primed with Ringer's lactate and packed red blood cells (hematocrit 35%). All trials were conducted at flow rates of 500, 1000, 1500, and 2000 mL/min with modified pulsatile frequencies of 60, 70, 80, and 90 bpm at 36°C. Simultaneous blood flow and pressures at the pre/postoxygenator and pre/postcannula sites were recorded for quantification of the pulsatile perfusion-generated energy-equivalent pressure (EEP), surplus hemodynamic energy (SHE), and total hemodynamic energy (THE). The experiments showed that under pulsatile flow conditions, at all flow rates and frequencies, (i) the EEP, SHE, and THE were significantly higher when compared with the nonpulsatile group and (ii) the pressure drop was minimal at lower flow rates and lower pulsatile frequencies but was significant when either the flow rate or the pulsatile frequency was increased. The Medos Deltastream DP3 System can provide nonpulsatile flow and physiologic quality pulsatile flow for pediatric ECLS. When the Medos DP3 pediatric ECLS system is used with pulsatile flow, there is more surplus hemodynamic energy and total hemodynamic energy than nonpulsatile flow.

Is hyperoxaemia helping or hurting patients during extracorporeal membrane oxygenation? Review of a complex problem

Extracorporeal membrane oxygenation (ECMO) facilitates organ support in patients with refractory cardiorespiratory failure whilst disease-modifying treatments can be administered. Improvements to the ECMO process have resulted in its increased utilisation. However, iatrogenic injuries remain, with bleeding and thrombosis the most significant concerns. Many factors contribute to the formation of thrombi, with the hyperoxaemia experienced during ECMO a potential contributor. Outside of ECMO, emerging evidence associates hyperoxaemia with increased mortality. Currently, no universal definition of hyperoxaemia exists, a gap in clinical standards that may impact patient outcomes. Hyperoxaemia has the potential to induce platelet activation, aggregation and, subsequently, thrombosis through markedly increasing the production of reactive oxygen species. There are minimal data in the current literature that explore the relationship between ECMO-induced hyperoxaemia and the production of reactive oxygen species – a putative link towards pathology. Furthermore, there is limited research directly linking hyperoxaemia and platelet activation. These are areas that warrant investigation as definitive data regarding the nascence of these pathological processes may delineate and define the relative risk of supranormal oxygen tension. These data could then assist in defining optimal oxygenation practice, reducing the risks associated with extracorporeal support.

The long duration of extracorporeal membrane oxygenation in a child with acute severe hypoxic respiratory failure treated in a resource-limited center

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has been indicated in patients with severe refractory respiratory failure from various causes for more than 30 years, even for the small infant.(1) Improved outcome from using ECMO for respiratory failure has been reported worldwide, ranging from 15% to over 50% in recent reviews.(1,2) The rationale of this therapy is to allow time for the lungs to heal, minimizing further lung injury from positive pressure ventilation.(3,4) We describe a case of severe acute respiratory distress syndrome (ARDS) with extensive barotrauma supported by VV-ECMO for 96 days in a resource-limited center. This is likely the longest ECMO support ever reported in a child.

Challenges at the Bedside With ECMO and VAD

Patients on circulatory support can be the source of multiple challenges including optimizing the circuit for specific congenital heart lesions, troubleshooting circuit failures, transporting patients on the circuit, anticoagulation and bleeding, transitioning to more mobile ventricular assist device, listing for thoracic organ transplantation, weaning from the circuit, and educating the patient and family about mechanical support. These challenges ideally require a specialized multidisciplinary team, which includes anesthesiologists, child life specialists, extracorporeal membrane oxygenation (ECMO) specialists, intensivists, nurses, nutritionists, perfusionists, pharmacists, respiratory therapists, social workers, and surgeons.