Building a Better Neonatal Extracorporeal Life Support Circuit: Comparison of Hemodynamic Performance and Gaseous Microemboli Handling in Different Pump and Oxygenator Technologies

Subdural extravasation of crystalloids and blood products through a scalp peripheral intravenous catheter into the subdural space of a neonate on veno-arterial extracorporeal membrane oxygenation

We describe a rare and devastating complication of a malpositioned scalp peripheral intravenous catheter (PIV) that resulted in subdural extravasation of infused fluids and midline shift in a critically ill neonate who required extracorporeal membrane oxygenation (ECMO). Recognition of increased intracranial pressure was hindered by the hemodynamic changes of being on ECMO and only identified by routine surveillance ultrasonography. Awareness of this complication may lead providers to seek alternate sites for vascular access in such patients, and encourage closer monitoring for this complication when an alternate site is unavailable.

Artificial Organs 2017: A Year in Review

In this Editor's Review, articles published in 2017 are organized by category and summarized. We provide a brief reflection of the research and progress in artificial organs intended to advance and better human life while providing insight for continued application of these technologies and methods. Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. Peer-reviewed Special Issues this year included contributions from the 12th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion edited by Dr. Akif Undar, Artificial Oxygen Carriers edited by Drs. Akira Kawaguchi and Jan Simoni, the 24th Congress of the International Society for Mechanical Circulatory Support edited by Dr. Toru Masuzawa, Challenges in the Field of Biomedical Devices: A Multidisciplinary Perspective edited by Dr. Vincenzo Piemonte and colleagues and Functional Electrical Stimulation edited by Dr. Winfried Mayr and colleagues. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years.

In Vitro Comparison of Two Neonatal ECMO Circuits Using a Roller or Centrifugal Pump With Three Different In-Line Hemoconcentrators for Maintaining Hemodynamic Energy Delivery to the Patient

The objective of this study was to compare three different hemoconcentrators (Hemocor HPH 400, Mini, and Junior) with two different neonatal ECMO circuits using a roller or a centrifugal pump at different pseudo-patient pressures and flow rates in terms of hemodynamic properties. This evidence-based research is necessary to optimize the ECMO circuitry for neonates. The circuits used a 300-mL soft-shell reservoir as a pseudo-patient approximating the blood volume of a 3 kg neonate, two blood pumps, and a Quadrox-iD Pediatric oxygenator with three different in-line hemoconcentrators (Hemocor HPH 400, Mini, and Junior). One circuit used a Maquet H20 roller pump and another circuit used a Maquet RotaFlow centrifugal pump. The circuit was primed with lactated Ringer's solution followed by heparinized packed red blood cells with a hematocrit of 40%. The pseudo-patient's pressure was manually maintained at 40, 60, or 80 mm Hg and the flow rate was maintained at 200, 400, or 600 mL/min with a circuit temperature of 36°C. Pressure and flow data was recorded using a custom-made data acquisition device. Mean pressures, diverted blood flow, pressure drops, and total hemodynamic energy (THE) were calculated for each experimental condition. The roller pump and centrifugal pump performed similarly for all hemodynamic properties with all experimental conditions. The Hemocor HPH Junior hemoconcentrator added the highest resistance to the circuit. The Hemocor HPH Junior provided the highest circuit pressures, lowest diverted blood flow, highest pressure drop across the circuit, and highest THE generated by the pump. The Hemocor HPH 400 added the least resistance to the circuit, providing the lowest circuit pressures, more diverted flow, lowest pressure drop, and the lowest THE generated by the pump. However, the THE delivered to the patient was the same for the three hemoconcentrators. While the three hemoconcentrators performed differently in terms of hemodynamic properties throughout the circuit, the THE transmitted to the patient was similar for all three hemoconcentrators due to the consistent pseudo-patient's pressure that was manually maintained for each trial. While the THE delivered to the patient indicates similar perfusion for these patients with any of the three hemoconcentrators, the differences in added resistance to the circuit may impact the decision of which hemoconcentrator is used. There was no clinically significant difference between the two circuits with the roller versus centrifugal pump in terms of hemodynamic properties in this study. Further in vivo research is warranted to confirm our findings.

Evaluation of Combined Extracorporeal Life Support and Continuous Renal Replacement Therapy on Hemodynamic Performance and Gaseous Microemboli Handling Ability in a Simulated Neonatal ECLS System

The objective of this study was to evaluate the hemodynamic performance and gaseous microemboli (GME) handling ability of a simulated neonatal extracorporeal life support (ECLS) circuit with an in-line continuous renal replacement therapy (CRRT) device. The circuit consisted of a Maquet RotaFlow centrifugal pump or HL20 roller pump, Quadrox-iD Pediatric diffusion membrane oxygenator, 8-Fr arterial cannula, 10-Fr venous cannula, and Better-Bladder (BB) with "Y" connector. A second Quadrox-I Adult oxygenator was added postarterial cannula for GME experiments. The circuit and pseudo-patient were primed with lactated Ringer's solution and packed human red blood cells (hematocrit 40%). All hemodynamic trials were conducted at ECLS flow rates ranging from 200 to 600 mL/min and CRRT flow rate of 75 mL/min at 36°C. Real-time pressure and flow data were recorded with a data acquisition system and GME were detected and characterized using the Emboli Detection and Classification Quantifier System. CRRT was added at distinct locations such that blood entered CRRT between the pump and oxygenator (A), recirculated through the pump (B), or bypassed the pump (C). With the centrifugal pump, all CRRT positions had similar flow rates, mean arterial pressure (MAP), and total hemodynamic energy (THE) loss. With the roller pump, C demonstrated increased flow rates (293.2-686.4 mL/min) and increased MAP (59.4-75.5 mm Hg) (P < 0.01); B had decreased flow rates (129.7-529.7 mL/min), and MAP (34.2-45.0 mm Hg) (P < 0.01); A maintained the same when compared to without CRRT. At 600 mL/min C lost more THE (81.4%) (P < 0.01) with a larger pressure drop across the oxygenator (95.6 mm Hg) (P < 0.01) than without CRRT (78.3%; 49.1 mm Hg) (P < 0.01). C also demonstrated a poorer GME handling ability using the roller pump, with 87.1% volume and 17.8% count reduction across the circuit, compared to A and B with 99.9% volume and 65.8-72.3% count reduction. These findings suggest that, in contrast to A and B, adding CRRT at position C is unsafe and not advised for clinical use.

In Vitro Evaluation of Pediatric Hollow-Fiber Membrane Oxygenators on Hemodynamic Performance and Gaseous Microemboli Handling: An International Multicenter/Multidisciplinary Approach

The objective of this study was to compare the hemodynamic performances and gaseous microemboli (GME) handling ability of two pediatric oxygenators in a simulated pediatric cardiopulmonary bypass (CPB) model and the importance of adding an arterial filter in the circuit. The circuit consisted of a Braile Infant oxygenator or a Maquet Quadrox-I Pediatric oxygenator without integrated arterial filter (parallel arrangement), 1/4 in. ID tubing A-V loop, and a 12-Fr arterial cannula, primed with lactated Ringer's solution and packed red blood cells. Trials were conducted at flow rates ranging from 500 to 2000 mL/min (500 mL/min increment) at 35°C and 28°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For GME testing, 5 cc of air was manually injected into the venous line. GME were recorded using the Emboli Detection and Classification Quantifier (EDAC) System. An additional experiment using a separate arterial filter was conducted. There was no difference in the mean circuit pressure, pressure drop, total hemodynamic energy level, and energy loss between the two oxygenators. The venous line pressures were higher in the Braile than in the Quadrox group during all trials (P <0.01). GME count and volume at pre-/post oxygenator and pre-cannula sites in the Quadrox were lower than the Braile group at high flow rates (P < 0.05). In the additional experiment, an arterial filter captured a significant number of microemboli at all flow rates. The Braile Infant oxygenator has a matched hemodynamic characteristic with the Quadrox-i Pediatric oxygenator. The Quadrox-i has a better GME handling ability compared with the Braile Infant oxygenator. Regardless of type of oxygenator an additional arterial filter decreases the number of GME.