Neonatal Extracorporeal Life Support Research Articles

Use of point-of-care ultrasound (POCUS) to monitor neonatal and pediatric extracorporeal life support.

Extracorporeal membrane oxygenation (ECMO) is an invasive life support technique that requires a blood pump, an artificial membrane lung, and vascular cannulae to drain de-oxygenated blood, remove carbon dioxide, oxygenate, and return it to the patient. ECMO is generally used to provide advanced and prolonged cardiopulmonary support in patients with refractory acute cardiac and/or respiratory failure. After its first use in 1975 to manage a severe form of meconium aspiration syndrome with resultant pulmonary hypertension, the following years were dominated by the use of ECMO to manage neonatal respiratory failure and limited to a few centers across the world. In the 1990s, evidence for neonatal respiratory ECMO support increased; however, the number of cases began to decline with the use of newer pharmacologic therapies (e.g., inhaled nitric oxide, exogenous surfactant, and high-frequency oscillatory ventilation). On the contrary, pediatric ECMO sustained steady growth. Combined advances in ECMO technology and bedside medical management have improved general outcomes, although ECMO-related complications remain challenging. Point-of-care ultrasound (POCUS) is an essential tool to monitor all phases of neonatal and pediatric ECMO: evaluation of ECMO candidacy, ultrasound-guided ECMO cannulation, daily evaluation of heart and lung function and brain perfusion, detection and management of major complications, and weaning from ECMO support. Conclusion: Based on these considerations and on the lack of specific guidelines for the use of POCUS in the neonatal and pediatric ECMO setting, the aim of this paper is to provide a systematic overview for the application of POCUS during ECMO support in these populations. What is Known: • Extracorporeal membrane oxygenation (ECMO) provides advanced cardiopulmonary support for patients with refractory acute cardiac and/or respiratory failure and requires appropriate monitoring. • Point-of-care ultrasound (POCUS) is an accessible and adaptable tool to assess neonatal and pediatric cardiac and/or respiratory failure at bedside. What is New: • In this review, we discussed the use of POCUS to monitor and manage at bedside neonatal and pediatric patients supported with ECMO. • We explored the potential use of POCUS during all phases of ECMO support: pre-ECMO assessment, ECMO candidacy evaluation, daily evaluation of heart, lung and brain function, detection and troubleshooting of major complications, and weaning from ECMO support.

Response to Hemostatic Complications During Neonatal Extracorporeal Membrane Oxygenation: Roller Pump and Centrifugal Pump Driven Circuits.

To the Editor: Vermeer et al.1 recently published a case series and in vitro analysis of acute oxygenator failure manifested as a rise in preoxygenator pressure without evidence of gas transfer failure. As practitioners in the field who have fielded similar questions from colleagues describing similar issues, we applaud them for describing this problem that has been informally discussed in meetings and discussion boards for several years. The debate in neonatal extracorporeal life support (ECLS) between roller and centrifugal pumps has a long history.2 While the focus has primarily been on sources of increased hemolysis, the acute failure of the ECLS circuit by oxygenator clogging has received less attention. Vermeer et al.1 began using the RotaFlow in neonatal ECLS because of supply shortages and the availability and experience with adult ECLS. After a disturbing trend of complications, they embarked on a formal assessment of three systems (roller pump, RotaFlow, and PedIVAS) and associated failure rates in the neonatal population. The authors described anticoagulation, heat generation, and overall blood velocity as plausible mechanisms generating the cellular debris that led to the clogging phenomenon. In discussing the velocity, they came very close to what we would consider to be the fundamental problem inherent in the design of any centrifugal pump, which is their best efficiency point (BEP). The BEP is the point at which energy imparted to spinning the impeller generates the most forward bulk flow from the pump. The RotaFlow and PedivAS were designed to operate at 5 and 1.5 L/min, respectively. Schöps et al.3 used computational fluid dynamics to describe zones of recirculation, which do not contribute to the bulk flow of the blood, within adult devices operated at 1 L/min or less. Consequently, blood remains in the pump shear field for an extended time, significantly increasing the risk for hemolysis, which was demonstrated in vitro. Vermeer et al.1 have now provided in vivo evidence for the in silico and in vitro data provided by Schöps et al.3 However, we believe there is still more to the story. Several other factors are likely at play in neonatal ECLS, including cellular fragility4 and hemoglobin greater than 12–13 g/dl, which has been shown to be an independent factor leading to blood damage for neonatal ECLS regardless of pump type.5 A shrinking pool of devices and trained healthcare providers has led to the utilization of devices for the greatest number of patients (adults) in the most vulnerable population (neonates), and these are conditions for which these devices were never designed. Even the PediVAS, which is a pediatric device, is designed to operate at flow nearly three times that required for neonatal ECLS. We believe the study described by Vermeer et al.,1 Schöps et al.,3 Jenks et al.,5 and others in this space are important starting points for the ultimate discussion that a true neonatal ECLS centrifugal blood pump needs to be developed. We hope that such study continues and drives manufacturers to consider the needs of this population, ultimately allowing clinicians to more safely provide the life-saving support that this population needs.

Near-Infrared Spectroscopy as a Hemodynamic Monitoring Tool during Neonatal Extracorporeal Life Support: A Case Series

Near-infrared spectroscopy (NIRS) is a non-invasive clinical tool allowing for real-time, continuous measurement of regional tissue oxygenation (rSO2); though predominantly used for neuromonitoring, it also has the potential for early detection of hemodynamic compromise in the patients on extracorporeal life support (ECLS). The authors present two cases of neonates for whom continuous monitoring of multisite rSO2with NIRS provided the first indication of a significant compromise in hemodynamic status from catastrophic hemorrhagic complications while on ECLS ahead of conventional ECLS monitoring parameters. Routine NIRS monitoring of neonates on ECLS has utility for ongoing assessment of hemodynamic status and can be used for early detection of complications leading to impaired tissue perfusion.

Nutrition Considerations in Neonatal Extracorporeal Life Support.

Extracorporeal life support (ECLS) is a life-saving therapy, but neonates who require ECLS have unique nutritional needs and require aggressive, early nutritional support. These critically ill neonates are at increased risk for long-term feeding difficulties, malnutrition, and growth failure with associated increased morbidity and mortality. Unfortunately, few studies specific to this population exist. Clinical guidelines published by the American Society for Parenteral and Enteral Nutrition are specific to this population and available to aid clinicians in appropriate nutrition regimens, but studies to date suggest that nutrition provision varies greatly from center to center and often is inadequate. Though enteral feedings are becoming more common, aggressive parenteral nutrition is still needed to ensure nutrition goals are met, including the goal of increased protein provision. Long-term complications, including the need for tube feedings and growth failure, are common in neonatal ECLS survivors, particularly those with congenital diaphragmatic hernia. Oral aversion with poor feeding and growth failure must be anticipated and recognized early if present. The nutritional implications associated with the development of acute kidney injury, fluid overload, or the use of continuous renal replacement therapy must be recognized. In this state-of-the-art review, we examine aspects of nutrition for neonates receiving ECLS including nutritional requirements, nutrition provision, current practices, long-term outcomes, and special population considerations.

Pediatric and neonatal extracorporeal life support: current state and continuing evolution.

The use of extracorporeal life support (ECLS) for the pediatric and neonatal population continues to grow. At the same time, there have been dramatic improvements in the technology and safety of ECLS that have broadened the scope of its application. This article will review the evolving landscape of ECLS, including its expanding indications and shrinking contraindications. It will also describe traditional and hybrid cannulation strategies as well as changes in circuit components such as servo regulation, non-thrombogenic surfaces, and paracorporeal lung-assist devices. Finally, it will outline the modern approach to managing a patient on ECLS, including anticoagulation, sedation, rehabilitation, nutrition, and staffing.

627: Antithrombin Alters Time to Anticoagulation in Neonatal and Pediatric Extracorporeal Life Support

627: Antithrombin Alters Time to Anticoagulation in Neonatal and Pediatric Extracorporeal Life Support

Clinical outcomes of neonatal and pediatric extracorporeal life support: A seventeen-year, single institution experience.

The objective of this study was to describe a single-center experience with neonatal and pediatric extracorporeal life support (ECLS) and compare patient-related outcomes with those of the Extracorporeal Life Support Organization (ELSO) Registry. A retrospective review of subject characteristics, outcomes, and complications of patients who received the ECLS at Penn State Health Children's Hospital (PSHCH) from 2000 to 2016 was performed. Fisher's exact test was used to compare the PSHCH outcomes and complications to the ELSO Registry report. Data from 118 patients were included. Survival to discontinuation of the ECLS was 70.3% and 65.2% to discharge/transfer. Following circuitry equipment changes, the survival to discharge/transfer improved for both neonatal (<29 days) and pediatric (29 days to <18 years) patients. The most common complications associated with ECLS were clinical seizures, intracranial hemorrhage, and culture-proven infection. ECLS for pulmonary support appeared to be associated with a higher risk of circuit thrombus and cannula problems. When compared to the ELSO Registry, low volume ECLS centers, like our institution, can have outcomes that are no different or statistically better as noted with neonatal and pediatric cardiac patients. Pediatric patients requiring pulmonary support appeared to experience more mechanical complications during ECLS suggesting the need for ongoing technological improvement.

Left ventricular cardiac output is a reliable predictor of extracorporeal life support in neonates with congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is a treatable condition but despite optimal management, some patients require extracorporeal life support (ECLS). This study evaluates the association of left ventricular (LV) cardiac output and the need for ECLS. Single center, retrospective chart review from 1/1/2012 through 7/1/2018. Twenty-seven patients met criteria for evaluation with six patients (22%) requiring ECLS. Echocardiography was used to assess ventricular function. There was a statistically significant decrease in LV cardiac index of 1.33 L /min/m2 vs 1.80 L /min/m2 (p = 0.04) for patients requiring ECLS and non-ECLS, respectively. There was no difference between the 2 groups with regards to vasoactive medication use, surfactant use, iNO use, severity of pulmonary hypertension, or right ventricular (RV) function. In newborns with CDH, decreased LV cardiac output is more strongly associated with need for ECLS than severity of pulmonary hypertension or RV dysfunction.

Neonatal Extracorporeal Life Support: A Review of Nutrition Considerations.

Critically ill neonates who require extracorporeal life support have particular nutrition needs. These infants require prescription of aggressive, early nutrition support by knowledge providers. Understanding the unique metabolic demands and nutrition requirements of these fragile patients is paramount, particularly if additional therapies such as aggressive diuretic regimens or continuous renal replacement therapy are used concurrently. Although the American Society for Parenteral and Enteral Nutrition has published guidelines for this population, a review of each nutrition component is warranted because few studies exist specific to this population. Long-term complications in survivors of neonatal extracorporeal life support, particularly in patients with select diagnoses such as congenital diaphragmatic hernia, can be significant and must be recognized and anticipated. This review focuses on recognizing the nutrition needs of neonatal patients requiring extracorporeal life support, appraising the available data to guide selection of an appropriate mode of nutrition delivery, and describing the anticipated long-term nutrition implications of extracorporeal life support provision during the neonatal period.

Implementing a practice change: early initiation of continuous renal replacement therapy during neonatal extracorporeal life support standardizes care and improves short-term outcomes.

We hypothesized that a standardized approach to early continuous renal replacement therapy (CRRT) during neonatal extracorporeal life support (ECLS) results in greater homogeneity of CRRT initiation times with improvements in fluid balance and outcomes. Retrospective analysis of data (2007-2015) obtained from neonates treated prior to (E1; n = 32) and after (E2; n = 31) a 2011 practice change: CRRT initiation within 48h of ECLS. Birthweight, gestational age, ECLS mode, and age at ECLS initiation were similar to each epoch. Survival [E1: median 75%, E2: 71%] and length of ECLS [E1: median 221h, E2: 180 h] were comparable. During E2, 100% of infants received CRRT (vs. E1: 37%; p < 0.001) and 97% of infants initiated CRRT within 48h of ECLS (vs. E1: 13%; p < 0.001). Control charts demonstrate reduced practice variation. Elapsed time from ECLS to CRRT differed between Epochs [E1: median 105h, E2: 9h; p < 0.001] as did weight at CRRT initiation [E1: 4.13kg (29% above baseline), E2: 3.19kg (0%); p < 0.001]. Significant differences in weight change were noted on days 6 and 7 (E1: 14%, E2: 2%; raw data comparison yielded p < 0.05) and curves were different (p < 0.05). We successfully implemented a practice change, initiating CRRT within 48h of ECLS cannulation, leading to decreased practice variation and improved short-term outcomes including decreased weight gain at CRRT initiation and faster return to baseline weight during the first 7 days of ECLS. We did not demonstrate changes in duration of ECLS, invasive ventilation, or survival.

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 mmHg) (P < 0.01); B had decreased flow rates (129.7-529.7 mL/min), and MAP (34.2-45.0 mmHg) (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 mmHg) (P < 0.01) than without CRRT (78.3%; 49.1 mmHg) (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.

Hollow Fiber Oxygenator Composition Has a Significant Impact on Failure Rates in Neonates on Extracorporeal Membrane Oxygenation: A Retrospective Analysis.

In extracorporeal life support (ECLS), there are two main types of oxygenators in clinical use for neonates: polymethylpentene (PMP) hollow fiber and polypropylene (PP) hollow fiber. A retrospective study was performed on neonates ( n = 44) who had undergone ECLS for noncardiac indications from 2009 to 2015. Between the two groups (PMP n = 21, PP n = 23), the PP oxygenators failed 91% of the time, whereas the PMP oxygenators failed 43% of the time ( p < 0.05). Analysis suggests PMP oxygenators are less prone to failure than PP oxygenators, and they require fewer number of oxygenator changes during a neonatal ECLS.

Does an Open Recirculation Line Affect the Flow Rate and Pressure in a Neonatal Extracorporeal Life Support Circuit With a Centrifugal or Roller Pump?

The objective of this study is to evaluate the impact of an open or closed recirculation line on flow rate, circuit pressure, and hemodynamic energy transmission in simulated neonatal extracorporeal life support (ECLS) systems. The two neonatal ECLS circuits consisted of a Maquet HL20 roller pump (RP group) or a RotaFlow centrifugal pump (CP group), Quadrox-iD Pediatric oxygenator, and Biomedicus arterial and venous cannulae (8 Fr and 10 Fr) primed with lactated Ringer's solution and packed red blood cells (hematocrit 35%). Trials were conducted at flow rates ranging from 200 to 600 mL/min (200 mL/min increments) with a closed or open recirculation line at 36°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. In the RP group, the preoxygenator flow did not change when the recirculation line was open while the prearterial cannula flow decreased by 15.7-20.0% (P < 0.01). Circuit pressure, total circuit pressure drop, and hemodynamic energy delivered to patients also decreased (P < 0.01). In the CP group, the prearterial cannula flow did not change while preoxygenator flow increased by 13.6-18.8% (P < 0.01). Circuit pressure drop and hemodynamic energy transmission remained the same. The results showed that the shunt of an open recirculation line could decrease perfusion flow in patients in the ECLS circuit using a roller pump, but did not change perfusion flow in the circuit using a centrifugal pump. An additional flow sensor is needed to monitor perfusion flow in patients if any shunts exist in the ECLS circuit.

The use of neonatal extracorporeal life support in pediatric cardiac intensive care unit

Aim: The aim of the study is to evaluate extracorporeal life support system (ECLS) employed in neonates in pediatric cardiac intensive care unit.Material and methods: Twenty-five neonates that required ECLS in between November 2010 and November 2015 were evaluated.Results: The median age was 12 days (range 3–28 days) and the median body weight was 3 kg (range 2.5–5 kg). Venoarterial ECLS was performed in all of the cases. Ascendan aorta-right atrial cannulation in 22 patients and neck cannulation in three patients were performed. The reason for ECLS was E-CPR in two patients, inability to wean from cardiopulmonary bypass (CPB) in seven patients, respiratory insufficiency and hypoxia in nine patients, low cardiac output (LCOS) in seven patients. Median duration of ECLS was four days (range 1–15). Hemorrhagic complications developed in 15, renal complications in 13, pulmonary complications in 12, infectious complications in 11, neurologic complications in three and mechanical complications in two of the patients. Weaning was successful in 15 of the patients. Eleven patients were successfully discharged.Conclusion: ECLS is an important treatment option that is performed successfully in many centers around the world to maintain life support in patients unresponsive to medical treatment. The utilization of this modality especially in newborns with congenital heart disease should be taken into consideration.

Impact of Kidney Disease on Survival in Neonatal Extracorporeal Life Support.

To investigate the prevalence and survival to discharge of neonates with kidney disease who received extracorporeal life support. We analyzed the Extracorporeal Life Support Organization international registry of neonates (< 30 d old) who received extracorporeal life support from 1989 to 2012. We used International Classification of Diseases and Related Health Problems, 9th Revision, Clinical Modification, codes to identify neonates with kidney disease at time of cannulation for extracorporeal life support. Participating Extracorporeal Life Support Organization centers. All neonates who received extracorporeal life support at an Extracorporeal Life Support Organization center from 1989 to 2012. We performed bivariate logistic regression to estimate associations between survival and covariates. We used unadjusted and adjusted logistic regression to compare survival to discharge between neonates with and without kidney disease. Odds ratios were estimated separately for three groups based on extracorporeal life support indication: pulmonary indication without congenital diaphragmatic hernia, pulmonary indication with congenital diaphragmatic hernia, and cardiac indication. Adjusted models included covariates identified as significant in bivariate models for each group. The primary outcome measure was survival to discharge from hospitalization. Of the 28,755 neonates who received extracorporeal life support, 405 had kidney disease (extracorporeal life support indication: 210 pulmonary indication without congenital diaphragmatic hernia, 65 pulmonary indication with congenital diaphragmatic hernia, and 130 cardiac indication). Survival was lower in neonates with kidney disease than those without (49% vs 82% pulmonary indication without congenital diaphragmatic hernia, 25% vs 51% pulmonary indication with congenital diaphragmatic hernia, 21% vs 41% cardiac indication). Kidney disease was associated with reduced survival in adjusted models (95% CI for odds ratio 0.31-0.59 pulmonary indication without congenital diaphragmatic hernia, 0.27-0.89 pulmonary indication with congenital diaphragmatic hernia, 0.31-0.77 cardiac indication). Neonates with kidney disease who receive extracorporeal life support have poorer survival to discharge compared with other neonates who receive extracorporeal life support, suggesting that kidney disease should be considered when making extracorporeal life support initiation decisions.

Enteral nutrition in neonatal and pediatric extracorporeal life support: A survey of current practice

PurposeThe purpose of this study was to characterize enteral (EN) nutrition practices in neonatal and pediatric patients receiving extracorporeal life support (ECLS). MethodsA Web-based survey was administered to program directors and coordinators of Extracorporeal Life Support Organization centers providing neonatal and pediatric ECLS. The survey assessed patient and clinical factors relating to the administration of EN. ResultsA total of 122 responses (122/521, 23.4%) from 96 institutions (96/187; 51.3%) were received. One hundred fifteen provided neonatal or pediatric ECLS, and 84.2% reported utilizing EN during ECLS. 55% and 71% of respondents provide EN ‘often’ or ‘always’ for venoarterial and venovenous ECLS, respectively. EN was reported as given ‘often’ or ‘always’ by 24% with increased vasopressor support, 53% with “stable” vasopressor support, and 60% with weaning of vasopressor support. Favorable diagnosis for providing EN includes respiratory distress syndrome, pneumonia, asthma, trauma/post-operative, pulmonary hemorrhage, and infectious cardiomyopathy. Vasopressor requirement and underlying diagnosis were the primary or secondary determinant of whether to provide EN 81% and 72% of the time. 38% reported an established protocol for providing EN. ConclusionEN support is common but not uniform among neonatal and pediatric patients receiving ECLS. ECLS mode, vasopressor status, and underlying diagnosis play an important role in the decision to provide EN.

Pediatric and Neonatal Extracorporeal Life Support Technology Component Utilization: Are US Clinicians Implementing New Technology?

The objective of this investigation is to describe recent changes made in extracorporeal life support (ECLS) technology in the US Postal survey to directors and coordinators of all 125 US ECLS centers identified by Extracorporeal Life Support Organization as of November 2010, with follow-up of nonrespondents. Spearman coefficients were used to correlate the method of updating knowledge of ECLS technology with the likelihood of changing technology, and to correlate decision-making hierarchy with the likelihood of changing equipment. The response rate was 75% representing 34 states, and the majority of respondents were ECLS coordinators (56.6%). Respiratory diagnosis is the predominant indication for ECLS at any age. Over 40% of centers are using a hollow-fiber oxygenator for neonates and 80% of pediatric patients. Roller pumps are used in 70% of neonatal and pediatric ECLS. Forty-two percent of centers changed the oxygenator type within the past 3 years, while 30% changed both the oxygenator and pump. Less than 10% of centers reported problems with either oxygenator or pump in both neonates and pediatric ECLS. Forty-six percent of respondents that changed oxygenators cited that the primary reason for changing was "clinical preference/experience," while the other half was split between "FDA approval" and "Research results." In 40% of centers, a multidisciplinary group made decisions on changing technology. This survey indicates that over one-half of ECLS centers implemented new technology within the past 3 years. Knowledge of ECLS technology and safe operation of ECLS circuit components is essential in preventing some of the mechanical complications.

Impact of Oxygenator Selection on Hemodynamic Energy Indicators Under Pulsatile and Nonpulsatile Flow in a Neonatal Extracorporeal Life Support Model

This study compared the quality of perfusion delivered by two oxygenators--the hollow-fiber membrane Capiox Baby RX05 and silicone membrane Medtronic 0800--using hemodynamic energy indicators. The oxygenators were tested across varying flow rates and perfusion modes in a neonatal extracorporeal life support (ECLS) model. The experimental ECLS circuit included a Jostra HL-20 heart/lung machine with Jostra Roller pump, oxygenators with associated tubing and components, and a neonatal pseudo-patient. We used a 40/60 glycerin/water solution in the circuit as a blood analog. Testing occurred at flow rates of 250, 500, and 750 mL/min at 37°C under both pulsatile and nonpulsatile flow conditions. Hemodynamic data points consisted of recording 20-s intervals of data, and a total of 96 experimental repetitions were conducted. The pressure drop across the Capiox Baby RX05 oxygenator was significantly lower than the pressure drop across the Medtronic 0800 at all flow rates and perfusion modes. Furthermore, the Medtronic 0800 oxygenator showed significantly lower post-oxygenator energy equivalent pressures, total hemodynamic energy values, and surplus hemodynamic energy retention values compared to those of the Capiox Baby RX05. These results indicate the Medtronic 0800 oxygenator significantly dampens the hemodynamic energy compared to the Capiox Baby RX05. Consequently, clinical use of the Medtronic 0800 in a pulsatile ECLS setting is likely to mitigate the benefits provided by pulsatile flow. In contrast, the Capiox Baby RX05 better transmits hemodynamic energy to the patient with much lower pressure drop.

Hemodynamic evaluation of arterial and venous cannulae performance in a simulated neonatal extracorporeal life support circuit

To construct an ideal extracorporeal life support (ECLS) circuit in terms of hemodynamic performance, each component of the circuit should be evaluated. Most cannulae manufacturers evaluate their products using water as the priming solution. We conducted this study to evaluate the different sizes of arterial and venous cannulae in a simulated neonatal ECLS circuit primed with human blood. The simulated neonatal ECLS circuit was composed of a Capiox Baby RX05 oxygenator, a Rotaflow centrifugal pump and a heater & cooler unit. Three Medtronic Bio-Medicus arterial cannulae (8Fr, 10Fr, 12Fr) and three venous cannulae (10Fr, 12Fr, 14Fr) were tested in seven combinations (8A-10V, 8A-12V, 10A-10V, 10A-12V, 10A-14V, 12A-12V, 12A-14V). All the experiments were conducted using human blood at a hematocrit of 40% and at a constant temperature of 37°C. The "tip to tip" priming volume of the entire circuit was 135ml. The blood volume of the pseudo patient was 500ml. Flow rates increased linearly with increasing size in both venous and arterial cannulae at the same pump speeds. The increase in flow rate was greater when changing the arterial cannulae (next size larger) compared to changing the venous cannulae (next size larger). The pressure drops of the arterial cannula were correlated with the flow rates, regardless of the pseudo patient pressure and the venous cannula used simultaneously. The results show the difference in flow ranges and pressure drops of seven combinations of arterial and venous cannulae. It also suggests that the arterial cannula, not the venous cannula, has greater impact on the flow rate when a centrifugal pump is used in a neonatal ECLS circuit. The results of this study have been translated to further advancing the clinical practice in our institution.

Extracorporeal life support systems: alternative vs. conventional circuits

Emerging technologies and practices for pediatric and neonatal extracorporeal life support (ECLS) are promising. This experiment sought to compare the Medtronic 0800 silicon rubber membrane oxygenator to the Quadrox-iD Pediatric oxygenator in the conventional roller pump circuit, as well as comparing the conventional circuit to an alternative circuit. Three circuits were set up in the experiment. Two conventional roller pump circuits were used to compare the two oxygenators and an alternative circuit consisting of the Quadrox-iD Pediatric oxygenator and Maquet Rotaflow centrifugal pump system was used to identify differences between circuits. All three circuits were primed with Lactated Ringers' solution and human blood, with an hematocrit of 40%. Testing occurred at flow rates of 250, 500, and 750 ml/ min at 37°C for mean arterial line pressures of 60, 80, and 100 mmHg. The results of the experiment showed lower pressure drops and greater retention of total hemodynamic energy (THE) across the Quadrox-iD Pediatric oxygenator compared to the Medtronic 0800 oxygenator. Furthermore, the centrifugal pump used in the alternative circuit showed no back flow at flow rates as low as 250 ml/min while, on the other hand, rpm levels were kept below 2200 for flow rates as high as 750 ml/min. Findings support the usage of the Quadrox-iD Pediatric oxygenator in a circuit utilizing the Maquet Rotaflow centrifugal pump system due to lower pressure drops and greater percentage of THE retained across the circuit. Additional advantages of the alternative circuit include rapid set-up time, easy transport, lower priming volumes, and no gravity-dependent venous drainage system so that it can be situated in close proximity to and at the level of the patient.