Extracorporeal Membrane Oxygenation Machine Research Articles

Non-pulsatile blood flow is associated with enhanced cerebrovascular carbon dioxide reactivity and an attenuated relationship between cerebral blood flow and regional brain oxygenation

BackgroundSystemic blood flow in patients on extracorporeal assist devices is frequently not or only minimally pulsatile. Loss of pulsatile brain perfusion, however, has been implicated in neurological complications. Furthermore, the adverse effects of absent pulsatility on the cerebral microcirculation are modulated similarly as CO2 vasoreactivity in resistance vessels. During support with an extracorporeal assist device swings in arterial carbon dioxide partial pressures (PaCO2) that determine cerebral oxygen delivery are not uncommon—especially when CO2 is eliminated by the respirator as well as via the gas exchanger of an extracorporeal membrane oxygenation machine. We, therefore, investigated whether non-pulsatile flow affects cerebrovascular CO2 reactivity (CVR) and regional brain oxygenation (rSO2).MethodsIn this prospective, single-centre case-control trial, we studied 32 patients undergoing elective cardiac surgery. Blood flow velocity in the middle cerebral artery (MCAv) as well as rSO2 was determined during step changes of PaCO2 between 30, 40, and 50 mmHg. Measurements were conducted on cardiopulmonary bypass during non-pulsatile and postoperatively under pulsatile blood flow at comparable test conditions. Corresponding changes of CVR and concomitant rSO2 alterations were determined for each flow mode. Each patient served as her own control.ResultsMCAv was generally lower during hypocapnia than during normocapnia and hypercapnia (p < 0.0001). However, the MCAv/PaCO2 slope during non-pulsatile flow was 14.4 cm/s/mmHg [CI 11.8–16.9] and 10.4 cm/s/mmHg [CI 7.9–13.0] after return of pulsatility (p = 0.03). During hypocapnia, non-pulsatile CVR (4.3 ± 1.7%/mmHg) was higher than pulsatile CVR (3.1 ± 1.3%/mmHg, p = 0.01). Independent of the flow mode, we observed a decline in rSO2 during hypocapnia and a corresponding rise during hypercapnia (p < 0.0001). However, the relationship between ΔrSO2 and ΔMCAv was less pronounced during non-pulsatile flow.ConclusionsNon-pulsatile perfusion is associated with enhanced cerebrovascular CVR resulting in greater relative decreases of cerebral blood flow during hypocapnia. Heterogenic microvascular perfusion may account for the attenuated ΔrSO2/ΔMCAv slope. Potential hazards related to this altered regulation of cerebral perfusion still need to be assessed.Trial registrationThe study was retrospectively registered on October 30, 2018, with Clinical Trial.gov (NCT03732651).

Towards next generation cannulation simulators

Background: Cannulation, in extracorporeal membrane oxygenation (ECMO), is the act of inserting a cannula through the body1. For femoral veins, femoral arteries, and the jugular vein, the cannula stops at the inferior vena cava (IVC) beside the hepatic vein and at the beginning of the distal aorta, and the superior vena cava at the right atrium, respectively. Cannulation is considered a critical operation and requires intensive training. Simulation-based training (SBT) is the gold standard, allowing for training in risk-free, versatile, and realistic environments2. A research collaboration was established between Hamad Medical Corporation and Qatar University College of Engineering to support the development of the ECMO training programme. Initially an ECMO machine simulator was developed with thermochromic ink to simulate blood and modules that simulate common emergencies practitioners may face during ECMO runs3. This cannulation simulator is now being designed to close the gap in the market in relation to cost and fidelity4,5. Methods: The cannulation simulator is composed of several modules. Firstly, a 3D-printed femoral pad mold was constructed to facilitate the production of cannulation pads (Figure 1(a), (c)). Secondly, cannulation pads were designed so they are anatomically correct and ultrasound compatible. For the arteries, the superficial artery was added at the access point to simulate possible incorrect routes for the cannula. Furthermore, the orientation of the veins and arteries were set to further resemble the human anatomy, where the arteries are situated above the veins (Figure 1(a), (b)). In addition to the implementation of a closed loop linking the jugular to the femoral, cannulation access points with a pump connected to a tank between them to regulate the flow. The blood flow in the arteries was enhanced with a pump to simulate a pulsatile flow while the flow in the veins is laminar as seen in the single loop implementation (Figure 1(h)). The connection of the pump to the embedded system is shown in Figure 1(g). The junctional point in the IVC was designed in the venous loop to allow for two cannulas to pass and an alternative path simulating the renal vein was added. A force sensing resistor (FSR) was connected to detect and measure incorrect entry of the guide-wire as this, in real-time scenarios, could cause internal bleeding to the patient (Figure 1(g)). Lastly, the Y-connector showing the renal vein entry is shown in Figure 1(d) and (e). Results: Tests were done on the system namely on the FSR to recalibrate it in the presence of liquid. Tests on the pulsatile flow were conducted to optimize for realism in terms of pressure. Since both jugular and femoral cannulation access points are included, the simulator can be used for training for all ECMO modes including veno-arterial and veno-venous. After testing, the main limitations of the current prototype include the flexibility of the tubes, limits on FSR measurements, and the rigidity of the available 3D printing material. Conclusion: After implementing the stated features, the anticipated outcome is a realistic and cost-efficient ECMO cannulation simulator.

Extracorporeal membrane oxygenation simulation-based training: methods, drawbacks and a novel solution.

Patients under the error-prone and complication-burdened extracorporeal membrane oxygenation (ECMO) are looked after by a highly trained, multidisciplinary team. Simulation-based training (SBT) affords ECMO centers the opportunity to equip practitioners with the technical dexterity required to manage emergencies. The aim of this article is to review ECMO SBT activities and technology followed by a novel solution to current challenges. The commonly-used simulation approach is easy-to-build as it requires a functioning ECMO machine and an altered circuit. Complications are simulated through manual circuit manipulations. However, scenario diversity is limited and often lacks physiological and/or mechanical authenticity. It is also expensive to continuously operate due to the consumption of highly specialized equipment. Commercial extensions can be added to enable remote control and to automate circuit manipulation, but do not improve on the realism or cost-effectiveness. To address those drawbacks, we are developing a standalone modular ECMO simulator that employs affordable technology for high-fidelity simulation.

Prototype of extracorporeal membrane oxygenation (ECMO) therapy simulator used in regional ECMO program.

Simulation is widely accepted as an important tool in training and educating healthcare providers. The first regional polish extracorporeal membrane oxygenation (ECMO) program called "ECMO for Greater Poland" was recently started. We present a prototype for ECMO prepared for high-fidelity medical simulation in extracorporeal life support. ECMO therapy is a complex, difficult and expensive therapy in patient care. We have constructed an advanced ECMO simulation prototype, which can be used as a training tool in scenarios that prepare for real-life experiences. The "ECMO for Greater Poland" program uses high-fidelity simulation as a superior tool to simulate several complex clinical scenarios, and consequently train healthcare providers in rare, complicated and expensive procedures. The training course is standardized and allows repeatable training, improvement of skills, and an objective verification of trained skills. The ECMO simulation prototype is designed to replicate the physiological circulatory system and simulate several scenarios (i.e., bleeding, low pressure, occlusion, reaction for proper and incorrect pharmacological treatment). The electronic core control unit (CCU) with silicone tubes, artificial vessels (modified polyethylene) and analog components can be connected to an ECMO machine to emulate the human body during an ECMO simulation. If necessary, damaged and used parts can easily be replaced. The total cost of the simulator is approximately 450 and 50 USD for disposable parts. This newly developed advanced ECMO simulation prototype was recently introduced into education and regularly training of healthcare providers of the "ECMO for Greater Poland" program. The simulation based training program is financially affordable and enables clinical teaching in a wider range of clinical scenarios. The ECMO simulation prototype consequently improves level of expertise of the healthcare providers and finally improves quality in patient care.

Addressing the challenges of ECMO simulation.

The patient's condition and high-risk nature of extracorporeal membrane oxygenation (ECMO) therapy force clinical services to ensure clinicians are properly trained and always ready to deal effectively with critical situations. Simulation-based education (SBE), from the simplest approaches to the most immersive modalities, helps promote optimum individual and team performance. The risks of SBE are negative learning, inauthenticity in learning and over-reliance on the participants' suspension of disbelief. This is especially relevant to ECMO SBE as circuit/patient interactions are difficult to fully simulate without confusing circuit alterations. Our efforts concentrate on making ECMO simulation easier and more realistic in order to reduce the current gap there is between SBE and real ECMO patient care. Issues to be overcome include controlling the circuit pressures, system failures, patient issues, blood colour and cost factors. Key to our developments are the hospital-university collaboration and research funding. A prototype ECMO simulator has been developed that allows for realistic ECMO SBE. The system emulates the ECMO machine interface with remotely controllable pressure parameters, haemorrhaging, line chattering, air bubble noise and simulated blood colour change. The prototype simulator allows the simulation of common ECMO emergencies through innovative solutions that enhance the fidelity of ECMO SBE and reduce the requirement for suspension of disbelief from participants. Future developments will encompass the patient cannulation aspect.

Anesthetic management of amniotic fluid embolism -- a multi-center, retrospective, cohort study

Introduction: Amniotic fluid embolism (AFE) is a rare and potentially lethal obstetric complication, commonly occurring during labor, delivery, or immediately postpartum. There is a paucity of data regarding incidence, risk factors, and clinical management. Our primary objective in this study was to evaluate clinical presentation of AFE and delineate anesthesia management of these cases.Methods: This 10 years retrospective multi-center cohort study was performed in five tertiary university-affiliated medical centers, between the years 2005 and 2015. All documented cases of AFE identified according to the ICD guidelines were reviewed manually to determine eligibility for AFE according to Clark’s criteria. All cases confirming Clark’s diagnosis were included in the cohort.Results: Throughout the study period, 20 cases of AFE were identified, with an incidence of 4.1 per 100,000 births. Average age at presentation was 35 ± 5 years. Seventy percent of cases presented during vaginal delivery, 20% occurred throughout a cesarean delivery, and 10% occurred during a dilation and evacuation procedure. The most common presenting symptom was sudden loss of consciousness in 12 parturients (66.7%), fetal bradycardia in 11 parturients (55%), and shortness of breath in 10 parturients (50%). Perimortem cesarean section was performed in 55% of cases, although only one case was performed in the delivery suite, while all others were performed in the operating room. Echocardiography was performed in 60% of the cases and all were pathological. Furthermore, 20% of cases were connected to an extracorporeal membrane oxygenation machine. There was a 15% mortality rate of 15%. A further 15% suffered major neurological disability, 25% suffered minor neurological morbidity, and 45% survived without severe complications.Conclusion: AFE is associated with significant maternal morbidity. This study highlights the importance of providing advanced training for the delivery suite staff for cases of maternal cardiovascular collapse secondary to AFE and increasing awareness for this rare and devastating obstetric condition.

Management strategies on venovenous extracorporeal membrane oxygenation

The use of venovenous extracorporeal membrane oxygenation (VV-ECMO) for severe acute respiratory failure (ARF) has considerably increased worldwide. Therefore, extracorporeal membrane oxygenation (ECMO) teams called for practical guidelines with clear objectives on how to manage ECMO on daily basis.1 All classical topics of intensive care management have been put in perspective with the use of ECMO, opening multiple areas of research. Good teamwork is the central pillar of any ECMO program. After starting an ECMO run, the medical team has to deal with a triangle including the patient, the ECMO machine, and their interaction. This unique interdependence makes the management challenging, as any change occurring on one side (patient or ECMO) will affect the other side. The priority is to diagnose and treat the cause of ARF. Bronchoscopy showed a reasonable safety for diagnostic yield and clearing airways. The optimization of the oxygen delivery is primordial within the acute period and is represented by matching the ECMO flow and the cardiac output, maintaining an adapted level of hemoglobin, and decreasing causes of high oxygen consumption.2 The management of volume status is essential for keeping a precise balance between the patient and the machine. Echocardiography is an essential tool that provides much information before cannulation on hemodynamic, access insufficiency once the patient is on ECMO, initial cannula positioning or readjustment, and finally tolerance to ECMO weaning before and after decannulation.3 Once ECMO provides adequate oxygenation delivery for the patient, the different parameters of mechanical ventilation have to be readjusted with an actual trend to decrease most of them: FiO2 (25%), inspiratory pressure (10 cm H2O), and respiratory rate (10 cycles/min) that results in ultra-protective lung ventilation with an expected tidal volume in a range of 1–3 ml/kg.4 More than knowing the “best” positive end expiratory pressure, a low driving pressure less than 1 cm H2O has to be targeted.5 This is to ensure that the lungs can rest and recover over time. The exact duration required to reach these settings to allow an improvement on oxygenation is unpredictable. The weaning process is challenging as the gas exchange function improvement and the lung compliance recovery are sometimes not concomitant. It requires daily monitoring to allow early extubation while on ECMO. The anticoagulation has to be balanced not only to avoid any clots in the circuit when just connected, but also to avoid any bleeding. Analgesia and sedation are important for the initial oxygen consumption after cannulation and have to be minimized from the second day to the third day. The goal is for the patient to receive sufficient oxygenation without pain. Depending on their tolerance, patients will sometimes be awake while on ECMO. Then, an active physiotherapy (PT) program including mobilization, sitting on the edge of the bed, standing up, and walking should follow the passive PT started from the first day on ECMO. Acute renal failure is common during ECMO and should be prevented and treated with renal replacement therapy. Many other points including nutritional support and nosocomial infection prevention are specifically integrated in the patient management. In summary, the management strategies on VV-ECMO are complex and require to master critical care and ECMO knowledge combined with a strong collaborative multidisciplinary environment. The goal is to wean patients from ECMO as soon as clinical parameters permit it while avoiding ECMO-related complications.

Monitoring and complications during neonatal/pediatric ECMO run

Extracorporeal membrane oxygenation (ECMO) is a commonly used form of mechanical circulatory support in children with congenital or acquired heart disease, and cardiac failure refractory to conventional medical treatments.1 The cardiac output is partially or completely provided by the ECMO machine. To assess how much support is needed at any given time, a constant balance of oxygen delivery and oxygen consumption is required. Permanent monitoring of flow, hemoglobin, arterial, and mixed venous saturations are key elements to provide the needed understanding and continuous guidance of body requirements, aiming at controlling and maintaining optimal management of the ECMO patient. Although ECMO is lifesaving in many circumstances, it bares challenges and certain risks of complications. Despite bioline-coated circuits, anticoagulation is required. Measurement of activated clotting time (ACT) and activated partial thromboplastin time (APTT) are both used to guide anticoagulation, but it is unclear which method is the best, and constant monitoring of the hemoglobin level allows the early detection of internal and external bleeding.2 For children, sedation and analgesia, most often in combination with paralysis, is unavoidable for a smooth ECMO run. On the other hand, with such treatment on board, it is almost impossible to assess the neurological status of the patient on ECMO. Different monitoring tools, such as cerebral near infrared spectroscopy (NIRS) and serial brain ultrasound studies, are used to estimate brain integrity and function, but further research is needed to show which methods are the most practical and useful to achieve a favorable outcome.3 Nutrition in critically ill children is known to be crucial but debated how to achieve as the gut perfusion can be impaired and therefore the risk of necrotizing enterocolitis (NEC) is increased. It is discussed if somatic perfusion by NIRS monitoring can help to avoid NEC.4 The kidney function is often impaired in these critically ill children and careful monitoring of kidney function and urine output leads the decision when to start which type of renal replacement therapy for renal clearance and/or fluid removal. Techniques available include peritoneal dialysis or continuous renal replacement therapy (CRRT) incorporated with the ECMO circuit. Medication dosing is under discussion in many centers as the circulatory volume is higher than normal. Adjustment of medication dosing could consequently be of great importance. Close monitoring of medications where toxic levels can be reached is crucial to avoid further damage to the patient's organ functions.

ECMO nurse specialist: Qatar experience

As part of the National Health Strategy in the State of Qatar to improve the healthcare sector, the Critical Care Service in Hamad General Hospital (HGH) sets up an extracorporeal membrane oxygenation (ECMO) service within the Medical Intensive Care Unit (MICU) to enhance the care provided to critically ill patients. The new service demands a new technology and specific staff training in order to maintain high standards and safe care. Therefore, our initial investment was in training the team following ELSO guidelines and the purchase of ECMO equipment, especially for the adult population in our case. In the State of Qatar, the first use of ECMO treatment as respiratory support was in May 2014. Our experience supports other research that this technique requires expert knowledge and skills to deliver best and safe practice.1 We believe that this can be developed through regular practice and interaction at the bedside with patients and the ECMO technical equipment. Moreover, planning a robust ECMO education programme for the team is central to improving the quality of care and safety that we provide to these vulnerable patients. As part of our preparation process, in November 2013, six ICU nurses attended the ECMO specialist training course in London (UK). Since then, continuing educational programme has been established to train all the whole MICU nursing team focused on ECMO patient care. Several in-house training workshops and external re-training programmes were provided to nurses to develop their theoretical knowledge and technical skills with other members of the clinical team. In addition, we have performed simulation training that focused on multidisciplinary team, emphasising that teamwork is important and necessary for the care of such patients. The ECMO specialised nurse who takes care of these patients is educated to provide specialised assessment, appropriate monitoring, and clinical reasoning interventions. In addition to manipulating the ECMO machine, understanding ventilation requirements and the patient's medical treatment is crucial to help the ECMO nurses detect the signs of deterioration early and intervene immediately. Therefore, naturally, the role of the ECMO nurse has expanded and tends to be developed with theoretical and technological developments.2 The primary roles being close monitoring of alterations in blood flow and observation and maintenance of the circuit, and also an ability to assess the risks and assist with patient care. We also compared the role of the ECMO specialist nurse versus the role of the perfusionist. We believe in the importance of both roles; however, we argue that when the ECMO nurse works alongside the ICU bedside nurse, the bedside care becomes more effective. Both nurses and perfusionists are able to understand the patient's overall condition and needs during the ECMO run, and have better interpretation regarding observed changes.3 The partnership promotes the continuity of patient care and allows better communication and support of the family as an aspect of care. This also increases the opportunity of bedside training and education and allows developing other nurses under supervision. Overall, with proper planning, education, and structuring of ECMO care, we were able to obtain outcomes that are similar to those reported internationally. We aim to further improve patient outcome, especially regarding post-ICU discharge as part of holistic nursing care.

ECLS: Past, present, and future

Extracorporeal life support (ECLS) is the prototype example of translational research. It began in laboratory studies to design, test, and characterize devices for prolonged extracorporeal circulation in the 1960s. The first clinical cases of ECLS for heart and lung failure were in the 1970s. These cases were met with skepticism, but the results in neonatal respiratory failure were encouraging. In the early 1980s, two centers conducted randomized trials in neonates, which demonstrated much higher survival with ECLS, and the term extracorporeal membrane oxygenation (ECMO) was coined. By 1986, there were 18 neonatal ECMO centers and data on 700 cases. These centers formed a consortium (The Extracorporeal Life Support Organization: ELSO) to maintain the registry, define guidelines and techniques, provide education, and hold an annual meeting. In the 1990s, these centers expanded indications to older children with lung and heart failure. ECMO management for post-operative cardiac failure became standard in major pediatric heart centers. A multi-center randomized trial in the UK demonstrated a major survival advantage to ECMO in neonates. A few centers continued to evaluate and improve ECMO and extracorporeal CO2 removal (ECCOR) in adults with 50–60% survival in uncontrolled case series. At the ELSO meeting in 1999, a group met to plan a randomized trial in adult respiratory failure (ARDS). That study was carried out in the UK from 2002 to 2006 (the CESAR trial) using the same study design as the neonatal trial. The results were similar to the neonatal trial but adult intensivists were still skeptical, arguing that the single ECMO center in Leicester was just better at respiratory care than the other non-ECMO centers. During all this time, we used modified pumps, oxygenators, and other equipment designed for cardiac surgery. A new medical profession of “ECMO specialist” developed to manage the ECMO system and patient. The number of specialists determined the number of ECMO cases that could be treated. Around 2008, a few companies made major improvements in these devices and manufactured specific ECMO machines. These machines were much safer, simpler, and reliable than the early ECMO equipment, and patients could be managed for weeks, primarily by the bedside ICU nurse with support from the specialist. This new equipment came along at the same time as the H1N1 flu pandemic of 2008–2009. ECMO was remarkably successful in saving the sickest patients, and adult intensivists scrambled to learn the technology. This was born out by two matched-pairs trials. ECMO for ARDS (acute respiratory disease syndrome) grew rapidly in adult intensive care units (ICU). The use of awake ambulatory ECMO as a bridge to lung transplantation has been expanded to all ECMO patients, in fact, to all ICU patients.1 Currently, ECMO is used for severe heart and lung failure in all ages. Research is focused on improving anticoagulation and devices, defining indications, and new applications like septic shock, ECPR for cardiac arrest, and EDCD to salvage organs for transplantation. Laboratory research has continued as clinical practice proceeded, and it currently includes an artificial placenta for very premature infants and four versions of implantable, wearable lungs for chronic support.2

12 ways to take a temperature

12 ways to take a temperature

Dying feet in ICU: why might extracorporeal membrane oxygenation machines cause necrotic feet?

Background Extracorporeal membrane oxygenation (ECMO) is used for severe lung and/or heart failure in intensive care units (ICU). The Prince Charles Hospital (TPCH) has one of the largest ECMO units in Australia. Its use rapidly increased during the H1N1 (“swine flu”) pandemic and an increase in pedal complications resulted. The relationship between ECMO and pedal complications has been described, particularly in children, though no strong data exists. This paper presents a case series of foot complications in patients having received ECMO treatment.

Eight-year follow-up after palliative embolization of a neonatal intracranial dural arteriovenous fistula with high-output heart failure: management strategies for symptomatic fistula growth and bilateral femoral occlusions in pediatric patients

The authors report the 8-year follow-up of a patient previously described in the literature who originally presented in high-output cardiac failure secondary to a complex neonatal intracranial dural arteriovenous fistula (DAVF). The earlier case report described palliative treatment with a combination of extracorporeal membrane oxygenation (ECMO) and endovascular embolization for life-threatening high-output cardiac failure secondary to a DAVF. Access was obtained using the ECMO cannula, and embolization was performed while the patient was connected to the ECMO machine. The patient made an excellent recovery following partial embolization of the fistula, but then presented again 7 years later with worsening headaches secondary to significant growth of the known residual portion of the fistula identified on CT angiography. The child also developed bilateral femoral artery (FA) occlusions secondary to multiple previous FA punctures. To achieve complete obliteration of the remaining fistula, the patient required a retroperitoneal approach to the iliac artery and percutaneous puncture of the internal jugular vein. Embolization was performed with a combination of platinum coils and ethylene vinyl alcohol copolymer liquid embolic agent. There were no complications, and the child remains neurologically normal, with no signs of permanent cardiovascular sequelae. In this case report, the authors discuss the long-term management of AVFs treated by endovascular strategies early in life. After neonatal access, sometimes the FAs occlude, requiring more invasive access strategies. The authors also discuss the follow-up method, intervals, and threshold for further treatment for these lesions, and present a review of the literature.

Use of Mechanical Circulatory Support in Pediatric Patients With Acute Cardiac Graft Rejection

Patients suffering from acute cardiac graft rejection can die because of hemodynamic collapse while being treated with vigorous immunosuppressive therapies. There is little pediatric data on the use of mechanical circulatory support (MCS) in patients with acute cardiac graft rejection accompanied by hemodynamic instability. This report reviews our experience using MCS in patients with severe acute allograft rejection and cardiogenic shock. Between July 1995 and December 2006, 7 of 117 heart transplant recipients (6%) had MCS placed in 8 cases of acute graft rejection with hemodynamic instability. Devices used were BioMedicus (five), Thoratec (two), and extracorporeal membrane oxygenation machine (one). Mean age was 12 +/- 6.6 years. Median duration of support was 7.5 days (range, 3-28 days). Medical therapy applied included pulse steroids (eight), antithymocyte globulin (five), intravenous immunoglobulins (five), and plasmapheresis (five). Eighty-eight percent (seven of eight cases) weaned from MCS. Five patients weaned to recovery and two were bridged to retransplant. Five of the seven patients weaned (71%) were discharged home, all with normal left ventricular function. Median follow-up was 3.0 years (4.5 months to 3.5 years). One-year survival is 50% and 3 year survival is 38%. Mechanical circulatory support can be applied in patients with acute cardiac graft rejection causing hemodynamic instability with acceptable weaning and discharge rates. Unfortunately, late survival for this cohort remains poor.

Continuous Hemofiltration dose Calculation in a Newborn Patient with Congenital Heart Disease and Preoperative Renal Failure

To report a case of a newborn patient with renal failure due to polycystic kidneys requiring renal replacement therapy, and total anomalous pulmonary venous return requiring major cardiosurgical intervention. Pediatric cardiosurgery operatory room and pediatric cardiologic intensive care. A 6-day-old newborn child weighing 3.1 kg. Renal function (creatinine value and urine output) was monitored during the course of the operation and intraoperative renal replacement therapy was not initiated. Serum creatinine concentration decreased from 4.4 to 3 mg/dL at cardiopulmonary bypass (CPB) start and to 1.5 at the end of surgery: the creatinine decrease was provided by the dilutional effect of CPB priming and the infusion of fresh blood from transfusions together with an adequate filtration rate (800 m/L in about 120 minutes). After the operation, extracorporeal membrane oxygenation (ECMO) for ventricular dysfunction and continuous hemofiltration for anuria refractory to medical therapy were prescribed. The hemofiltration machine was set in parallel with the ECMO machine at a blood flow rate of 60 ml/min and a predilution replacement solution infusion of 600 ml/h (4.5 ml/min of creatinine clearance once adjusted on extracorporeal circuits; 3000 mL/m2 hemofiltration): after a single hemofiltration session lasting 96 hours, serum creatinine reached optimal steady state levels around 0.5 mg/dL on postoperative day 2 and 3. Administration of intraoperative continuous hemofiltration is not mandatory in the case of a 3-kg newborn patient with established renal failure needing major cardiosurgery: hemodilution secondary to CPB, transfusion of hemoderivates, and optimal UF rate appear to be effective methods for achieving solute removal. If postoperative continuous hemofiltration is started, however, a "dialytic dose" of 4.5 ml/min allows an adequate creatinine clearance, quick achievement of a steady state of serum creatinine concentration and an eventual acceptable rate of inflammatory mediator removal.

Reflections and Visions: 50 Years of Presidential Addresses

Reflections and Visions: 50 Years of Presidential Addresses