Functional performance of different venous limb options in simulated neonatal/pediatric cardiopulmonary bypass circuits

Abstract Objective: Hemodilution is a concern in cardiopulmonary bypass (CPB). Using a smaller dual tubing rather than a single larger inner diameter (ID) tubing in the venous limb to decrease prime volume has been a standard practice. The purpose of this study is to evaluate these tubing options. Methods: Four different CPB circuits primed with blood (hematocrit 30%) were investigated. Two setups were used with two circuits for each one. In Setup I, a neonatal oxygenator was connected to dual 3/16" ID venous limbs (Circuit A) or to a single 1/4" ID venous limb (Circuit B); and in Setup II, a pediatric oxygenator was connected to dual 1/4" ID venous limbs (Circuit C) or a single 3/8" ID venous limb (Circuit D). Trials were conducted at arterial flow rates of 500 ml/min up to 1500 ml/min (Setup I) and up to 3000 ml/min (Setup II), at 36°C and 28°C. Results: Circuit B exhibited a higher venous flow rate than Circuit A, and Circuit D exhibited a higher venous flow rate than Circuit C, at both temperatures. Flow resistance was significantly higher in Circuits A and C than in Circuits B (P<0.001) and D (P<0.001), respectively. Conclusion: A single 1/4" venous limb is better than dual 3/16" venous limbs at all flow rates, up to 1500 ml/min. Moreover, a single 3/8" venous limb is better than dual 1/4" venous limbs, up to 3000 ml/min. Our findings strongly suggest a revision of perfusion practice to include single venous limb circuits for CPB.

Anticoagulation Therapy during Extracorporeal Membrane Oxygenator Support in Pediatric Patients / 전남의대학술지

Extracorporeal membrane oxygenation (ECMO) is a salvage therapy for critically ill patients. Although ECMO is becoming more common, hemorrhagic and thromboembolic complications remain the major causes of death in patients undergoing ECMO treatments. These complications commence upon blood contact with artificial surfaces of the circuit, blood pump, and oxygenator system. Therefore, anticoagulation therapy is required in most cases to prevent these problems. Anticoagulation is more complicated in pediatric patients than in adults, and the foreign surface of ECMO only increases the complexity of systemic anticoagulation. In this review, we discuss the pathophysiology of coagulation, anticoagulants, and monitoring tools in pediatric patients receiving ECMO.

Anticoagulation Therapy during Extracorporeal Membrane Oxygenator Support in Pediatric Patients / 전남의대학술지

Extracorporeal membrane oxygenation (ECMO) is a salvage therapy for critically ill patients. Although ECMO is becoming more common, hemorrhagic and thromboembolic complications remain the major causes of death in patients undergoing ECMO treatments. These complications commence upon blood contact with artificial surfaces of the circuit, blood pump, and oxygenator system. Therefore, anticoagulation therapy is required in most cases to prevent these problems. Anticoagulation is more complicated in pediatric patients than in adults, and the foreign surface of ECMO only increases the complexity of systemic anticoagulation. In this review, we discuss the pathophysiology of coagulation, anticoagulants, and monitoring tools in pediatric patients receiving ECMO.

Experience with Mechanical Circulatory Support for Medically Intractable Low Cardiac Output in a Pediatric Intensive Care Unit

BACKGROUND AND OBJECTIVES: Mechanical circulatory support with extracorporeal membrane oxygenation (ECMO) and ventricular assist device has always been the optimal choice for treating the majority of medically intractable low cardiac output case. We retrospectively investigated our institution's outcomes and variables associated with a high risk of mortality. SUBJECTS AND METHODS: From 1999 to 2014, 86 patients who were of pediatric age or had grown-up congenital heart disease underwent mechanical circulatory support for medically intractable low cardiac output in our pediatric intensive care unit. Of these, 9 grown-up congenital heart disease patients were over 18 years of age, and the median age of the subject group was 5.82 years (range: 1 day to 41.6 years). A review of all demographic, clinical, and surgical data and survival analysis were performed. RESULTS: A total of 45 (52.3%) patients were successfully weaned from the mechanical assist device, and 25 (29.1%) survivors were able to be discharged. There was no significant difference in results between patients over 18 years and under 18 years of age. Risk factors for mortality were younger age (<30 days), functional single ventricle anatomy, support after cardiac operations, longer support duration, and deteriorated pre-ECMO status (severe metabolic acidosis and increased levels of lactate, creatinine, bilirubin, or liver enzyme). The survival rate has improved since 2010 (from 25% before 2010 to 35% after 2010), when we introduced an upgraded oxygenator, activated heart transplantation, and also began to apply ECMO before the end-stage of cardiac dysfunction, even though we could not reveal significant correlations between survival rate and changed strategies associated with ECMO. CONCLUSION: Mechanical circulatory support has played a critical role and has had a dramatic effect on survival in patients with medically intractable heart failure, particularly in recent years. Meticulous monitoring of acid-base status, laboratory findings, and early and liberal applications are recommended to improve outcomes without critical complication rates, particularly in neonates with single ventricle physiology.

Cardiopulmonary bypass: development of John Gibbon's heart-lung machine / Circulação extracorpórea: desenvolvimento da máquina de coração-pulmão de John Gibbon

Abstract Objective: To provide a brief review of the development of cardiopulmonary bypass. Methods: A review of the literature on the development of extracorporeal circulation techniques, their essential role in cardiovascular surgery, and the complications associated with their use, including hemolysis and inflammation. Results: The advancement of extracorporeal circulation techniques has played an essential role in minimizing the complications of cardiopulmonary bypass, which can range from various degrees of tissue injury to multiple organ dysfunction syndrome. Investigators have long researched the ways in which cardiopulmonary bypass may insult the human body. Potential solutions arose and laid the groundwork for development of safer postoperative care strategies. Conclusion: Steady progress has been made in cardiopulmonary bypass in the decades since it was first conceived of by Gibbon. Despite the constant evolution of cardiopulmonary bypass techniques and attempts to minimize their complications, it is still essential that clinicians respect the particularities of each patient's physiological function. .

Resumo Objetivo: Relatar de forma simples e resumida o desenvolvimento da circulação extracorpórea. Métodos: Realizada revisão de literatura sobre a evolução da circulação extracorpórea, seu papel fundamental para cirurgia cardiovascular e as complicações que podem surgir após o seu uso, dentre elas, a hemólise e a inflamação. Resultados: O processo de desenvolvimento da circulação extracorpórea foi fundamental, diminuindo as complicações desencadeadas por ela, que acabam por repercutir no paciente, variando de lesões de graus variados até falência de múltiplos órgãos. Os pesquisadores estudaram quais as agressões que a circulação extracorpórea poderia suscitar no organismo humano. Possíveis soluções surgiram e, consequentemente, meios mais adequados para uma condução mais segura do pós-operatório foram propostas. Conclusão: A circulação extracorpórea progrediu a passos firmes e seguros ao longo destas últimas décadas desde a sua concepção por Gibbon. Apesar da sua evolução e das condutas realizadas na tentativa de amenizar as complicações, o respeito aos detalhes das funções fisiológicas do paciente é fundamental. .

Recommendations for Establishing Cardiac Rehabilitation Programs; Facility, Equipment and Staff: The Korean Society of Cardiac Rehabilitation (KSCR) Position Statement

The Korean Society of Cardiac Rehabilitation (KSCR) have recommended standards for establishing cardiac rehabilitation programs in terms of facility, equipment and staff. This is the first time a statement concerning these types of standards has been issued in Korea, and presents the minimal requirements for establishing cardiac rehabilitation programs. Cardiac rehabilitation facilities should contain individual spaces for patient examination, exercise stress testing, monitoring exercise training, patient education, patient preparation, storing medical records, showers and lockers, toilets, and walking tracks. Essential equipment must include at least four sets of aerobic exercise equipment such as treadmills, bicycles, arm ergometers, step machines, and floor mats, and medical equipment such as exercise stress test for ECG with gas analysis, telemetry ECG monitoring systems, sphygmomanometers, stethoscopes, pulse oximeters, glucometers, portable oxygenators, and emergency carts with defibrillators. Hospital staff should include a medical director (a physician with a subspecialty in cardiac rehabilitation), exercise physiologist, nurse specializing in cardiac rehabilitation, exercise specialist, physical therapist, and clinical nutritionist. All should have an expertise in exercise science and be trained in basic life support or advanced cardiac life support. This statement is a recommendation by KSCR and cardiac rehabilitation council of regional cardiocerebrovascular center, and set forth the standards for facilities, equipment, and staff to set up or upgrade cardiac rehabilitation programs in Korea. These recommendations should be developed as a national standard for the establishment of cardiac rehabilitation programs, and adjusted for the current situation of the Korean medical industry through nationwide and long-term research.

A case involving the use of nafamostat mesilate as an anticoagulant during extracorporeal membrane oxygenation in acute myocardial infarction / 대한내과학회지

It is essential during extracorporeal membrane oxygenation (ECMO) to extend the activated clotting time (ACT) using anticoagulants to prevent blood clot formation. Traditionally, heparin has been used as an anticoagulant during ECMO. Hemorrhaging due to systemic heparinization is considered a major complication of ECMO. A 48-year-old man was admitted due to cardiogenic shock with acute myocardial infarction. ECMO was instituted because of recurrent ventricular tachycardia and refractory shock. We used nafamostat mesilate (Futhan) as an anticoagulant to reduce hemorrhagic complications. The total bypass time was 153 h. The average dose of nafamostat mesilate was 2.64+/-1.11 mg/kg/h; the average ACT was 128.68+/-21.24 seconds. Only a few units were transfused, and there was no oxygenator failure or hemorrhagic complications. Thus, nafamostat mesilate may reduce the need for transfusions and hemorrhagic complications during ECMO.

The Relationship between Arterial Carbon Dioxide Tension and Oxygenator Exhausted Carbon Dioxide Tension during Cardiopulmonary Bypass

BACKGROUND: The neurologic deficit is one of the most serious complications after cardiopulmonary bypass (CPB). This complication has reported to be closely associated with arterial partial pressure of carbon dioxide tension (PaCO2). The traditional way to measure PaCO2 is by intermittent arterial gas analysis during CPB. We tested the relationship between PaCO2 and CPB exhausted partial pressure of carbon dioxide tension (exPCO2) which can be monitored continuously during CPB. METHODS: The total 46 patients who underwent cardiac surgery under CPB were studied. Capnography sampling line was connected to CPB exhausted port to monitor exPCO2. We sampled arterial blood from CPB for gas analysis at cooling, stable hypothermia, and rewarming phase and recorded exPCO2 simultaneously at each phase. RESULTS: We found out that exPCO2 was associated with temperature corrected PaCO2 (cPaCO2) at all 3 phases(r = 0.73, 0.70, 0.84, P < 0.05) and with temperature uncorrected PaCO2 (ucPaCO2) at cooling (r = 0.64, P < 0.05) and rewarming phases (r = 0.81, P < 0.05). CONCLUSIONS: We concluded that exPCO2 could be used to monitor either ucPaCO2 or cPaCO2 at cooling and rewarming phase and cPaCO2 at hypothermia during CPB.

Severe Hypercapnia during Cardiopulmonary Bypass due to Carbon Dioxide Insufflation: A case report / 대한마취과학회지

Air embolization is a potential danger during open heart surgery. To prevent air embolization in incompletely deaired cardiac chambers, flooding of the surgical fields with carbon dioxide (CO2) is used during cardiopulmonary bypass. CO2 flooding may be more useful in de-airing for patients undergoing minimally invasive cardiac surgery. We experienced an episode of sudden, severe hypercapnia and respiratory acidosis in a 51-year-old female patient during hypothermic cardiopulmonary bypass for minimally invasive mitral valve replacement. During hypercapnia, hemodynamic and BIS data were stable except for a slight increase in mean arterial pressure. After ruling out other causes of hypercapnia such as oxygenator failure and malignant hyperthermia, severe hypercapnia disappeared gradually after the cessation of CO2 flooding in the surgical field. No neurologic or cardiopulmonary complications were noted after the operation. We concluded that frequent or continuous CO2 monitoring may be required during CO2 insufflation at surgical fields to prevent hypercapnic complications in minimally invasive cardiac surgery.

Evaluation of bubble oxygen inhalators' performances and an investigation on their solutions for improvement / 中国医疗器械杂志

This paper analyses the defects of bubble oxygen inhalators currently used, and investigates into their solutions for improvement.

Aggressive Surgical Treatment for Complex Cardiac Anomalies Associated with Right Atrial Isomerism / 대한흉부외과학회지

A 3 month old female baby, who had been diagnosed with right atrial isomerism associated with total anomalous pulmonary venous return (TAPVR), a functional single ventricle and major aortopulmonary collateral arteries (MAPCA), underwent left MAPCA unifocalization and left Blalock-Taussig shunt (3.5 mm) at 3 months of age. The postoperative course was complicated by pulmonary venous congestion, and the drainage site of the TAPVR was found to be stenotic on echocardiography. We performed sutureless repair of the TAPVR along with unifocalization of the right MAPCA. She was put on an extracorporeal membrane oxygenator for 8 days after the 2nd operation, and she was able to come off the oxygenator with the placement of a central shunt (3 mm). She developed tracheal stenosis, which was presumably due to longstanding endotracheal intubation, and she then underwent tracheostomy. She was discharged to home on day 104 after the 1st operation, and she has been followed up for 2 months in a good clinical condition.

Corrección de anomálía total del retorno venoso pulmonar en un lactante Testigo de Jehová sin utilización de sangre / Surgical correction of total anomalous venous return in a Jehovah´s witness infant without the use of blood

Los Testigos de Jehová, por razones puramente religiosas, se oponen a la utilización de sangre y sus derivados.Comunicamos la realización de una cirugía cardíaca compleja en un niño pequeño perteneciente esta religión, sin utilizar sangre y sus derivados.Un lactante de 8 meses de edad y 5,4 kg de peso,perteneciente a la religión Testigos de Jehová, con diagnóstico de anomalía total del retorno venosopulmonar en seno coronario e insuficiencia cardíaca refractaria al tratamiento médico fue operado con circulación extracorpórea sin usar sangre o sus derivados, con buena evolución; fue dado de alta sexto día del posoperatorio. El protocolo de trabajo incluyó a) tratamiento preoperatorio con eritropoyetina,hierro y complejos vitamínicos, b) oxigenadorde bajo “priming”, con minimización del circuito extracorpóreo, e) aprotinina intraoperatoria,d) reinfusión de toda la sangre del oxigenador.

Cincuenta años de circulación extracorpórea: la historia de la máquina corazón-pulmón / Fifty years of extracorporeal circulation: the history of the heart-lung machine

Si bien 1953 fue el año del descubrimiento del ADN y de la conquista del Monte Everest, también lo fue de un gran invento tecnológico: la máquina corazón-pulmón, la que ofreció un tratamiento, y en muchos casos cura, a la mayoría de las enfermedades cardiovasculares. En efecto, el 6 de mayo de 1953 John Gibbon logró coronar con el éxito el trabajo de toda su vida al cerrar por primera vez una comunicación interauricular en una joven mujer utilizando una máquina corazón-pulmón de su invención. Sin embargo, previamente la cirugía exploró otros caminos para operar el corazón, como la hipotermia, la que consistía en bajar la temperatura del paciente introduciéndolo en una tina de agua fría para luego efectuar la corrección quirúrgica de una malformación del corazón, en el menor tiempo posible. Por otra parte, luego de su primer éxito, los 4 pacientes siguientes de Gibbon fallecieron, por lo que este abandonó todo intento ulterior, lo que fue seguido por un pesimismo generalizado sobre la circulación extracorpórea. Este fue revertido un año más tarde por Walton Lillehei con la introducción de la "circulación cruzada controlada" en la que un paciente, habitualmente un niño, era conectado a un "donante", habitualmente el padre o la madre, cuyo corazón y pulmón servían como un oxigenador para así efectuar la cirugía a corazón abierto del paciente. Finalmente, es el mismo Lillehei, quien un año más tarde introduce el oxigenador de burbujas, simple y de bajo costo, que abrió las puertas de la cirugía a corazón abierto a todos los cirujanos del mundo. Por esto, para muchos, Walton Lillehei es considerado el "Padre de la Cirugía a Corazón Abierto". Lillehei visitó Chile en 1963 y luego de operar en los pabellones del Hospital Clínico de la Universidad Católica fue nombrado Miembro Honorario de la Facultad de Medicina de dicha Universidad. Previamente, en 1957, Helmuth Jaeger había efectuado el primer cierre quirúrgico exitoso de una comunicación interauricular con circul...

Effect of Retrograde Autologous Priming in Adult Cardiac Surgery for Minimizing Hemodilution and Transfusion Requirements / 대한흉부외과학회지

BACKGROUND: Hemodilution after priming of the cardiopulmonary bypass is known to increase the possibility of bleeding and homologous transfusion in adult cardiac surgery. We investigated the effects of retrograde autologous priming (RAP) to see whether it would decrease postoperative bleeding and homologous transfusion. MATERIAL AND METHOD: We retrospectively reviewed 34 patients wpho underwent RAP and 46 patients who did not. Retrograde autologous priming consisted of arterial line drainage, venous reservoir and oxygenator drainage and venous line drainage. We compared the amount of priming solution and RAP volume, perioperative hematocrit, postoperative bleeding and transfusion requirements in the two groups. RESULT: Mean withdrawal volume in RAP group was 613.5+/-160.6 mL and initial priming volume was 1381.9+/-37.2 mL. Hemoatocrits (%) in RAP and control groups were 25.0+/-3.7 vs 20.9+/-3.6 (5 minutes after CPB), 25.9+/-3.7 vs 22.5+/-3.6 (30 minutes after CPB), 25.9+/-3.4 vs 23.8+/-2.8 (60 minutes after CPB), 31.9+/-3.9 vs 31.5+/-4.5 (postoperative 1 hour), 32.4+/-4.4 vs 32.1+/-4.5 (postoperative 6 hours), 33.4+/-5.0 vs 31.7+/-5.1 (postoperative 1 day)[repeated measures ANOVA, p<0.05]. Chest tube drainages (mL) in the two groups were 357.2+/-177.1 vs 411.7+/-279.5 (postoperative 6 hours), 599.4+/-145.6 vs 678.8+/-256.4 (postoperative 24 hours)[t-test, p<0.05]. Homologous transfusion was performed in 7 out of 34 patients in RAP group (20.6%), and 16 out of 46 (34.8%) in control group (p<0.05). CONCLUSION: This study suggests that the effects of reducing the priming volume during cardiopulmonary bypass may result in lesser bleeding and homologous transfusion. Retrograde autologous priming would be used to reduce postoperative bleeding and chance of transfusion after adult cardiac surgery.

Use of Undiluted Potassium Solution in Intermittent Antegrade Warm Blood Cardioplegia (IAWBC) / 대한흉부외과학회지

BACKGROUND: Dilution of blood cardioplegia is not needed in IAWBC as it is in cold blood cardioplegia because it does not aggregate red blood cells on normal body temperature and does not compromise micro coronary circulation. This study was designed to evaluate the safety and efficacy of undiluted potassium solution in IAWBC. MATERIAL AND METHOD: Thirty patients who underwent CABG with IAWBC were grouped into dilutedplegia (n=14) and microplegia (n=16). Potassium was delivered conventionally with 4:1 delivery kit in the dilutedplegia group. The undiluted potassium was directly connected on the blood of oxygenator in the microplegia group. RESULT: There were no differences in sex, age, left ventricular ejection fraction, number of grafts, aortic cross clamping time, and the value of perioperative myocardial enzyme between the two groups. There were no perioperative myocardial infarction and hospital mortality. The amount of crystalloid cardioplegia was 1346+/-597 mL in dilutedplegia (mean+/-standard deviation, and 28+/-9 mL in microplegia (p0.05). 11 patients in dilultedplegia received blood transfusion, but 4 patients in microplegia received blood transfusion (p<0.05). The amount of urine and hemofiltration during the operation were more in dilutedplegia (1250+/-810 mL, 1689+/-548 mL) than in microplegia (959+/-410 mL, 1481+/-784 mL; p<0.05). CONCLUSION: The undiluted potassium of IAWBC in CABG operation is a safe, effective technique for myocardial protection to prevent fluid overload, and blood transfusion. There is no need to use the delivery kit.

Establishment of Featal Heart Surgery with an Improvement of the Placental Blood Flow in Cardiopulmonary Bypass Using Fetal Lamb Model / 대한흉부외과학회지

BACKGROUND: We tested the effect of indomethacine and total spinal anesthesia on the improvement of placental flow during cardiopulmonary bypass on fetal lamb. MATERIAL AND METHOD: Twenty fetuses at 120 to 150 days of gestation were subjected to bypass via trans-sternal approach with a 12 G pulmonary arterial cannula and 14 to 18 F venous cannula for 30 minutes. All ewes received general anesthesia with ketamine. In all the fetuses, no anesthetic agents were used except muscle relaxant. Ten served as a control group in which placenta was worked as an oxygenator during bypass (Control group). The remainder worked as an experimental group in which pretreatment with indomethacine and total spinal anesthesia was performed before bypass with the same extracorporeal circulation technique as control group (Experimental group). Observations were made every 10 minutes during a 30-minute bypass and 30-minute post bypass period. RESULT: Weights of the fetuses ranged from 2.2 to 5.2 kg. In Control group, means of arterial pressure decreased from 44.7 to 14.4 mmHg and means of PaCO2 increased from 61.9 to 129.6 mmHg at each time points during bypass. Flow rate was suboptimal (74.3 to 97.0 ml/kg/min) during bypass. All hearts fibrillated immediately after the discontinuation of bypass. On the contrary, in Experimental group, means of arterial pressure reamined higher (45.8 to 30 mmHg) during bypass (p<0.05). Means of PaCO2 were less ranging from 59.8 to 79.4 mmHg during bypass (p<0.05). Flow rates were higher (78.8 to 120.2 ml/ kg/min) during bypass (p<0.05). There were slower deterioration of cardiac function after cessation of bypass. CONCLUSION: In this study, we demonstrated that the placental flow was increased during fetal cardiopulmonary bypass in the group pretreated with indomethacine and total spinal anesthesia. However, further studies with modifications of the bypass including a creation of more concise bypass circuit, and a use of axial pump are mandatory for the clinical application.

A Comparison of Carbon Dioxide Tensions between Arterial Blood and Oxygenator Exhaust Gas during Cardiopulmonary Bypass / 대한마취과학회지

BACKGROUND: Maintenance of adequate concentration of carbon dioxide during hypothermic cardiopulmonary bypass is important in order to improve tissue perfusion by maintaining vasodilatation. This study evaluated the usefulness of the analysis of gas sampled from the exhaust port of a membrane oxygenator in the estimation of carbon dioxide tension in arterial blood (PaCO2). METHODS: One hundred sixty four arterial blood gases were drawn from 45 adult and 30 pediatric cardiac surgical patients undergoing hypothermic cardiopulmonary bypass. Carbon dioxide tensions were measured in the membrane oxygenator exhaust gas (swept gas; PswCO2) using a capnography and in arterial blood using intermittent gas analysis. We compared the PswCO2 with temperature-uncorrected (alpha-stat) and -corrected (pH-stat) PaCO2 during cardiopulmoary bypass. RESULTS: The mean PaCO2 measured with alpha-stat and pH-stat, and PswCO2 obtained in adult patients during hypothermic cardiopulmonary bypass were 29.8 +/- 4.9, 19.5 +/- 4.1 and 22.3 +/- 4.2 mmHg, respectively. In pediatric patients, alpha-stat PaCO2, pH-stat PaCO2 and PswCO2 were 39.7 +/- 7.7, 24.7 +/- 6.2 and 20.3 +/- 6.0 mmHg, respectively. There was a significant positive correlation between PswCO2 and alpha-stat PaCO2 (adult patients: slope = 0.49, r = 0.64, P < 0.001; pediatric patients: slope = 0.53, r = 0.68, P < 0.001) and pH-stat PaCO2 (adult patients: slope = 0.85, r = 0.81, P < 0.001; pediatric patients: slope = 0.73, r = 0.73, P < 0.001). On comparison of subsequent measurements, 3.8% (adult patients) and 11.4% (pediatric patients) of changes in PaCO2 and PswCO2 were in opposite direction. CONCLUSIONS: Our results indicate that in adult and pediatric patients undergoing hypothermic cardiopulmonary bypass PswCO2 can be an indicator of changes in trend of PaCO2.