No abstract available.
Oxygen* ; Oxygenators*

This paper analyses the defects of bubble oxygen inhalators currently used, and investigates into their solutions for improvement.
Oxygen Inhalation Therapy ; instrumentation ; methods ; Oxygenators ; standards

In order to evaluate causes and the effective treatment of postoperative bleeding after open heart surgery, we measured platelet count and plasma fibrinogen levels before, during a 30 and 60-minute, and after a 30, 60 and 90-minute extracorporeal circulation in 5 patients perfused by a bubble and membrane oxygenator, respectively. The results were as follows: 1) The platelet count was reduced significantly by 57.2+/-3.04% during a 30-minute extracorporeal circulation using the bubble oxygenator and by 43.8+/-0.84% using the membrane oxygenator, and these levels were maintained throughout the extracorporeal circulation. 2) The platelet count after a 90-minute extracorporeal circulation increased significantly compared with after a 30-minute extracorporeal circulation (p<0.05) and these effects were more prominent using the bubble oxygenator (p<0.025). 3) The plasma fibrinogen level was reduced by 28.6+/-7.50% during a 30-minute extracorporeal circulation using the bubble oxygenator and by 33.6+/-5.77% using the membrane oxygenator, and these levels were maintained throughout the extracorporeal circulation. 4) The plasma fibrinogen level after a 90-minute extracorporeal circulation increased significantly compared with after a 30-minute extracorporeal circulation (p<0.05).
Blood Platelets* ; Extracorporeal Circulation* ; Fibrinogen* ; Hemorrhage ; Humans ; Oxygen ; Oxygenators ; Oxygenators, Membrane ; Plasma* ; Platelet Count* ; Thoracic Surgery

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.
Adult ; Capnography ; Carbon Dioxide* ; Carbon* ; Cardiopulmonary Bypass* ; Gases ; Humans ; Oxygen* ; Oxygenators* ; Oxygenators, Membrane ; Perfusion ; Vasodilation

The changes in arterial carbon dioxide tension (PaCO2) during cardiopulmonary bypass reflect changes of temperature and gas flow through an oxygenator. The changes in PaCO2 can be reduced through the frequent analysis of arterial blood gases and subsequent adjustment of total gas flow and CO2 concentration in the gas flow or both. Utilizing a capnometer (CAPNOMAC AGM-103. Datex), we compared end-tidal carbon dioxide tension (PetCO2) from the capnometer with temperature corrected PaCO2 during cardiopulmonary bypass. One end of the sampling port of the capnometer was incorporated into the prime port of the arterial reservoir in a bubbling type oxygenator (William-Harvey). When arterial reservoir temperatures of the oxygenator were 30 degrees C and 35 degrees C, PetCO2 from the capnometer was recorded and two arterial blood gas samplings were done at the same temperatures. The results were as follows: 1) The difference of PetCO2 and temperature corrected PaCO2 was below 3 mmHg in all cases. 2) The relationship between PetCO2 and temperature corrected PaCO2 was significantly linear. The results show that continuous monitoring of PetCO2, using a capnometer is useful to control the changes in PaCO2 during cardiopulmonary bypass.
Carbon Dioxide* ; Carbon* ; Cardiopulmonary Bypass* ; Gases ; Oxygen ; Oxygenators

The influence of isoflurane on systemic vascular resistances was studied during total cardiopulmonary bypass with membrane oxygenator, low rate of 2.4 L/min/m(2) and moderate hypothermia Data were obtained from 40 adult patients undergoing corrective surgery for congenital or aquired heart disease. The materials were randomly divided in two groups with 20 and 20 patients, respectively, Before cadiopulmonary bypass, the same anesthetic technique was applied to 2 groups. During cardiapuhnonary bypass, isoflurane was given into oxygenator at 0.5-1.5% concentration in group I. In group II, no isoflurane was given but 0.2 mg/kg midazolam was supplied into the oxygenator at the beginning of bypass. To both groups small amounts of fentanyl were given during bypass. There were no significant differences in mean cardiopulmonary bypass time and pump flow between the groups.In group I, systemic vascular resistance did not increase until 60 minutes, whereas in group II systemic vascular resistance increased significantly after 30 minutes and maximal increase was noticed at 60 minutes. Data for base excess demonstrated that significant fall after 40 minutes of perfusion in group II, but not changes in group I. It is concluded that isoflurane exerts a beneficial vasodilatory action during caardiopulmonary bypass and hypothermia. And the harzards of local reduction in organic blood flow are ehminated, because an adequate perfusion pressure and flow are maintained by the heart lung machine.
Adult ; Cardiopulmonary Bypass* ; Fentanyl ; Heart Diseases ; Heart-Lung Machine ; Humans ; Hypothermia ; Isoflurane* ; Midazolam ; Oxygen ; Oxygenators ; Oxygenators, Membrane ; Perfusion ; Vascular Resistance

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.
Adult ; Anticoagulants ; Cause of Death ; Critical Illness ; Extracorporeal Membrane Oxygenation ; Humans ; Membranes ; Oxygen ; Oxygenators ; Oxygenators, Membrane ; Pediatrics ; Salvage Therapy

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.
Arteries ; Drainage ; Echocardiography ; Extracorporeal Membrane Oxygenation ; Female ; Heterotaxy Syndrome* ; Humans ; Hyperemia ; Infant ; Intubation, Intratracheal ; Oxygen ; Oxygenators ; Oxygenators, Membrane ; Scimitar Syndrome ; Tracheal Stenosis ; Tracheostomy

BACKGROUND: Intrauterine surgical intervention for certain cardiac anomalies may have a therapeutic advantage over postnatal repair or palliation. However, it is essential to establish methods for intrauterine extracorporeal circulation and myocardial preservations which can maintain the hemodynamics and gas exchange in fetal lamb perioperatively. This study was aimed to observe the changes in hemodynamics and gas exchange according to the methods of fetal cardiac bypass. METHODS: Twelve fetal lambs (4.5 5.2 kg) at 120 to 150 days of gestation under ketamine anesthesia were subjected to cardiac bypass for 30 minutes. Six served as a group in which placenta was excluded from the extracorporeal circulation by clamping the umbilical cord during the bypass (the oxygenator group) and in the remaining six, the placenta worked as an in vivo oxygenator (the placenta group). The fetuses were observed every 10 minute during a 30-minute bypass and 30-minute post bypass period. The hemodynamic variables and fetal blood gases were measured at specific intervals. RESULTS: In the oxygenator group, mean arterial pressure (MAP), PaO2, heart rate and bypass flow rate were 62 to 74 mmHg, 220 to 282 mmHg, 169 to 182 /min and 134 to 164 ml/kg/min, respectively during bypass. But rapid deterioration of fetal cardiac and placental gas exchange function was observed following cessation of bypass. In the placenta group, MAP decreased from 61 to 34 mmHg and PaCO2 progressively increased from 56 to 74 mmHg during bypass. Flow rate was suboptimal (74 to 115 ml/kg/min) during bypass. All hearts of the placenta group was fibrillated immediately after discontinuation of bypass. CONCLUSION: The both methods of CPB, use of oxygenator and placenta as gas exchanger, under only ketamine anesthesia did not provide adequate hemodynamics and gas exchange without additional treatment for protection placental reaction. The methods of fetal cardiac bypass using either neonatal membrane oxygenator or placental as an in vivo oxygenator caused severe placental dysfunction and blood gas abnormalities.
Anesthesia* ; Arterial Pressure ; Constriction ; Extracorporeal Circulation ; Fetal Blood ; Fetus ; Gases ; Heart ; Heart Rate ; Hemodynamics* ; Ketamine* ; Oxygen ; Oxygenators ; Oxygenators, Membrane ; Placenta ; Pregnancy ; Umbilical Cord

The extracorporeal membrane oxygenation(ECMO) for acute respiratory distress, syndrome was started in Korea from 1990. Until now there were 4 clinical cases in Korea. Three cases were cardiac patients who received the open heart surgery and one was lung contusion patient by a automobile accident. Among them one case survived after 90 hours ECMO and became the first successful ECMO case in Korea and also the first in Asia except Japan. In this case we used new anticoagulant nafamostat mesilate in order to reduce the subcutaneous bleeding. All the oxygenators were membrane type. The last one was the heparin-bonded microporous membrane type which was made for the cardiopulmonary bypass of open heart surgery. The last case showed the possibility of the use of microporous membrane oxygenator for prolonged extracorporeal membrane oxygenation without administration of the anticoagulation. We believe that the ECMO will become popular as a prolonged life supporting method in near future in Korea.
Asia ; Automobiles ; Cardiopulmonary Bypass ; Contusions ; Extracorporeal Membrane Oxygenation* ; Heart* ; Hemorrhage ; Humans ; Japan ; Korea ; Lung* ; Membranes ; Mesylates ; Oxygen ; Oxygenators ; Oxygenators, Membrane ; Thoracic Surgery