Before beginning the extracorporeal circulation, perfusionists should supply oxygen into the oxygenator and establish blood flow through the blood line of the heart-lung machine. But these manipulation can induce severe hypocarbic state of priming solutions due to wash out of CO2 gas in the solution. This study was carried out to examine the relationship of blood gas changes between hypocarbic priming solutions and body circulation in 15 patients undergoing open heart surgery with extracorporeal circulation. PaCO₂, pH, buffer base and PaO2 were measured from priming solutions before and 15 minutes after the extracorporeal circulation. The results were as follows; 1) Before the extracorporeal circulation, mean PaCO₂ level was 12.1±7.8 mmHg in the priming solution. However, 15 minutes after extracorporeal circulation, the PaCO₂ level was maintained at 35.7±5.7 mmHg. 2) pH in the priming solution was variable from 6.93 to 7.99 (mean 7.45±0.29), but after 15 minutes it was ranged from 7.28 to 7.42 (mean 7.35±0.05). 3) Mean buffer base level in the priming solution was 7.9±3.5 mmol/l. but after 15 minutes, it was 19.6±1.2 mmol/l. 4) Mean PaO₂ level in the priming solution was 667.1±45.6 mmHg, but after 15 minutes, it was 280.7±131.7 mmHg.
Extracorporeal Circulation* ; Heart* ; Heart-Lung Machine ; Humans ; Hydrogen-Ion Concentration ; Oxygen ; Oxygenators ; Thoracic Surgery*

A hypothermic, low flow perfusion, using 5% dextrose in water as the priming fluid in the pump-oxygenator, was carried out to observe oxygen consumption, blood pH changes, and CO2 tension during the bypass period. A low oxygen consumption which was approximately one third of the preperfusion value, was observed during the total by-pass period. This is believed to be due to the effect of low flow rates employed, hypothermia and low CO2 tension observed in these animals. The pH of the arterial blood and the partition of the total CO2 remained within a fairly normal range. There was a marked reduction in CO2 tension during the bypass period. Its harmful effect on the oxyhemoglobin dissociation curve and cerebral circulation was discussed. The hemodilution attendant to the use of 5% dextrose in water as the priming fluid is considered insignificant.
Animals ; Dogs ; Glucose/*adverse effects ; *Heart-Lung Machine ; *Hypothermia, Induced ; Plasma Substitutes/*adverse effects

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

BACKGROUND: High-dose aprotinin appears to enhance the anticoagulant effects of heparin, as documented by increases in the activated clotting times (ACTs) during cardiopulmonary bypass. This increase of the ACT in the presence of aprotinin and heparin is due to the use of celite as surface activator. We compared celite and kaolin as surface activators for the measurement of the ACT in cardiac surgical patients treated with high dose aprotinin. METHODS: This study included 25 patients who were scheduled for coronary bypass graft surgery and reoperation of cardiac valvular surgery. The 2 million units of aprotinin were added to the pump prime of heart-lung machine. The dosage of heparin and protamine was 3 mg/kg respectively. Whole blood was sampled 10 minutes after induction, heparin administration, cardiopulmonary bypass(CPB), 10 minutes before the termination of CPB and 10 minutes after protamine administration. The ACT was measured with Hemochron 801 blood coagulation timer with 12 mg of either celite (C-ACT) or kaolin (K-ACT) used as surface activator. RESULTS: At 10 minutes after induction and heparin administration, celite and kaolin ACTs were l20+/-28, 541+/-247 seconds and 126+/-23, 559+/-267 seconds rcspectively. But 10 minutes after initiation of CPB and before the termination of CPB, celite ACTs were 941+/-238 and 787+/-277 seconds; kaolin ACTs were 605+/-182 and 499+65 seconds, which were consistently less than celite ACTs(p<0.01). At 10 minutes after protamine administration, celite ACT was 118+/-12 seconds and kaolin ACT was 142 56 seconds which was consistently more than celite ACT(p<0.05). CONCLUSIONS: We recommend the K-ACT rather than C-ACT when monitoring of heparin-induced anticoagulation in patients treated with high-dose aprotinin. It is also highly recommended that patients being added with aprotinin should receive the usual doses of heparin and that the ACT should be measured with kaolin as the activator.
Aprotinin* ; Blood Coagulation ; Cardiopulmonary Bypass ; Diatomaceous Earth* ; Heart-Lung Machine ; Heparin ; Humans ; Kaolin* ; Reoperation ; Thoracic Surgery* ; Transplants

BACKGROUND: High-dose aprotinin appears to enhance the anticoagulant effects of heparin, as documented by increases in the activated clotting times (ACTs) during cardiopulmonary bypass. This increase of the ACT in the presence of aprotinin and heparin is due to the use of celite as surface activator. We compared celite and kaolin as surface activators for the measurement of the ACT in cardiac surgical patients treated with high dose aprotinin. METHODS: This study included 25 patients who were scheduled for coronary bypass graft surgery and reoperation of cardiac valvular surgery. The 2 million units of aprotinin were added to the pump prime of heart-lung machine. The dosage of heparin and protamine was 3 mg/kg respectively. Whole blood was sampled 10 minutes after induction, heparin administration, cardiopulmonary bypass(CPB), 10 minutes before the termination of CPB and 10 minutes after protamine administration. The ACT was measured with Hemochron 801 blood coagulation timer with 12 mg of either celite (C-ACT) or kaolin (K-ACT) used as surface activator. RESULTS: At 10 minutes after induction and heparin administration, celite and kaolin ACTs were l20+/-28, 541+/-247 seconds and 126+/-23, 559+/-267 seconds rcspectively. But 10 minutes after initiation of CPB and before the termination of CPB, celite ACTs were 941+/-238 and 787+/-277 seconds; kaolin ACTs were 605+/-182 and 499+65 seconds, which were consistently less than celite ACTs(p<0.01). At 10 minutes after protamine administration, celite ACT was 118+/-12 seconds and kaolin ACT was 142 56 seconds which was consistently more than celite ACT(p<0.05). CONCLUSIONS: We recommend the K-ACT rather than C-ACT when monitoring of heparin-induced anticoagulation in patients treated with high-dose aprotinin. It is also highly recommended that patients being added with aprotinin should receive the usual doses of heparin and that the ACT should be measured with kaolin as the activator.
Aprotinin* ; Blood Coagulation ; Cardiopulmonary Bypass ; Diatomaceous Earth* ; Heart-Lung Machine ; Heparin ; Humans ; Kaolin* ; Reoperation ; Thoracic Surgery* ; Transplants

OBJECTIVES: Clinical Practice Guidelines (CPGs) are an effective tool for minimizing the gap between a physician's clinical decision and medical evidence and for modeling the systematic and standardized pathway used to provide better medical treatment to patients. METHODS: In this study, sentences within the clinical guidelines are categorized according to a classification system. We used three clinical guidelines that incorporated knowledge from medical experts in the field of family medicine. These were the seventh report of the Joint National Committee (JNC7) on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure from the National Heart, Lung, and Blood Institute; the third report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults from the same institution; and the Standards of Medical Care in Diabetes 2010 report from the American Diabetes Association. Three annotators each tagged 346 sentences hand-chosen from these three clinical guidelines. The three annotators then carried out cross-validations of the tagged corpus. We also used various machine learning-based classifiers for sentence classification. RESULTS: We conducted experiments using real-valued features and token units, as well as a Boolean feature. The results showed that the combination of maximum entropy-based learning and information gain-based feature extraction gave the best classification performance (over 98% f-measure) in four sentence categories. CONCLUSIONS: This result confirmed the contribution of the feature reduction algorithm and optimal technique for very sparse feature spaces, such as the sentence classification problem in the clinical guideline document.
Adult ; Cholesterol ; Data Mining ; Heart ; Humans ; Hypertension ; Information Storage and Retrieval ; Joints ; Knowledge Bases ; Learning ; Lung ; Machine Learning

To observe the erythrocyte fragility and morphological changes of erythrocytes caused by roller pump. Ten tests were divided into two groups, Polystan pediatric pump group A (n = 5) and COBE pump group B (n = 5). Ten whole blood samples (each 400 ml) were circulated in the roller pump for 16 h. Erythrocyte fragility and free hemoglobin were measured before pumping and at every 2 hours during pumping. The possible morphological changes of erythrocytes caused by roller pump were observed by scanning electron microscope. The electron microscopic observation was made before pumping and at every 4 hours throughout pumping. Results showed that the erythrocyte fragility of two groups was not increased during a long period of pumping. The number of acanthocytes of two groups was 1.77/1.81% in the samples before pumping and 6.12/7.13, 9.18/8.73, 13.21/12.89, 16.53/17.21% at 4 h, 8 h, 12 h, and 16 h respectively. The free hemoglobin level of two groups was increased linearly during a long duration of pumping and the index of hemolysis of two groups was 0.296 mg/L/h and 0.3993 mg/L/h respectively. The result shows: 1. the erythrocyte fragility was not increased during a long period of pumping; 2. the erythrocyte membrane was injured or broken by roller pump directly; 3. the morphological changes of erythrocytes would be the basis of post operative hemolysis.
Erythrocyte Deformability ; Heart-Lung Machine ; adverse effects ; Hemoglobins ; analysis ; Hemolysis ; Humans ; In Vitro Techniques ; Osmotic Fragility ; Time Factors

Extracorporeal membrane oxygenation (ECMO) is a technique that uses a pump to drain blood from a body, circulate blood through a membrane lung, and return the oxygenated blood back into the body. Venoarterial (VA) ECMO is a simplified version of the heart-lung machine that assists native pulmonary and/or cardiac function. VA ECMO is composed of a drainage cannula in the venous system and a return cannula in the arterial system. Because VA ECMO can increase tissue perfusion by increasing the arterial blood flow, it is used to treat medically refractory cardiogenic shock or cardiac arrest. VA ECMO has a distinct physiology that is referred to as differential flows. It can cause several complications such as left ventricular distension with pulmonary edema, distal limb ischemia, bleeding, and thromboembolism. Physicians who are using this technology should be knowledgeable on the prevention and management of these complications. We review the basic physiology of VA ECMO, the mechanism of complications, and the simple management of VA ECMO.
Catheters ; Drainage ; Extracorporeal Membrane Oxygenation ; Extremities ; Heart Arrest ; Heart-Lung Machine ; Hemorrhage ; Ischemia ; Lung ; Membranes ; Oxygen ; Perfusion ; Physiology ; Postoperative Complications ; Pulmonary Edema ; Shock ; Shock, Cardiogenic ; Thromboembolism

After the heart-lung machine was used for the open heart surgery, it was hypothesized that the extracorporeal circulation might be applicable to the management of acute respiratory failure. The development of silicone membrane minimized the possible physical or chemieal damages to blood perfused into the oxygenator. Extracorporeal lung assist(ECLA) using a membrane oxygenator has been recognized as a therapeutic modality for acute respiratory failure, To simplify and reduce the voulme of the ECLA circuit, a small oxygenator, surface area 0.3 m2, was developed by Kurare Co., Japan. It was composed of non-microporous hollow fibers. We performed venoarterial(VA) ECLA to evaluate the gas transfer of the Kurare oxygenator. The priming volume of the ECLA circuit was about 150 ml. Venous blood was drained via the right external jugular vein. The maximum bypass flow rate was about l060 ml/min. Oxygenated blood was perfused into aortic arch via the right carotid artery. The increase of arterial oxygen tension was about 58 mmHg during VA ECLA. It was confirmed that Kurare oxygenator was adequate for the oxygenation support on hypoxic dogs. We tried this ECLA circuit on a postoperative cardiac patient on May, 20, 1991. After 90 hours VA ECLA, she recovered without any complicatioris.
Animals ; Aorta, Thoracic ; Carotid Arteries ; Dogs* ; Extracorporeal Circulation ; Heart-Lung Machine ; Humans ; Japan ; Jugular Veins ; Lung* ; Membranes* ; Oxygen ; Oxygenators ; Oxygenators, Membrane* ; Respiratory Insufficiency ; Silicones ; Thoracic Surgery

A 63 Year-old-lady has had substernal chest pain on exertion for 8 years. The chest pain has been increased over the last 3 years. A continuous murmur was heard at the left second to third inercostal spaces along the left sternal border. The electrocardiogram showed the inverted T-waves in the precordial leads. The right heart catheterization revealed 5% oxygen step up between RV and PA. The right sided pressures were normal. The coronary arteriography revealed markedly tortuous vessels starting shortly after the left main stem coronary artery was normally originated. One of the large vessel was shown to be drained into the pulmonary artery. In the operation room, without using heart-lung machine this abnormally drained vessel was simply ligated at it's draining site into pulmonary artery. After the operation the patient is feeling well with little symptoms and the continuous murmur is no longer heard.
Angiography ; Arteriovenous Fistula* ; Cardiac Catheterization ; Cardiac Catheters ; Chest Pain ; Coronary Vessels* ; Electrocardiography ; Heart-Lung Machine ; Humans ; Middle Aged* ; Oxygen ; Pulmonary Artery*