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At least 19 recordsLinked to original sources
PubMedDate not supplied

Hypopotassemia following open heart surgery by cardio-pulmonary bypass.

1. In this study where potassium concentration of perfusate of heart-lung machine was made high and no potassium was given until two hours after by-pass, the fall of plasma potassium level due to heart-lung bypass occurred in two stages, namely one hour of complete bypass and two hours after the end of bypass. 2. Regarding to the decrease of these plasma potassium level, increase of potassium excretion into urine and the movement of potassium from extracellular fluid into cells are presumed to be causes. Their genesis was discussed. 3. To prevent hypopotassemia following bypass, it is recommended to add KCl in the perfusate of heart-lung machine and to give intravenous drip of KCl immediately after bypass.

Blood Glucose↗
PubMed1975

Clinical evaluation of priming solutions for pump oxygenator perfusion.

Various hemodilution agents are now used routinely to prime heart-lung machines for cardiac operations. Hemodilution has resulted in considerable conservation of blood as well as diminution of plasma and corpuscle damage by decreasing the concentration of these elements in blood during extracorporeal circulation. Controversy has existed regarding the relative efficacy of various hemodilution solutions. This study covers 68 patients, divided into three groups, for whom hemodilution was done as follows: (1) the pump was primed with a 5% dextrose solution containing no colloid; (2) Ringer's lactate solution containing approximately 1% low-molecular-weight dextran was used; and (3) a new plasma expander, hydroxyethyl starch, was used as the colloid component of an electrolyte solution. Evaluations and comparisons were carried out for flow rates, blood pressure, urine volume, hematocrit, BUN, blood loss, clotting factors, and the patient's clinical course with regard to pulmonary and neurological complications. We conclude that a colloid is beneficial, especially with longer perfusions.

Adolescent↗
PubMed1978

Effects of stored and fresh blood transfusions on postoperative pulmonary function. A clinical study on patients following extracorporeal circulation in association with aortic valve surgery.

The effects on postoperative pulmonary function of fresh versus stored blood when priming the heart-lung machine were studied in 49 patients subjected to aortic valvular replacement. The onset of extracorporeal circulation was considered to mimic the conditions of massive blood transfusion. The patients receiving heparinized fresh blood required more oxygen in the respirator than those receiving stored blood, but still had a significantly lower arterial oxygen tension during the first and second postoperative days. The fresh blood patients also showed a tendency to require a larger amount of diuretics to maintain adequate urine output. Pre- and postoperative bleeding and changes in postoperative hematological variables did not differ in the two groups. The results imply that stored blood should be preferable when substituting blood losses.

Aortic Valve↗
PubMed1976

[Membrane oxygenators in cardiac surgery: progress].

This study tries to define if the membrane oxygenators are available during cardiac surgery under E.C.C., and if their performance are superior to those of conventional oxygenators. Two series of research are done. In the first one, we compare performance of two membrane oxygenators: the Rhône-Poulenc heart-lung machine (10 cases) and the Travenol TMO Teflo machine (100 cases). The general impression is good: the two proposed systems seem to be perfectly well adapted to surgical utilization conditions, avoiding excessive ventilations and eventually allowing to keep on E.C.C. in postoperative. In the second part of this work, two series of patients are studied, one oeprated under membrane oxygenator (Teflo), the second under bubble oxygenator (Bentley Q 100). Comparative study shows small differences between the two groups. Only the post-operative enzymatic profile is clearly for the membrane oxygenator which also insure a waking and a postoperative recovery of highest quality. These first observations justify to keep on using of membrane oxygenators in cardiac surgery.

Cardiac Surgical Procedures↗
PubMed1975

[Studies on extracorporeal circulation with large volume hemodilution using lactate ringer's solution and low molecular weight dextran: alterations of acid-base balance associated with intentional hemodilution (author's transl)].

Twenty mongrel dogs, weighing between 7.5 and 13.0 kg were used to investigate the percentage limits permissible for hemodilution using a double-helical reservoir heart-lung machine which has a 1,100 ml of priming volume. In both 40 and 50 per cent groups of intentional hemodilution by 30 minute extracorporeal circulation, remarkable anemia was inevitable and recovery was extremely slow, especially in the 50 per cent dilution group. In both 40 and 50 per cent groups of intentional hemodilutions by 30 minute extracorporeal circulation, metabolic acidosis was observed. In 50 per cent group of intentional hemodilution, no improvement of metabolic acidosis was observed even after perfusion. When sodium bicarbonate was administered to 40 per cent hemodilution group, minimum alterations of acid-base balance and of serum electrolytes were observed during and after extracorporeal perfusion. When sodium bicarbonate was administered to 50 per cent hemodilution group, metabolic acidosis was more evident than in 40 per cent hemodilution group accompanied with an increase in serum sodium concentration and a decrease in serum chloride concentration. These data qualify the use of 40 per cent intentional hemodilution using Lactate Ringer's solution or low molecular weight dextran for 30 minute extracorporeal circulation when sodium bicarbonate is administered in adequate amounts.

Acid-Base Equilibrium↗
PubMed1976

A Dacron wool packed-bed extracorporeal reactor: a kinetic study of immobilized Escherichia coli II L-asparaginase.

An extracorporeal reactor containing a packed bed of Dacron fibers has been developed. Escherichia coli II L-asparaginase was coupled to the Dacron using gamma-aminopropyltriethoxysilane and glutaraldehyde. The preparation had an activity of 37 IU per gram of Dacron (37 degrees C). The apparent Km was studied as a function of the flow rate. The data indicated that the apparent Km approached the Km of the native enzyme at flow rates of about 300 mg/min. In vivo use of L-asparaginase immobilized on the Dacron indicated effective lowering of plasmatic L-asparagine levels.

Animals↗
PubMed1976

Ultrastructure of mitochondria-containining nuclei in human myocardial cells.

The ultrastructure of myocardial cell nuclei was examined in a group of 12 patients undergoing cardiopulmonary bypass surgery. In one patient (aged 60 years) with rheumatic heart disease, myocardial cells were observed which contained mitochondria with well preserved membranes within their nuclei. Such intranuclear mitochondria were observed with equal frequency in all of the three stages examined, i.e. at the start and end of aortic crossclamping and after 20 min of reperfusion. Approximately 2-3% of the total number of nuclei studied in this patient contained mitochondria. A partial disintegration of the membranes of the affected nuclei was sometimes seen. These findings are discussed in relation to the hypothesis of a de novo synthesis of mitochondria inside the nucleus, and also, in relation to the "trapping theory" of mitochondria through the nuclear envelope.

Biopsy↗
PubMed1976

Accidental hypothermia: core rewarming with partial bypass.

Three patients with profound hypothermia were treated by rewarming on partial bypass. Two surivived and have normal mental and metabolic functions. The resuscitation of the hypothermic patient should be approached with enthusiasm since the outcome is often much better than expected from initial vital signs and neurologic examination. To avoid ventricular fibrillation the patient should be handled gently and an effort should be made to keep the patient well oxygenated and the pH normal. Blood gases should be measured often and corrected for temperature. The potassium concentration and hydration status of the patient should also be monitored closely. The rewarming of profoundly hypothermic patients can readily be accomplished with a pump oxygenator and heat exchanger. The indications for this method are not established from our small experience and the few cases reported in the literature. Certainly ventricular fibrillation is a compelling indication. Patients with frozen extremities might also benefit from this method since theoretically tissue salvage would be increased. Finally, those patients who do not respond rapidly to external rewarming may be at less risk of ventricular fibrillation if rewarmed on bypass.

Accidents↗
PubMed1975

Hydraulic studies of aortic cannulation return nozzles.

An in vitro investigation of 8 different types of clinical aortic return nozzles was conducted. The importance of cannula geometry, tip location and direction was demonstrated in preventing abnormal flow conditions in the major aortic arch arteries. Alternative methods to correct these abnormalities were studied. This report has presented a preliminary study of the flow conditions produced by aortic cannulae during cardiopulmonary bypass. More detailed analysis of the pressure field as well as in vivo studies of the effects of a non-rigid geometry of the flow behavior are needed to confirm the findings of this investigation.

Aorta↗
PubMed1975

[Studies on low volume priming heart lung bypass (author's transl)].

This report concerns the feasibility of low volume priming extracorporeal circulation. Through this study, the bubble oxygenator with Zuhdi's heat exchange was used. Moderate hypothermia with surface cooling and hemodilution perfusion with 5 per cent D/W was evaluated in 32 mongrel dogs and 16 clinical open heart cases. The results obtained here were as follow: 1) Body temperature reduction by surface cooling before bypass provided more even cooling than did core cooling by low flow partial bypass alone. 2) In regard to cardiac loading on returning the whole perfusate of the circuit to patient, approximately 20 ml/kg of 5 per cent D/W was feasible as a priming solution. 3) To reduce the blood visicosity, hemodilution technique with 5 per cent D/W was superior, and hemodilution effect during postoperative periods was temporaly. 4) The excess lactate volume postulated by Huckabee was a available index to evaluate metabolic acidosis during the extracorporeal circulation. 5) With aid of surface cooling, the acid-base balance during perfusion was kept to lesser extent than that of core cooling only. 6) This study indicated that the low priming perfusion in conjunction with surface cooling hypothermia was a reliable technique for the open heart operation and may be applied in more prolonged perfusion.

Acid-Base Equilibrium↗
PubMed1978

Myocardial protection during aortic valve replacement. Physiological and metabolic effects of selective coronary perfusion on the fibrillating heart.

The physiological effects and certain aspects of cardiac metabolism were studied in 14 patients undergoing primary aortic valve replacement. The operations were performed under moderate hypothermia (30 degrees +/- 2 degrees C) and blood for coronary perfusion was taken from a sidebranch of the arterial line. The majority of the hearts went spontaneously into ventricular fibrillation at some stage of the operation. In spite of the high resistance measured in the coronary perfusion cannulae, an intraluminar coronary blood flow of 380 ml/min was recorded. The myocardial oxygen uptake decreased to 6.0 ml/min at 29 degrees C compared with 20.0 ml/min at 36 degrees C. The elevated coronary sinus lactate throughout the period of coronary perfusion and the increasing level of ASAT-enzyme indicated that this technique could not fully protect the myocardium from ischaemic changes. One patient died of myocardial infarction and two others needed vasopressor support postoperatively, in spite of documented effective coronary perfusion throughout the procedure. Cannulation of the coronary sinus is a valuable adjunct for the study of cardiac metabolism during ECC and it was accomplished without complications.

Adult↗
PubMed1979

[Clinical application of a supplement to the extracorporal circulation to produce a pulsatile flow (author's transl)].

Two groups of patients with atherosclerotic coronary artery disease, who underwent aortocoronary bypass operation, were perfused with nonpulsatile flow during extracorporeal circulation (ECC) using membrane oxygenators. One group (MO) was used as a control, while for the other group (PAD) a Pulsatile Assist Device in the arterial line was employed. This apparatus consists of a balloon of 80 ml placed inside a rigid housing. The balloon is compressed by pressurized air or expanded by vacuum supplied by a driving console. The apparatus produced pulse amplitudes between 30 and 50 mm of mercury. Other than a very short-lasting fall in mean arterial pressure, thus showing diminished peripheral resistance, no perceptable advantages were found. Base excess and pH-changes showed no differences, also the given amount of sodium bicarbonate in both groups was the same. On the other hand significantly higher hemolyses took place, increasing with the duration of pulsation. The application of the apparatus as an arterial counterpulsator was possible with limitation in only 5 of 15 patients. In all other patients after a short time massive blood foaming developed in the PAD and the attempts had to be stopped because of the risk of gas embolism. In our opinion this apparatus is an unnecessary supplement to the ECC and as an arterial counterpulsator it seems too dangerous.

Adult↗