Clinical evaluation of heparin-coated circuits for routine coronary artery bypass grafting surgery: a prospective randomized study.

The aim of this study was to demonstrate the clinical and biological benefits of heparin-coated circuits in routine coronary artery bypass grafting (CABG). A prospective, randomized study was conducted in 80 patients undergoing routine CABG. Patients were randomized to either noncoated circuits (Group 1) or heparin-coated circuits (Group 2). A complete clinical evaluation was performed preoperatively at Days 0, 1, 2, and 3 and at discharge day and combined with extensive laboratory tests for hemostasis and inflammatory response. This study did not prove any major statistically significant clinical benefit of heparin-coated circuits in low risk patients. Postoperative bleeding, significantly less in the heparin-coated group, did not decrease significantly the number of transfused patients. Biological values were not changed significantly except for factor II and monocytes, which were higher in Group 2. Heparin-coated circuits offer minimal clinical and biological benefits for routine CABG surgery. However, they may prove beneficial for complex procedures or at-risk patients.

Centrifugal pumps and heparin-coated circuits in surgical treatment of giant cerebral aneurysms.

Giant cerebral aneurysms may be untreatable by conventional neurosurgical techniques. Early attempts to use circulatory assistance and deep hypothermia were abandoned due to hemorrhagic complications. More recently, interest in circulatory support for complex neurosurgical procedures has been renewed. A consecutive series of 8 patients were operated on for giant cerebral aneurysms with the combined use of deep hypothermia. The protocol included careful preoperative cardiovascular assessment, perfect intraoperative synergy between neurosurgical and cardiac teams, minimally invasive peripheral vascular access including two femoral vein (21 F) and single arterial (17 F) femoral cannulation, use of total Carmeda coating on BioMedicus pumps in closed circuits, and reduced heparinization without Protamine reversal. All cerebral aneurysms were successfully treated through deep hypothermia (15-18 degrees C) as assessed by intraoperative fluoroscopic controls and Doppler vascular assessment. Mean circulatory support time was 174.2 +/- 29.6 min. Circulatory arrest period was 20 +/- 12 min. All patients survived and were extubated within 48 h. No major deficit was observed clinically or on postoperative CT scan. No hemorrhagic complications occurred (mean transfusions was 2.2 blood units). This work supports an extensive use of heparin-coated surfaces for complex circulatory assist techniques, either for cardiac or extra cardiac complex procedures.

Circulatory assist techniques after cardiomyoplasty. Determinants for clinical outcome and later consequences.

Cardiomyoplasty, in spite of recent improvements, remains a high risk operation. The early postoperative period is sometimes very critical, even for patients selected from preoperative New York Heart Association functional class IV. During the surgical period, poor hemodynamics may be responsible for early death, as well as influence latissimus dorsi muscle long-term viability. Circulatory assist, including pharmacologic support with enoximone, intraaortic balloon counterpulsation (IABP), and ventricular assist devices (VAD), may be needed. From February, 1993 to September, 1994, 14 clinical dynamic cardiomyoplasty procedures were performed using the Medtronic (Minneapolis, MN) system at Hôpital La Timone, Marseille, France. Eight patients suffered from early and severe postoperative heart failure. Enoximone was used in three patients and IABP in five patients. Two days after cardiomyoplasty, one of the IABP patients required an implantable left VAD (Thermocardio Systems, Woburn, MA) as a bridge to cardiac transplantation. Overall hospital mortality was 7%. The authors studied the preoperative clinical data and surgical techniques to find specific risk factors that could have influenced postoperative events. Another aim of this study was to evaluate long-term benefits in these particular patients. Results showed that cardiomyoplasty patients may require complex means to overcome postoperative hemodynamic failure, but without necessarily poor long-term results. This should be an important step in improving future patient selection.

Clinical situations and results of cardiopulmonary support by peripheral access for resuscitation and recovery.

Use of cardiopulmonary support (CPS) by peripheral access with a membrane oxygenator has made considerable progress as a result of the development of centrifugal pumps, percutaneous cannulation, and preheparinized circuits. We have used CPS for resuscitation in 3 cases, for recovery after cardiotomy in 6 cases (myocardial insufficiency, 4; pulmonary arterial hypertension, 1; respiratory insufficiency, 1), and after heart transplantation in 1 case. Of these 10 patients, 3 died during CPS, 5 were successfully weaned, and 2 underwent heart transplantation. Use of CPS is expanding for emergency cardiac assistance. Installation is simple and rapid. It allows recovery of organs pending more invasive and costly techniques.

The early period of experimental Mendelson's syndrome in dogs with PaCO2 and pH in a normal range.

In 9 dogs the first 240 min of experimental Mendelson's syndrome were studied. To minimise hemodynamic alterations, the PaCO2 and pH were kept within the normal range. An increase in pulmonary artery pressure, Qs/Qt and a decrease in PaO2 were demonstrated. Diminution of heart rate and cardiac index were associated with the decrease of systemic oxygen transport. The first 30 min appeared as a para-sympathetic syndrome, the remainder of the experiment as a hypovolemic syndrome. Severe hypoxia was observed during the two periods.

[Hemodynamic effects of 2 different doses of midazolam in combination with fentanyl for induction of anesthesia in surgery of the abdominal aorta]. / Effets hémodynamiques de deux posologies de midazolam associées au fentanyl lors de l'induction pour chirurgie de l'aorte abdominale.

The haemodynamic effects of anaesthetic induction with midazolam, fentanyl and pancuronium bromide were studied in two groups of patients undergoing abdominal aortic surgery: group A (10 patients receiving 0.2 mg X kg-1 midazolam) and group B (9 patients receiving 0.3 mg X kg-1 midazolam). Haemodynamic parameters were measured before induction after fluid loading and 15 min after induction. Heart rate, mean right atrial pressure, systemic and pulmonary vascular resistances, mean pulmonary wedge pressure and right ventricular stroke work index remained steady. On the other hand, mean arterial and pulmonary arterial pressures, systolic, cardiac and left ventricular stroke work indices fell significantly in both groups. However there was no statistically significant difference between the two groups.

[Comparison of the hemodynamic effects of midazolam-fentanyl and thiopental-fentanyl combinations in the induction of general anesthesia]. / Comparaison du retentissement hémodynamique d'une association midazolam-fentanyl et thiopental-fentanyl á l'induction d'une anesthésie générale.

The hemodynamic changes during anesthetic induction for elective abdominal aortic surgery were studied in two groups of patients. Group M (9 patients) received midazolam 0.3 mg . kg-1 and fentanyl 6 micrograms . kg-1. Group T (10 patients) received thiopentone 6 mg . kg-1 and fentanyl 5 micrograms . kg-1. The radial and pulmonary arteries were catheterized under local anesthesia. An intravenous infusion was administered in order to normalize pulmonary wedge pressure. Systemic and pulmonary arterial pressures, pulmonary wedge pressure, cardiac output and heart rate were measured after the infusion and 5 min after intubation. Mean arterial pressure showed a statistically significant reduction in both groups. Cardiac index remained unchanged in group M, but was significantly diminished in group T. There was no significant reduction in the systemic vascular resistance index for group M, but group T showed a statistically significant increase. This study confirmed the good hemodynamic tolerance of the midazolam induction technique, even with a high dose of 0.3 mg . kg-1.

The infusion of catecholamines in dogs under general anaesthesia with fentanyl. The effects on intrapulmonary shunt.

The pulmonary venous admixture, PaO2, and pulmonary and systemic haemodynamics were studied in six mongrel dogs during infusion of dobutamine (infusion rate 7.5 micrograms . kg-1 . min-1), dopamine (7.5 micrograms . kg-1 . min-1) and isoproterenol (0.1 microgram . kg-1 . min-1). Anaesthesia was performed by a single injection of Fentanyl (0.35 mg/kg). The carbon dioxide tension and body temperature were strictly maintained within limits. Only isoproterenol produced a significant change in pulmonary arterial pressure from an average of 1.2 +/- 0.4 kPa to 1.6 +/- 0.2 kPa (P less 0.05). There was no significant change in systemic haemodynamics with any of the three drugs. The use of catecholamines in dogs with healthy lungs does not induce any development in pulmonary venous admixture when haemodynamics are unchanged. Changes in these variables are dependent upon changes in pulmonary blood flow rather than being direct effects of the catecholamine.

[Cardiovascular effects of a single injection of fentanyl in dogs under acute experimental conditions]. / Effets cardiovasculaires d'une injection unique de fentanyl chez le chien en expérimentation aigüe.

Experimental studies carried out in unselected dogs often face the problem of instabilit of various parameters both in terms of haemodynamics as well as acid-base balance. It is possible, with the injection of a single dose of Fentanyl of 0.35 mg.kg-1 given over a period of ten minutes to obtain, from the 30th minute after the injection, satisfactory cardiovascular stability (confirmed during 120 minutes in 9 dogs and 360 minutes in 2 of them). This haemodynamic state at T + 30 is obtained with a fall in mean blood pressure of -40 per cent, and an increase in peripheral resistance of +38 per cent and stroke volume of +11 per cent. This stability, obtained at the price of a stable normacapnia, correction of any possible metabolic acidosis and maintenance of body temperature, makes it possible to study the cardiovascular effects of certain types of treatment or of induced pathology.

[Chronic intracerebral electric stimulation for analgesia in man]. / La stimulation électrique intracérébrale chronique à visée antalgique chez l'homme.

This report concerns the current status of the results of intraencephalic implantations carried out up to the present time in man with the aim of relieving certain forms of chronic pain. It places little emphasis upon the neuro-physiological basis of these implantations, which have been studied at length during previous reports. After presenting the overall results of operations carried out in the world up until September 1967, a critical study is undertaken: 1--In relation to the targets (Postero-Lateral Ventral Nucleus, posterior arm of the internal capsule, para-ventricular thalamic grey matter). 2--In relation to etiologies, both analytically (syndrome) by syndrome as well as in terms of synthesis (excess of pain perception-deafferentation). 3--In terms of various factors, such as: --technical requirements; --side ffects; --duration of "post effect" (residual analgesia after stimulation); --parallel action of drugs. Conclusions are drawn concerning future perspectives of this technique.