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Biomedical subjects

O Bastien

Publications and source records attributed to O Bastien.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Intensive care in lung and heart-lung transplantation].

Intensive care after lung, and heart-lung transplantation may have simple post operative course specially after preventive procedures of reperfusion injury, nosocomial infections during mechanical ventilation and immunosuppression risks. Nevertheless a severe mediastinal shift may occurred after single lung transplantation in emphysema. Rapid changes in ventilation/perfusion ratio during lung infection or rejection specially in pulmonary hypertension are responsible of dramatic respiratory failure. Knowledge of multiorgan dysfunction and multidisciplinary experience encourage to future development.

Critical Care↗
PubMed1995

[Role of urapidil in the treatment of acute hypertension].

Urapidil is a vasodilator acting on peripheral vessels by alpha-1 adrenoceptor blockade, and on central nervous system by alphaadrenoceptor blockade on the tractus solitarius nuclei and stimulation of serotoninergic receptors. Its hepatic metabolism and central action explain the absence of rebound effect when treatment is stopped. Urapidil is an arterial and venous vasodilator in systemic and pulmonary circulation. Therefore urapidil decreases systemic and pulmonary arterial pressures and left and right ventricular preload. These effects are accompanied by moderate effects on heart rate, and increased cardiac output in patients with heart failure. Some adverse effects observed with other vasodilators are absent (increased intracranial pressure and intrapulmonary shunt, negative inotropic effect, tachycardia). IV urapidil is used to treat systemic arterial hypertension perioperatively and hypertensive emergencies. Moreover urapidil has been administered to treat pulmonary artery hypertension in chronic pulmonary disease. Its haemodynamic effects seem proportional to the basal activity of alpha-adrenoceptors. Therefore, wide individual variations in active doses are observed from 12.5 to 50 mg as i.v. bolus in adults. Thereafter i.v. continuous administration or oral treatment may be necessary, depending on the cause of hypertension.

Acute Disease↗
PubMed1994

Clinical use of ganciclovir during renal failure and continuous hemodialysis.

OBJECTIVE: Data is scarce concerning ganciclovir, used in CMV-related diseases in transplant patient with renal failure, especially when dialysis is necessary. DESIGN: Prospective trial. SETTING: Intensive care unit in a university hospital, and pharmacy laboratory. PATIENTS: pharmacokinetics were obtained in 3 patients undergoing continuous veno-venous hemodialysis (CVVHD) (PAN 69). INTERVENTIONS: HPLC measurements of plasmatic and ultrafiltrated ganciclovir were determined at 17 times intervals after a 5 mg/kg every 48 h dosage. RESULTS: Peak and trough concentrations were respectively 16.1 +/- 2.4 and 5.5 +/- 0.5 mg/l, sieving coefficient 0.75-0.95, and volume of distribution at steady state 0.64 +/- 0.09 l/kg, half life (beta phase) 18.6 +/- 1.8 h. No direct toxicity, or CMV-related death occurred. CONCLUSION: Plasma concentrations were higher than the ID 90. A dosage of 5 mg/kg/48 h of ganciclovir could be used during CVVHD, and ideally adjusted to monitoring of plasma drug levels.

Chromatography, High Pressure Liquid↗
PubMed1994

[Antibiotic prophylaxis in heart surgery].

Cardiac surgery enters mainly into the class I of Altemeier ("clean surgery"). However, many factors may explain an intraoperative contamination: surgery of long duration, extra-corporeal circulation, aspiration of blood and air, immunodepression...). In fact, the infectious risk decreases from about 25% with placebo to 5% with prophylactic antibiotics. The staphylococcal infections are the most frequent (mediastinitis, endocarditis, parietal infections...). Cephalosporins, particularly of second-generation type (cefamandole, cefuroxime), perform better than antistaphylococcal penicillins. The combination with an amino-side may be used when Gram negative bacilli infection prevalence is high. Vancomycin is efficient but hypotension and renal impairment have been reported. Therefore, vancomycin is used in patients allergic to cephalosporins, when a high prevalence of methicillin-resistant Staphylococcus or enterococci infections is reported, or when the patient has recently received broad-spectrum antimicrobial therapy. The antibiotic doses must take into account the haemodilution due to extracorporeal circulation and the necessity to obtain sufficient serum concentrations throughout surgery. A prophylaxis of more than 48 hours is not associated with an improved outcome. In cardiac transplantation a prophylaxis is essential, but is still questioned during the insertion of pace-markers. In any case, the antibiotic prophylaxis must take into account the bacterial prevalence of each institution.

Aminoglycosides↗
PubMed1994

Disseminated Scedosporium prolificans (S. inflatum) infection after single-lung transplantation.

This report concerns the first case of disseminated infection with Scedosporium prolificans (S. inflatum) that occurred in a patient who had received an organ transplant and was verified at autopsy. The patient underwent single (right)-lung transplantation and subsequently died on the 33rd postoperative day in a context of septic shock. S. prolificans was isolated from various specimens, including two cultured blood samples. The organism was associated with Candida albicans in some of these specimens. Autopsy revealed the presence of numerous nodular abscesses in the lungs, myocardium, kidneys, spleen, and gall bladder. These abscesses contained mycelial filaments and numerous oval conidia suggestive of Scedosporium species but no yeasts. MIC studies demonstrated the resistance of the S. prolificans isolate to amphotericin B, fluctyosine, miconazole, ketoconazole, and itraconazole, whereas the isolate of C. albicans was susceptible to amphotericin B, flucytosine, miconazole, and ketoconazole. From the data from our case and six published reports of cases of disseminated S. prolificans infection, it can be concluded that this filamentous fungus is a new agent responsible for the most serious mycoses in both neutropenic patients and patients who have undergone organ transplantation.

Candidiasis↗
PubMed1994

Enoximone and acute left ventricular failure during weaning from mechanical ventilation after cardiac surgery.

OBJECTIVE: To evaluate enoximone, a phosphodiesterase III inhibitor, in the treatment of left ventricular failure during the weaning of patients from mechanical ventilation after heart surgery. DESIGN: Open label, prospective, weaning trial. SETTING: Cardiothoracic surgical intensive care unit (ICU) in a university hospital. PATIENTS: Nine patients were studied after one or more unsuccessful attempts at weaning from mechanical ventilation due to left ventricular dysfunction. INTERVENTION: For each patient, two respiratory weaning attempts were studied: the first one as a control and the second one with enoximone infused at a rate of 30 micrograms/kg/min for 30 mins, then at a rate of 10 micrograms/kg/min. MEASUREMENTS AND MAIN RESULTS: Hemodynamic measurements were performed at the following interval times: baseline during mechanical ventilation; during spontaneous ventilation with a T-piece for a minimum of 10 mins; during mechanical ventilation after the enoximone infusion for 30 mins; during spontaneous ventilation for a minimum of 10 mins with an enoximone infusion running. During spontaneous ventilation, enoximone increased cardiac index by 34% but mean artery, right atrial, and pulmonary artery occlusion pressures did not change. Despite an increase in venous admixture due to augmented cardiac index and inhibition of hypoxic vasoconstriction, no oxygen debt occurred because oxygen delivery increased. Seven of nine patients were weaned successfully from mechanical ventilation. CONCLUSION: Because of its positive inotropic and vasodilatory properties, enoximone is helpful for respiratory weaning of patients with left ventricular failure after cardiac surgery.

Aged↗
PubMed1993

Pharmacokinetics of ganciclovir in heart transplant patients undergoing continuous venovenous hemodialysis.

The pharmacokinetics of ganciclovir in patients with severe renal dysfunction is poorly defined. In this paper, we report the pharmacokinetics of ganciclovir in three anuric heart transplant patients under continuous venovenous hemodialysis (CVVHD). Ganciclovir was administered at a dose of 5 mg/kg every 48 h for at least 9 days. Samples from the arterial and venous blood lines and from ultrafiltrate were collected to calculate pharmacokinetic parameters, clearance of ultrafiltration, and sieving coefficient. Ganciclovir concentrations were determined by high-performance liquid chromatography. Pharmacokinetic parameters (mean +/- SD) were the following: t1/2 beta 18.9 +/- 2.2 h, Cl 0.42 +/- 0.08 ml/min/kg, Vdss 0.68 +/- 0.10 L/kg. At the steady state the clearance of ultrafiltration was 12.9 +/- 1.9 ml/min (or 130 L/week) and the sieving coefficient was 0.84 +/- 0.08 with an average fraction of 89.7 +/- 10.6% of the administered dose removed by CVVHD. These results show that CVVHD is highly effective in removing ganciclovir from plasma. Furthermore, CVVHD appears more effective than intermittent hemodialysis. These data should be taken into account to optimize dosage adjustment of ganciclovir in patients under CVVHD, and until guidelines are available, careful monitoring of drug concentrations is recommended.

Adult↗
PubMed1993

[Cytomegalovirus arteriolitis: gangrene of the feet and early coronary disease after heart transplantation].

Peripheral arteriolitis of the legs from the 4th postoperative day after cardiac transplantation caused ischemia of the feet and required bilateral transmetatarsal amputations on the 28th postoperative day. The causal condition was cytomegalovirus infection, confirmed by rising IgM antibody titres, the detection of a viraemia on the 33rd postoperative day, and, above all, the presence of cytomegalic inclusion bodies in many endothelial arteriolar cells of the amputated limbs. The patient died four months after transplantation and autopsy revealed major lesions in all the distal coronary vessels of the graft which occluded over 4/5ths of the coronary lumens. An aspergillus septicemia was the direct cause of death.

Coronary Disease↗
PubMed1993

[Fatal aspergillosis after cardiac transplantation. About 26 cases].

Complications due to infection by aspergillus and favorized by therapeutic immunodepression are a significant cause of mortality after cardiac transplantation, but are only rarely diagnosed before autopsy. A detailed description of the anatomical lesions and their localisation might help the interpretation of symptoms observed in vivo. In a series of 147 autopsies subsequent to cardiac transplantation, aspergillosis appeared as the cause of death in 26 cases. Three anatomoclinical presentations could be identified: early post-operative septic pyohaemia (14 cases), delayed septic pyohemia (7 cases) and forms with predominantly pulmonary involvement (5 cases). In the first category, cardiac lesions are the most evident with myocardial micro-abscesses and intracardiac masses of aspergillus presenting a variable risk of embolism. Pulmonary << target lésions >> (infarctus associated with a variable degree of aspergillus arterial thrombosis) were present in all cases. Visceral involvement completes the picture; the more frequent lesions being acute pancreatitis (9 cases), infarctogenic aspergillus emboli of the kidneys (11 cases), the spleen (9 cases) or the brain (6 cases). In 8 subjects, microscopical examination revealed other germs associated with aspergillus. The serious consequences of aspergillus infection after cardiac transplantation imply that every preventive precaution should be taken, especially in avoiding possible contamination of the air of the operating room by the installation of filters and the regular control of airways and air conditioning systems.

Abscess↗
PubMed1993

Immunization by bovine thrombin used with fibrin glue during cardiovascular operations. Development of thrombin and factor V inhibitors.

Brief case histories of three patients aged 58, 38, and 44 years are reported. All underwent cardiovascular operations. Subsequently hemostasis test abnormalities developed between the seventh and eighth postoperative days after exposure to bovine thrombin used with fibrin glue. These were characterized by an increased activated partial thromboplastin time (64 to 147 seconds), prothrombin time (19 to 24 seconds), bovine thrombin time (> 120 seconds) and a markedly reduced factor V level (< 10% in two patients and 16% in the third patient). A patient plasma dilution of 1 in 200 with a normal plasma pool was necessary to correct bovine thrombin time. No fast-acting or progressive inhibitor against factor V could be detected by coagulation tests, and fresh frozen plasma perfusion had no effect. Plasmapheresis was performed preventatively to avoid bleeding, and factor V levels stabilized at around 50% after two to four exchanges. Immunologic studies showed that the inhibitors were directed not only against bovine factors but also against human ones. Therefore factor V decrease could have been the result of rapid clearance from the circulation of complexes formed with a nonneutralizing inhibitor that is not detected by clotting tests. These antibodies were purified by standard methods and immunoaffinity. Fast immunization could be explained by a prior sensitization to bovine thrombin exposure during previous operations. It is suggested that bovine thrombin used with fibrin glue contains small amounts of factor V and may be responsible for these abnormalities. This is in agreement with previous literature reports. However, these described neutralizing factor V inhibitors, which were easily detected.

Adult↗
PubMed1992

Glucose and insulin supply before cardiopulmonary bypass in cardiac surgery: a double-blind study.

A double-blind study versus placebo was carried out to evaluate the effects of a 500-mL infusion of 30% glucose containing 300 units of ordinary insulin and 5 g of potassium chloride administered at a rate of 1.66 mL.kg-1.h-1 for 1 hour before cardiopulmonary bypass. The hemodynamic parameters measured before and after administration of the solution, after cardiopulmonary bypass, after administration of protamine, and 3 hours after leaving the operating room showed the beneficial effect of the glucose-insulin-potassium infusion on cardiac index (+23.6% after protamine infusion) and left (+16.3% 3 hours postoperatively) and right (+47.3% after cardiopulmonary bypass) ventricular workload index with a decrease in systemic vascular resistance. For patients with a cardiac index of less than 2.5 L.min-1.m-2 before administration of the glucose-insulin-potassium solution, the beneficial effect on the cardiac index was further increased 3 hours postoperatively (+33%). During the postoperative period, the requirements in inotropic drugs and disturbances of rhythm were not significantly different between the two groups, although they were twofold lower in patients receiving glucose-insulin-potassium. Laboratory tests showed that postoperative hypoglycemia was more common in the glucose-insulin-potassium group but had no detrimental effects; it no longer occurs since we began administering the glucose infusion at 15 g/h over 8 hours. The data reflect the beneficial effect associated with the action of glucose-insulin-potassium on myocardial protection during heart operations and were confirmed by the hemodynamic results. This argues in favor of the routine use of this technique, especially in patients with poor ventricular function.

Cardiac Surgical Procedures↗
PubMed1992

[Vascular effects of ketamine during anesthesia with diazepam and fentanyl].

Twenty-six adults undergoing elective cardiac surgery were anaesthetized with diazepam and fentanyl (induction with 200 micrograms.kg-1 and 30 micrograms.kg-1 respectively, maintenance with incremental doses). Normothermic constant perfusion output cardiopulmonary bypass was carried out with a membrane oxygenator, haemodilution with Ringer's lactate solution, and cardioplegia with St. Thomas's Hospital solution. The patients were randomly assigned to two groups. They were given either 2 mg.kg-1 of ketamine (group 1) or placebo (5 ml of normal saline) (group 2) via the venous line of the oxygenator. The non pulsatile flow was then kept at a steady rate of 2.41 x min-1.m-2, and no other infusion or treatment was started during the study period (ten minutes). The mean arterial pressure and blood reservoir level were measured every min during this period. The systemic vascular resistances did not change significantly in either group, but remained 27% lower in the ketamine group than in the placebo group (p less than 0.01). The blood reservoir level was 37% higher in the ketamine group (p less than 0.01), suggesting a decreased venous capacitance. It is therefore concluded that ketamine leads to venous constriction, and probably arterial dilation, during fentanyl-diazepam anaesthesia and normothermic cardiopulmonary bypass. The venous effects of ketamine could explain why it is usually well tolerated in hypovolaemic states.

Aged↗
PubMed1992

[Current role of intra-aortic diastolic balloon counterpulsation in heart surgery].

Intra-aortic balloon counterpulsation (IABP) is a relatively non-invasive method of circulating assistance, easy to use and which has benefitted from a number of technological improvements in recent years. This retrospective study over 4 years was undertaken to analyse the results of IABP and to determine its role in therapeutic arsenal against cardiac failure. Sixty five patients, 57 coronary and 8 valvular cases, with an average age of 61 +/- 10 years were included. The indications of IABP were: a bridge to transplantation (3 cases), complications of coronary angioplasty (4 cases), and low cardiac output after cardiopulmonary bypass (58 cases), where IABP was curative in 85% of cases and prophylactic in 15% of cases (patients with risk factors of low output state after CPB). Beforehand, 65% of patients had poor left ventricular function (LVEF < 40% and/or CI < 2.2 l/mn/m2). An Aries Medical M700 console was used. The percutaneous femoral approach was feasible in 87% of cases. The results were: improvement with discharge from intensive care unit in 60% of cases, transient improvement in 7% of cases, no improvement in 15% of cases and cardiac transplantation in 8% of cases. The outcome was worse when the preoperative LV function was poor and when high dose inotropic agents had to be used. Survival was 100% in those patients in whom IABP was a prophylactic measure. The average duration of IABP was 72 hours, survival being significantly lower in those in whom IABP was continued for over 3 days. The complications (12.7%) were thromboembolic.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗