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Biomedical subjects

P Léger

Publications and source records attributed to P Léger.

At least 19 recordsLinked to original sources
PubMed2003

[Identification of risk factors for allogenic transfusion in cardiac surgery from an observational study].

OBJECTIVE: To determine perioperative variables for predicting allogenic transfusion in adult cardiac surgery. STUDY DESIGN: Prospective study. PATIENTS: We included 335 consecutive patients undergoing cardiac surgery between February and April 2001. METHODS: Perioperative variables were prospectively collected in a database. For each patient who received transfusion, hemoglobin threshold for transfusion and total number of units of red cell concentrates were collected. Univariate and multivariate analysis were performed. RESULTS: The two strategies for blood conservation which were predominantly used were aprotinin therapy (78%) and blood salvage from the extracorporeal circuit (68%). During perioperative period, 42% of patients [95% CI: 37-47%] received allogenic transfusion. The haemoglobin threshold for transfusion was 7.4 +/- 1.1 and 8.0 +/- 0.7 g x dl(-1) in operating room and in intensive care unit, respectively. On average, 3.4 +/- 2.7 units of red cell concentrates were transfused perioperatively per patient. Using multivariate analysis, perioperative allogenic transfusion was significantly associated with the following variables: preoperative haemoglobin level < 12 g x dl(-1) (odds ratio 8.9; p = 0.001), emergency procedure (odds = 3.7, p = 0.01), reoperation (odds ratio = 3.3; p = 0.002), chronic obstructive pulmonary disease (odds ratio = 2.5; p = 0.03) and complex surgery (odds ratio = 2.4; p = 0.01). The age, the gender, and body mass index were only independent risk factors by univariate analysis. CONCLUSION: In despite of techniques to limit requirement of allogenic transfusion, a large proportion of cardiac surgical patients remains transfused. Independent risk factors of perioperative transfusion are haemoglobin level < 12 g x dl(-1), emergency procedure, reoperation, chronic obstructive pulmonary disease and complex surgery.

Adult↗
PubMed2003

Target-controlled infusion of propofol and remifentanil in cardiac anaesthesia: influence of age on predicted effect-site concentrations.

BACKGROUND: Propofol-anaesthesia administrated via target-controlled infusion (TCI) has been proposed for cardiac surgery. Age-related changes in pharmacology explain why propofol dose requirement is reduced in elderly patients. However, the Marsh pharmacokinetic model incorporated in the Diprifusor propofol device does not take age into account as a covariable. In the absence of depth of anaesthesia monitoring, this limitation could cause adverse cardiovascular effects resulting from propofol overdose in older patients. We assessed the influence of age on effect-site propofol concentrations predicted by the Diprifusor and titrated to the bispectral index score (BIS) during cardiac anaesthesia. METHODS: Forty-five patients received propofol by Diprifusor and remifentanil by software including Minto model. Propofol and remifentanil effect-site concentrations were adapted to BIS (40-60) and haemodynamic profile, respectively. The influence of age on effect-site concentrations was assessed by dividing patients into two groups: young (<65 yr) and elderly (> or =65 yr). RESULTS: For a similar depth of anaesthesia, effect-site propofol concentrations were significantly lower in elderly patients at the different stages of cardiac surgery. The mean dose of propofol required to perform tracheal intubation was significantly lower in elderly patients. However, the overall doses of propofol were comparable in both groups. Neither effect-site remifentanil concentrations nor overall doses of remifentanil were significantly different between the two groups. CONCLUSIONS: In cardiac anaesthesia, target concentrations of propofol must be reduced in elderly patients. Although this probably contributes to improving intraoperative haemodynamic stability, the absence of decrease in overall dose requirement of propofol suggests that this adjustment is relatively moderate.

Adolescent↗
PubMed2002

[Oral anticoagulant treatment: practical aspects and significance of anticoagulant clinics].

Vitamin K antagonists (VKA) decrease the synthesis of the active forms of four coagulation factors (factors II, VII, IX, X) and three inhibitors (proteins C, S, Z). There are VKA having a short half life (Sintrom, Pindione) and VKA having a long half life (Apegmone, Previscan, Coumadine). The treatment is monitored by the INR which in the majority of the indications must range between two and three. The first INR is usually performed 36 to 72 h after starting the treatment. There are a number of drug interactions. The rate of major bleedings range from 1.1 to 4.9 for 100 patient-year according to the published studies. Since around 600,000 patients are treated by VKA in our country, the absolute number of serious bleeding is high (> or = 17,000 per year). Anticoagulant clinics are structures aimed to instruct the patient and to advise the general practitioner to monitor the treatment, using computer assisted methods. It has been reported that these structures reduce the incidence of bleeding and of thrombotic events by 3 to 4 times.

Acenocoumarol↗
PubMed2002

[Validation of a French translation of the Edinburgh claudication questionnaire among general practitioners' patients].

OBJECTIVES: Intermittent claudication is one of the clinical symptoms of peripheral arterial disease (PAD). The presence of PAD is a high risk marker of cardiac events and stroke. The PAD screening can be enhanced by the use of questionnaires. The Edinburgh Questionnaire presents in its English version better diagnostic performances compared to the Rose (WHO) Questionnaire. The aim of this study is to precise the performances of the French version of the Edinburgh Questionnaire among a population consulting general practitioners. METHODS: Four centers instructed 10 general practitioners each to the measurement of ankle pressure with a Doppler stethoscope. The physicians administrated the Questionnaire to 10 consecutive consultants in a same day, and measured the pressure on posterior tibial, dorsalis pedis and humeral arteries. With a second questionnaire they collected data concerning age, weight, height, and the presence of major risk factors. The same protocol was repeated a second day on new patients. The diagnosis of PAD was based on an ankle-arm index lower than 0.85 for at least on limb. RESULTS: The population studied consisted of 727 subjects (351 females and 376 males). The mean age was at 58.3 +/- 16.1 years (ranging from 18 to 83.3 years). The sensitivity of the Questionnaire is at 47% (95% CI: 32.3-61.7%), the specificity at 98.8% (95% CI: 97.5-99.4%), the positive and negative predictive values are respectively at 73.3% (95% CI: 54.1-87.7%) and 94.8% (95% CI: 94.7-97.6%). Among this population of general practitioners consultants, the prevalence of a low ankle-arm index under 0.85 is at 6.7%. DISCUSSION: The French version of the Edinburgh Questionnaire maintains the very good specificity of the English version. The lower sensitivity could be explained by the choice of the gold standard, namely the ankle-arm index which includes asymptomatic patients with authentic PAD. The use of this Questionnaire can be recommended for the screening of this disease as well as in epidemiological studies.

Adolescent↗
PubMed2001

Surgical exposure of superior sulcus lung tumors with vascular involvement.

Choice of exposure route for surgical excision of superior sulcus lung tumors depends on involvement at the thoracic inlet. From December 1985 to September 1999, we performed surgical treatment of superior sulcus tumors in 42 patients, including 22 with vascular involvement. Various exposure techniques were used, including a novel technique combining transverse supraclavicular cervicotomy and posterolateral thoracotomy in 11 cases, anterior transclavicular cervicothoracotomy in 7 cases, isolated posterolateral thoracotomy in 3 cases, and cervicosternotomy in 1 case. Vascular procedures consisted of subadventitial dissection of the subclavian artery in 5 patients, arterial resection-anastomosis in 7, and prosthetic bypass in 10. Postoperative mortality was 11.9% in the overall series of 42 patients (n = 5) and 9% (n = 2) in the subgroup of patients with vascular involvement. During follow-up, 13 patients died of tumor recurrence and 1 patient died of respiratory insufficiency. Actuarial 5-year survival was 22.7 +/- 17.5% overall and 18 +/- 17.9% in the subgroup of patients with vascular involvement. This study indicates that the combined exposure route with transverse supraclavicular cervicotomy and posterolateral thoracotomy was useful for treatment of superior sulcus lung tumors requiring lobectomy and pneumonectomy.

Actuarial Analysis↗
PubMed2001

[Buerger's disease or thromboangiitis obliterans].

The Buerger's disease or thromboangiitis obliterants (TAO) is a non atheromatous inflammatory disease which alters medium and small-sized arteries and veins. It can be found world-wide, but it is more frequent in Eastern Europe, Middle East, Asia and Southeast Asia. Young men and smokers are the most affected. The incidence of this disease is increasing among women. The cause of this disease is unknown yet. The most striking fact is the relationship between TAO and tobacco. The diagnostic is most often late in front of a digital leg ischemia. Complementary exams help to its diagnostic and management but none of them are specific out of the pathology. The affection is evolving towards distal gangrene with amputation in 5 to 10% of cases. Prostacyclin demonstrated its efficiency. Revascularization surgery is difficult but sometimes possible. Sympathectomy, medular stimulation must be suggested. The patient survival is not at stake and the prognosis is above all functional. The most important element in the treatment is stop smoking definitively.

Humans↗
PubMed2001

Expanded polytetrafluoroethylene membranes to wrap surfaces of circulatory support devices in patients undergoing bridge to heart transplantation.

OBJECTIVE: Because of a lack of donor hearts, an increasing number of patients with heart failure must now undergo bridge to cardiac transplantation with a mechanical circulatory support device. Moreover, support periods have become longer. As a result, pericardial adhesions may develop while the support device is implanted, increasing the risk of injury at resternotomy and bleeding after transplantation. Use of expanded polytetrafluoroethylene (ePTFE) pericardial substitutes (membranes) may prevent such adhesions. PATIENTS AND METHODS: From January 1997 to December 1999, ePTFE membranes were used in 23 patients to wrap portions of an implanted left ventricular assist device (LVAD) or total artificial heart (TAH). Any complications during mechanical support or at cardiac transplantation were recorded. Six ePTFE membranes removed at transplantation were studied histologically. RESULTS AND CONCLUSIONS: At resternotomy for transplantation, the plane of dissection between tissues, ePTFE membranes, and surfaces of the mechanical support device were easily discerned. No adhesions were observed between tissues and membranes. There were no injuries during resternotomy and no patient had to undergo reoperation because of bleeding. One patient given a TAH had an infection during circulatory support that was controlled by antibiotic therapy. In another patient, clots developed between the device and an ePTFE membrane; these were removed successfully. Histologic studies of removed ePTFE membranes showed no infiltration of the membranes interstices by collagen or cellular components. Use of ePTFE membranes in patients undergoing bridge to transplantation with either an LVAD or a TAH limited adhesions between tissues and device surfaces without increasing the risk of infection.

Adolescent↗
PubMed2001

Anti-thrombotic and haemorrhagic effects of active site-inhibited factor VIIa in rats.

Active site-inhibited factor VIIa (FFR-rFVIIa) competes with factor VIIa (FVIIa) for binding to tissue factor (TF) and exerts an anti-thrombotic effect. We report an evaluation of the anti-thrombotic properties of FFR-rFVIIa in a model of thrombosis involving two thrombogenic surfaces. Uncoated glass capillaries or glass capillaries coated with TF were incorporated into an arterioarterial shunt in the rat and the occlusion time (OT) of the shunt was determined. An anti-thrombotic activity of FFR-rFVIIa was shown only on the TF-coated surface: the OT of the shunt was significantly prolonged, from 167 +/- 34 s in control animals to 312 +/- 42 s after i.v. bolus administration of 4 mg/kg FFR-rFVIIa. This OT was similar to those observed with the uncoated shunts in untreated animals (353 +/- 84 s). In vitro preincubation of the TF-coated shunt with FFR-rFVIIa significantly prolonged the OT to 245 +/- 45 s in the absence of detectable amounts of FFR-rFVIIa in the plasma. rFFR-rFVIIa weakly prolonged the tail template bleeding time by a factor of 1.5. This effect was more pronounced in animals pretreated with heparin. The anti-thrombotic and prohaemorrhagic effects of FFR-rFVIIa were totally reversed by administration of an equidose of rFVIIa. These results provide new information on the pharmacological properties of FFR-rFVIIa that will be useful for its clinical development.

Animals↗
PubMed2001

A monitor unit "odometer" for measuring linac workload.

The annual linac workload is often required by regulatory agencies to assess compliance with license conditions. Summation of the monitor units produced by the machine is generally used for this purpose. Various methods of estimating this value have inherent inaccuracies. We have built an integrating Monitor Unit "odometer" that is able to automatically accumulate all MUs delivered by the linac and segregate the total by mode (photon or electron) and energy. The device has been used to record clinical linac MU workloads for 10 months, and was installed in a new dual-energy linac during the acceptance and commissioning process.

Electrons↗
PubMed2000

[End-stage heart failure: role of various circulation assistance techniques].

There are currently 4 main types of cardiac assist devices: centrifugal pumps, paracorporeal pneumatic assist devices, implantable ventricular assist devices, total artificial heart. Although the efficacy of centrifugal pumps remains limited, that of the other 3 types of assist devices has now been clearly demonstrated. The choice between these various devices depends on the severity of heart failure at the time of implantation, the univentricular or biventricular disease, the potential for recovery, the patient's morphology and obviously the device or devices available to the team concerned. The results essentially depend on early implantation.

Chronic Disease↗
PubMed1999

[Chronic obliterative arterial disease of the lower limbs in the coronary patient: prevalence and prognostic incidence. The Monica Toulouse register].

PURPOSE: This study was aimed at evaluating the prevalence of peripheral arterial disease of the lower extremities and its prognostic value in a population of patients from the Haute-Garonne department, who were hospitalized for acute coronary artery disease. METHODS: Between 1985 and 1991, four thousands three hundred and sixty-eight patients (3,680 males and 688 females) presenting with acute coronary artery disease were included in the study. RESULTS: The prevalence of peripheral arterial disease of the lower extremities was 13.4%, increasing with age and being higher in male patients. In regard to patients hospitalized for acute myocardial infarction (n = 2,417), independent relationships were observed between the 28-day mortality and the following: patient's age (odds ratio: 1.02; 95% confidence interval: 1.01-1.04; P < 0.0005), female gender (odds ratio: 1.32; 95% confidence interval: 1.17-1.54; P < 0.002), inclusion in the study (odds ratio 0.95; 95% confidence interval: 0.90-0.99; P < 0.02), previous coronary artery disease (odds ratio: 2.88; 95% confidence interval: 2.32-3.48; P < 0.0001), and peripheral arterial disease (odds ratio: 1.61; 95% confidence interval: 1.26-2.06; P < 0.0001). CONCLUSION: The prevalence of peripheral arterial disease of the lower extremities is high in patients with acute coronary artery disease in both genders, whatever the age. This disease is therefore an independent marker of mortality for acute myocardial infarction. Easy diagnosis of peripheral arterial disease of the lower limbs by measurement of the ankle pressure index allows identification of patients prone to death from acute myocardial infarction.

Adult↗
PubMed1999

Pericardial cardiac troponin I release after coronary artery bypass grafting.

UNLABELLED: Pericardial fluid can reflect the composition of cardiac interstitium in myocardial ischemia. This study investigated the hypothesis that pericardial cardiac troponin I (CTnI) measurements could be a more accurate marker of perioperative myocardial infarction (MI) than serum CTnI after coronary artery bypass grafting (CABG). Postoperative arterial and pericardial blood samples were taken in 102 subjects undergoing elective CABG allocated to one of three groups according to the 12-lead electrocardiogram (ECG) abnormalities observed during the first postoperative 24 h: Group 1 = normal ECG; Group 2 = nonspecific ECG abnormalities; and Group 3 = perioperative Q-wave MI. Peak pericardial CTnI concentrations were much higher than peak serum concentrations in all subjects and significantly greater in Group 3 than in Groups 1 and 2 (1,318 +/- 1,810 ng/mL vs 367 +/- 339 ng/mL and 558 +/- 608 ng/mL, respectively; P < 0.01). However, no significant difference between groups occurred at any time for pericardial/serum CTnI ratios, indicating that time courses of CTnI were not different in pericardial fluid and serum. A significant correlation was found between serum and pericardial CTnI concentrations (R = 0.70, P < 0.001). Pericardial CTnI was not more accurate than serum CTnI in predicting Q-wave MI as shown by the low value of the area under the receiver-operator characteristic curve (= 0.71). Peak and early pericardial CTnI were also not accurate in predicting an increase of serum CTnI greater than a cutoff value of 19 ng/mL. Thus, pericardial CTnI measurements were less useful than serum CTnI measurements in the diagnosis of perioperative MI after CABG. IMPLICATIONS: Although cardiac troponin I concentrations were much higher in pericardial fluid than in serum and significantly increased in subjects who experienced perioperative Q-wave myocardial infarction, pericardial cardiac troponin I measurements were of less value than serum cardiac troponin I measurements for the diagnosis of perioperative myocardial infarction after coronary artery bypass grafting and cannot be recommended in routine clinical practice.

Aged↗
PubMed1998

Left centrifugal pump cardiac assist with transseptal percutaneous left atrial cannula.

Left cardiac support postcardiotomy requires a second operation for removal of the atrial cannula following weaning from assistance. To avoid the risk of this procedure, we used a transseptal cannula prototype. The cannula was introduced percutaneously through the femoral vein and advanced into the left atrium guided by the finger of the surgeon. Optimal positioning of the tip of the cannula was verified by perioperative transesophageal echocardiography. A long arterial cannula was positioned in the descending aorta via the femoral artery and a Carmeda circuit with a centrifugal pump was connected to both cannulas. This procedure was used in 3 patients with low cardiac output who underwent emergency surgery, a 63-year-old patient referred for aortic and mitral valve replacement, a 54-year-old man for aortic valve replacement, and a 64-year-old patient in the acute phase of myocardial infarction after myocardial revascularization. The assistance was used systematically at the end of the operation. The assist flow was 1.2-2.6 L/min. The patients were all weaned from support between 18 h and 8 days later. No complications related to the device occurred. Both cannulas were removed surgically from the femoral vessels without reopening the chest. This new procedure is of interest for 2 reasons: the systematic implantation allows for early assistance, and the use of a percutaneous approach avoids the risk of reopening the chest. More cases are needed to confirm this initial good impression.

Aortic Valve Insufficiency↗
PubMed1998

Erythrocyte hyperaggregation and thrombogenic dysfibrinogenemia.

Erythrocyte aggregation was measured in 12 patients with congenital dysfibrinogenemia. The results showed hyperaggregation in four patients who had presented a thrombotic disorder, while aggregation was entirely normal in patients with asymptomatic dysfibrinogenemia. None of the four symptomatic patients had any other anomaly of hemostasis, in particular no coagulation inhibitor deficit or anti-phospholipid antibodies. The possible involvement of erythrocyte hyperaggregation in the thrombotic process is discussed.

Adult↗