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Biomedical subjects

F Sonaglia

Publications and source records attributed to F Sonaglia.

11 recordsLinked to original sources
PubMed2001

End points in studies on the prevention of deep vein thrombosis.

Clinically overt events are of obvious relevance for the outcome of patients. There is unanimous consensus of clinicians that these events should be prevented in clinical practice. In clinical trials on the prevention of deep vein thrombosis, symptomatic objectively confirmed venous thromboembolism is the most important outcome to be measured. However, because of the difficulties related to the measurement of clinically overt events, venography is the most commonly used method for end-point measurement in clinical trials on the prevention of venous thromboembolism. The limitations of venography leave a great need for the development of accurate noninvasive methods to be used as alternatives to venography. The end point must be tailored to the phase of the clinical trial. In phase I/II clinical trials, that are designed to evaluate the effectiveness of thromboprophylactic agents, it still is necessary to use the most accurate method for the diagnosis of deep vein thrombosis and to perform bilateral venography. When a new pharmacologic agent is compared with the "gold standard" agent, the use of symptomatic end points should be preferable.

Clinical Trials as Topic↗
PubMed2000

Prevention of venous thromboembolism.

Venous thromboembolism is the most common cause of preventable death among hospitalised patients. Systematic prophylaxis with antithrombotic agents in patients at risk for venous thromboembolism is the most effective approach to reduce morbidity and mortality. Despite this evidence, antithrombotic prophylaxis is still underused, due to the underestimation of incidence of venous thromboembolism and to the unjustified fear of bleeding complications. Both the characteristics of the individual patient and the clinical setting contribute to the definition of the risk for venous thromboembolism. Patient-related risk factors include clinical and molecular abnormalities. The grade of risk for venous thromboembolism is defined better by the clinical setting than by the patient characteristics. Prophylactic studies have been extensively carried out in surgical patients and, only more recently, in medical patients. Prophylactic methods include pharmacological agents, such as heparin, low molecular weight heparins, warfarin, and hirudin, as well as mechanical methods such as compression stockings and intermittent pneumatic compression.

Anticoagulants↗
PubMed2000

Low-molecular-weight heparins in the management of unstable angina.

Low-molecular-weight heparins (LMWHs) are derivatives of unfractionated heparin (UFH) and have a more favourable pharmacokinetic profile and a more predictable anticoagulant effect than UFH. These features allow the subcutaneous injection of weight-adjusted doses of LMWHs without monitoring of blood coagulation, and this results in cost savings. Clinical trials have shown that combined therapy with aspirin and LMWHs is significantly more effective than aspirin alone in reducing the risk of cardiac events in the acute treatment of patients affected by unstable angina. LMWHs have also been shown to be at least as safe and effective as UFH in reducing the incidence of death and myocardial infarction in patients with unstable angina. LMWHs appear to be at least as safe as UFH with regard to major bleeding risk. When given as extended therapy, LMWHs have been shown to be superior to placebo at 30 and 45 days, with an acceptable risk of bleeding. Additionally, LMWHs can be used as a 'bridge' to revascularization in patients for whom early invasive treatment is not readily available.

Angina, Unstable↗
PubMed1999

Pre-operative plasma levels of soluble fibrin polymers correlate with the development of deep vein thrombosis after elective neurosurgery.

The role of blood tests in identifying patients at high risk for post-operative venous thromboembolism is undefined. The aim of this study was to evaluate the correlation between pre-operative plasma levels of soluble fibrin polymers (SFP), as determined by a recently developed enzyme-linked immunosorbent assay (ELISA) assay (TpP), and the incidence of deep vein thrombosis (DVT) after elective neurosurgery. Blood samples for SFP assay were withdrawn on the day before surgery from 157 consecutive patients undergoing elective neurosurgery for brain or spinal tumour. Patients were randomized to subcutaneous enoxaparin (40 mg once daily) or placebo given for at least 7 days. All patients wore compression stockings. DVT was assessed by bilateral venography, performed on day 8 +/- 1. Thirty-four patients (21.7%) were found to have a DVT, proximal in 11 (7%) and isolated distal in 23. Patients with and without DVT had a plasma pre-operative SFP levels of 6.2 +/- 4.6 and 1.9 +/- 1.5 mg/ml respectively (mean +/- SD) (P < 0.001). SFP levels in patients with proximal and isolated distal DVT were 7.6 +/- 5.1 and 5.5 +/- 4.4 microg/ml, respectively (P = 0.22). SFP cut-off levels categorized patients into three classes of DVT incidence. The incidence of DVT was 7.4% (6 of 81) for SFP levels < 2 microg/ml, 20.4% (11 of 54) for levels between 2 and 4.5 microg/ml, and 77.3% (17 of 22) for levels > 4.5 microg/ml (P= 0.001, Cochran-Mantel-Haenszel test). We conclude that pre-operative SFP levels correlate with post-operative DVT in elective neurosurgery patients. Further studies are required to define whether pre-operative SFP measurement could be useful in patient management.

Adult↗
PubMed1998

Anticoagulant agents in the management of pulmonary embolism.

The anticoagulant agents most commonly used in the prevention and treatment of pulmonary embolism (PE) are unfractionated heparin, oral anticoagulants, and low molecular weight heparins (LMWHs). Unfractionated heparin at low fixed dose is the prophylactic regimen of choice for PE in patients undergoing general surgery or with serious medical diseases (low to moderate risk patients). In high risk patients perioperative prophylaxis with LMWHs or oral anticoagulants should be adopted. Therapy of pulmonary embolism should start with an intravenous bolus dose of 5000 U heparin followed by an infusion of 1250 U/h. Then the dose should be adjusted to maintain the aPTTX2-2.5 pre-treatment value. Heparin is continued for 7-10 days and is followed by oral anticoagulants for at least 3 months. Unfractionated heparin has some pharmacological limitations, mainly due to the aspecific binding to plasma proteins that limits its anticoagulant effect and causes the heparin resistance observed in some patients with PE and the inter-subject variability of the anticoagulant effect. Other antithrombotic agents such as LMWHs and selective thrombin inhibitors (hirudin and its analogues) do not aspecifically bind to plasma proteins. They have recently been used with promising results in the prevention and treatment of PE. Their definitive value in this clinical setting will be defined by the ongoing clinical trials.

Anticoagulants↗
PubMed1997

Recombinant hirudin in the prevention of venous thromboembolism in patients undergoing elective hip surgery.

Venous thromboembolism is a major cause of mortality and morbidity in patients undergoing orthopedic surgery. In these patients systemic prophylaxis with anticoagulants appears to be the most effective approach to reduce venous thromboembolic events. Low-molecular-weight heparins (LMWHs) are the prophylactic agents of choice in patients undergoing elective hip replacement. However, their use is still associated with a 15% incidence of deep vein thrombosis (DVT); hence, there is a need for potentially more effective agents. Among these, hirudin and other selective thrombin inhibitors have recently been evaluated. The main pharmacologic properties of recombinant hirudin and the clinical trials carried out with this agent in the prevention of DVT in patients undergoing elective hip replacement are reviewed in this article. Overall, the results of these clinical trials are quite promising; they actually indicate that a b.i.d. subcutaneous injection of 15 or 20 mg of recombinant hirudin is an effective and safe prophylactic approach. Hirudin was more effective than unfractionated heparin, given at a low fixed dose, in two clinical trials and of a LMWH in one clinical trial. However, further studies are required to define the role of recombinant hirudin in the prevention of venous thromboembolism in orthopedic surgery patients.

Elective Surgical Procedures↗
PubMed1981

Serum migration-inhibitory activity in infants with respiratory syncytial virus bronchiolitis.

Using an unidirectional leucocyte migration-inhibition (LMI) assay, we investigated the migration-inhibitory activity (LIF) in the sera of 25 infants who developed bronchiolitis following respiratory syncytial virus (RSV) infection. Blood samples for serum-LIF activity detection were obtained from patients the day after admission and two weeks later. The LMI assay revealed serum-LIF activity in 17 (68%) blood samples taken during the acute phase of the disease. In contrast, no inhibition was found in the convalescent blood samples with the exception of 5 (20%). This difference was statistically significant (chi2 = 9.82; P less than 0.005). As positive serum-LIF test is a good in vitro correlate of cell-mediated immunity, our results suggest that cell-mediated hypersensitivity reactions occur during the clinical course of RSV bronchiolitis. These findings are consistent with the hypothesis that alterations of RSV-specific cell-mediated immune mechanisms may be involved in the pathogenesis of this illness.

Bronchiolitis, Viral↗
PubMedDate not supplied

Prevention of venous thromboembolism in high risk patients.

BACKGROUND AND OBJECTIVE: Venous thromboembolism includes two closely related clinical manifestations: deep vein thrombosis (DVT), more commonly of the lower limbs, and pulmonary embolism. Pulmonary embolism is the most common cause of preventable death in hospitalized patients. The definition of the risk factors for venous thromboembolism should allow to adopt the most suitable prophylactic regimen. Determinants for the risk of venous thromboembolism are patient risk factors, both clinical and molecular, and the clinical setting. In this article the prophylactic regimens most widely employed in the prevention of venous thromboembolism in high-risk clinical settings with be reviewed. Then, the available guidelines for the management of thrombophilic patients will be given. INFORMATION SOURCES: The authors have been working in this field contributing original papers. In addition, the material examined in this review article includes papers published in the journals covered by the Science Citation Index and Medline. STATE OF ART AND PERSPECTIVES: Pharmacological prophylaxis is an effective approach for reducing morbidity and mortality from venous thromboembolism. Nevertheless, prophylaxis for venous thromboembolism is under employed because the incidence of venous thromboembolism is underestimated and there is fear of bleeding side effects. Adopting the proper prophylactic strategy for venous thromboembolism requires defining the patient risk factor. Determinants for the risk of venous thromboembolism are patient risk factors, both clinical and molecular, and the clinical setting. The risk connected with the clinical setting is the only risk defined by properly performed epidemiological studies. High-risk clinical settings are major orthopedic surgery, elective neurosurgery, spinal cord injury, cancer surgery and multiple trauma. The most effective anticoagulant regimens in the prevention of venous thromboembolism in high-risk patients are adjusted-dose unfractionated heparin, low molecular weight heparins (LMWHs) and oral anticoagulants. LMWHs are as effective and safe as the other two agents, but they do not require laboratory monitoring. On the other hand, LMWHs are more expensive than unfractionated heparin and warfarin. The use of effective agents still leaves the patients with a high prevalence of venous thromboembolism. Hence the search for more effective agents such as selective thrombin inhibitors like hirudin and its analogues. In patients undergoing elective hip surgery, hirudin has been recently shown to be more effective than low-dose unfractionated heparin and the LMWH enoxaparin.

Adult↗