Natural anticoagulants limit lipopolysaccharide-induced pulmonary coagulation but not inflammation

Pulmonary coagulopathy and hyperinflammation may contribute to an adverse outcome in sepsis. The present study determines the effects of natural inhibitors of coagulation on bronchoalveolar haemostasis and inflammation in a rat model of endotoxaemia. Male Sprague-Dawley rats were randomised to treatment with normal saline, recombinant human activated protein C (APC), plasma-derived antithrombin (AT), recombinant human tissue factor pathway inhibitor (TFPI), heparin or recombinant tissue plasminogen activator (tPA). Rats were intravenously injected with lipopolysaccharide (LPS), which induced a systemic inflammatory response and pulmonary inflammation. Blood and bronchoalveolar lavage were obtained at 4 and 16 h after LPS injection, and markers of coagulation and inflammation were measured. LPS injection caused an increase in the levels of thrombin-AT complexes, whereas plasminogen activator activity was attenuated, both systemically and within the bronchoalveolar compartment. Administration of APC, AT and TFPI significantly limited LPS-induced generation of thrombin-AT complexes in the lungs, and tPA stimulated pulmonary fibrinolytic activity. However, none of the agents had significant effects on the production of pulmonary cytokines, chemokines, neutrophil influx and myeloperoxidase activity. Natural inhibitors of coagulation prevent bronchoalveolar activation of coagulation, but do not induce major alterations of the pulmonary inflammatory response in rat endotoxaemia.

[Prevention of thrombosis in traumatology]

Venous thromboembolism is frequent in trauma patients and often runs an asymptomatic course. Prophylaxis in these patients, who often have an increased risk of bleeding, deserves extra attention. After injuries to the lower extremities, low molecular weight heparin is advised during the period of immobilisation. Following hip-fracture surgery, fondaparinux is indicated for 4 weeks. In polytrauma and neurotrauma patients, low molecular weight heparin has shown the best results. Thrombosis prophylaxis also seems to be indicated in burn patients.

[Deep-vein thrombosis and pulmonary embolism due to air travel]

In recent years, the association between air travel and the incidence of deep-vein thrombosis or pulmonary embolism has become clearer. Epidemiologic studies reveal an increased relative risk of thromboembolism after flights of more than 8 hours and especially in subjects at higher risk for this disease, due, for example, to congenital thrombophilia or the use of oral contraceptives. However, the absolute risk of deep-vein thrombosis or pulmonary embolism after prolonged air travel is very small. Studies have shown that a combination of factors present during prolonged air travel may account for increased activation of coagulation. There is no definitive proof that elastic stockings are effective in reducing the incidence of clinically relevant thromboembolism during air travel. Acetylsalicylic acid is not effective in the prevention of thrombosis during air travel and may be dangerous. Prophylactic subcutaneous low molecular weight heparin may be effective to prevent air travel-associated thrombosis. However, pending more solid evidence, this strategy should only be used cautiously, e.g. only in patients with a high risk of thrombosis who are planning a long flight.

Tissue factor serum levels and the risk of future coronary artery disease in apparently healthy men and women: the EPIC-Norfolk prospective population study

INTRODUCTION

Tissue factor (TF) has been implicated in coronary artery disease (CAD). High levels of circulating TF are found in patients with acute atherothrombotic events. Whether high serum TF levels predict risk of future CAD independent of known risk factors remains unknown.

METHODS

We conducted a prospective case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk population study. Cases (n=1037) were apparently healthy men and women, aged 45-79 years, who developed fatal or non-fatal CAD during follow-up. Controls (n=2005) were matched by age, sex, and enrolment time. Serum TF levels were measured using high-affinity antibodies.

RESULTS

In men, median TF levels were not significant higher in cases than in controls (59.0 pg mL-1, range: 16.7-370.4 vs. 54.9 pg mL-1, range: 16.2-452.4). In women, median TF levels were not significant higher in controls than in cases (73.4 pg mL-1, range: 16.7-492.3 vs. 50.5 pg mL-1, range: 16.5-376.7). The incidence of smoking was about double in the lowest compared with the highest TF quartile. Correcting for sex, age, body mass index, smoking, diabetes, systolic blood pressure, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol and C-reactive protein levels, the risk of future CAD was 1.05 (95% CI: 0.81-1.36) for people in the highest TF quartile, compared with those in the lowest (P-value for linearity=0.8).

CONCLUSION

High levels of serum TF were not independently associated with an increased risk of future CAD in apparently healthy individuals.

Vagus nerve stimulation inhibits activation of coagulation and fibrinolysis during endotoxemia in rats

BACKGROUND

Sepsis and endotoxemia are associated with concurrent activation of inflammation and the hemostatic mechanism, which both contribute to organ dysfunction and death. Electrical vagus nerve stimulation (VNS) has been found to inhibit tumor necrosis factor (TNF)-alpha release during endotoxemia in rodents.

OBJECTIVE

To determine the effect of VNS on activation of coagulation and fibrinolysis.

METHODS

Rats received a sublethal i.v. dose of lipopolysaccharide (LPS) after electrical VNS or sham stimulation. Activation of coagulation and fibrinolysis, as well as cytokine release, was measured before LPS injection and 2, 4 and 6 h thereafter.

RESULTS

LPS induced activation of the coagulation system (increases in the plasma concentrations of thrombin-antithrombin complexes and D-dimer, and a decrease in antithrombin) and biphasic changes in the fibrinolytic system [early rises of plasminogen activator activity and tissue-type plasminogen activator, followed by a delayed increase in plasminogen activator inhibitor type 1 (PAI-1)]. VNS strongly inhibited all LPS-induced procoagulant responses and more modestly attenuated the fibrinolytic response. In addition, VNS attenuated the LPS-induced increases in plasma and splenic concentrations of the proinflammatory cytokines TNF-alpha and interleukin-6 (IL-6), while not influencing the release of the anti-inflammatory cytokine IL-10.

CONCLUSION

These data illustrate a thus far unrecognized effect of VNS and suggest that the cholinergic anti-inflammatory pathway not only impacts on inflammation but also on the coagulant-anticoagulant balance.

Short-term and long-term mortality in very elderly patients admitted to an intensive care unit

OBJECTIVE

To report short-term and long-term mortality of very elderly ICU patients and to determine independent risk factors for short-term and long-term mortality

DESIGN AND SETTING

Retrospective cohort study in the medical/surgical ICU of a tertiary university teaching hospital.

PATIENTS

578 consecutive ICU patients aged 80 years or older.

RESULTS

Demographic, physiological, and laboratory values derived from the first 24h after ICU admission. ICU mortality of unplanned surgical (34.0%) and medical patients (37.7%) was higher than that of planned surgical patients (10.6%), as was post-ICU hospital mortality (26.5% and 29.7% vs. 4.4%). Mortality 12 months after hospital discharge, including ICU and hospital mortality, was 62.1% in unplanned surgical and 69.2% in medical patients vs. 21.6% in planned patients. Only median survival of planned surgical patients did not differ from survival in the age- and gender-matched general population. Independent risk factors for ICU mortality were lower Glasgow Coma Scale score, higher SAPS II score, the lowest urine output over 8 h, abnormal body temperature, low plasma bicarbonate levels, and higher oxygen fraction of inspired air. High urea concentrations and admission type were risk factors for hospital mortality, and high creatinine concentration was an independent risk factor for 12-month mortality.

CONCLUSION

Mortality in very elderly patients after unplanned surgical or medical ICU admission is higher than after planned admission. The most important factors independently associated with ICU mortality were related to the severity of illness at admission. Long-term mortality was associated with renal function.

[Perioperative thromboprophylaxis--for the immobilisation period, potential extension beyond hospitalisation]

Antithrombotic prophylaxis of venous thromboembolism after surgery, usually by means of subcutaneous administration of(low-molecular-weight) heparin, drastically reduces the incidence of postoperative thrombosis and pulmonary embolism. Therefore, this intervention is advocated in various national and international guidelines. A questionnaire-based study in this issue shows that 99% of surgeons in the Netherlands strictly adhere to these guidelines. Interestingly, the duration of thromboprophylaxis is much less clear and is usually restricted to the duration of hospitalisation. In view of the increasing number of surgical procedures in short-stay or even outpatient settings, it is possible that extended prophylaxis for perioperative thrombosis should be considered, particularly in patients with risk factors for thrombosis, such as the presence of malignant disease.

[Continuous subcutaneous insulin infusion is sometimes a good choice in case of poorly regulated diabetes mellitus type I]

Continuous subcutaneous insulin infusion (CSII) was initiated in 3 patients with diabetes mellitus type I who experienced difficulties with their glucose regulation: a woman aged 26 years and two men aged 56 and 41 years. 2 patients responded very well, while the third, the youngest man, did not benefit. Although interest in CSII has been growing in recent years, considerable uncertainty exists about which patients will benefit from it. In most studies, patients have attained a lower HbA,, and fewer blood glucose fluctuations. Recently, the advantages of CSII have been confirmed in 2 large studies in patients with diabetes mellitus type I. Motivated patients in poor glycaemic control seem to benefit most from CSII. Some questions remain, especially whether these advantages can be confirmed in studies comparing CSII with injection regimens using the new long-acting insulin analogues. Motivated patients in poor control and those with an unpredictable daily life, needing a flexible mode of therapy, should not be denied a trial of CSII.

[Admission of elderly patients to intensive care]

Elderly patients have an increased probability of dying after treatment in an intensive care unit (ICU), compared with younger patients. The risk of dying is largely determined by the admission type (patients with planned admissions have a better prognosis than those with unplanned admissions), severity of illness and functional status prior to admission. Elderly patients surviving ICU often experience a decline in functional status. No data are available on the factors that predict functional outcome. Elderly patients do not necessarily prefer life-sustaining treatment to palliative care. The willingness to undergo ICU treatment depends on the likelihood of survival and beneficial functional outcome. New prognostic models should be developed specifically to predict both survival and functional outcome in individual elderly patients after admission to ICU.

[Clinical reasoning and decision making in practice: a 30-year-old man with unexplained coma]

A 30-year-old man known to have a factor-IX deficiency was presented at the emergency department with unexplained coma. After immediate treatment with factor IX, a CT-scan of the brain revealed no intracerebral haemorrhage. However, blood tests showed severe hyponatraemia, low serum osmolarity and high urine-sodium excretion consistent with the Syndrome of Inappropriate Antiduretic Hormone Secretion (SIADH). Therapy with hypertonic saline was instituted resulting in a gradual rise in the serum-sodium concentration. The cause of the hyponatraemia however remained unclear. After repeat history taking the patient mentioned the use of desmopressin for nocturia. Hyponatraemia as a complication of desmopressin use occurs in 8% of adult patients treated for nocturia. Direct availability of a patient's drug history, by means of an electronic record for instance, could avoid unnecessary tests and delay in diagnosis.

Clinical subtypes of delirium and their relevance for daily clinical practice: a systematic review

BACKGROUND

Delirium is a disorder that besides four essential features consists of different combinations of symptoms. We reviewed the clinical classification of clusters of symptoms in two or three delirium subtypes. The possible implications of this subtype classification may be several. The investigation and exploration of clinical subtypes of delirium may provide information concerning the etiology, the pathogenesis, and the prognosis of delirium, but also may have therapeutic consequences.

METHODS

We searched several database for English-language articles. Selected articles were cross-checked for other relevant publications.

DATA SYNTHESIS AND CONCLUSION

We conducted a systematic review and retrieved ten clinical studies. The studies described in this review show different results, partly due to methodological problems and possibly by lack of a standard classification for delirium subtypes. According to the present literature a useful and reproducible method to classify (patterns of) symptoms in delirium subtypes seems to be the general rating of and division in to psychomotor subtypes. The Memorial Delirium Assessment Scale (MDAS) and the Dublin Delirium Assessment Scale (DAS) appear to be reliable methods, together with the new version of the Delirium Rating Scale (DRS-R-98).

Disturbed alveolar fibrin turnover during pneumonia is restricted to the site of infection

Severe infection is associated with profound alterations in the systemic haemostatic balance, with activation of coagulation and suppressed fibrinolysis. Within the alveolar compartment, similar disturbances have been described during pulmonary inflammation. The current authors investigated whether local haemostasis was influenced during ventilator-associated pneumonia (VAP). In five patients with unilateral VAP, bronchoalveolar lavage fluid (BALF) was obtained from both the infected site (as identified on chest radiograph) and the contralateral noninfected lung (with no clinical or radiographic abnormalities). Markers for coagulation and fibrinolysis were compared between infected and noninfected lungs. A total of 10 healthy volunteers and 10 mechanically ventilated patients without pneumonia served as controls. Strong activation of coagulation (high levels of thrombin-antithrombin complexes, soluble tissue factor and factor VIIa) was detected in BALF from infected lungs, compared with that from noninfected lungs and controls. Furthermore, in infected lungs, fibrinolysis was depressed, with high levels of plasminogen activator inhibitor type 1. In conclusion, ventilator-associated pneumonia is characterised by a hypercoagulant state at the site of infection.

Treatment effects of drotrecogin alfa (activated) in patients with severe sepsis with or without overt disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a serious condition associated with sepsis. Clinical management of DIC is hampered by lack of clear diagnostic criteria. The International Society on Thrombosis and Haemostasis (ISTH) has proposed a diagnostic scoring algorithm for overt DIC based on routine laboratory tests. The objective was to assess a modified version of the ISTH scoring system and determine the effect of drotrecogin alfa (activated) (DrotAA, recombinant human activated protein C) on patients with DIC. The large database from the PROWESS clinical trial in severe sepsis was retrospectively used to assess a modified ISTH scoring system. Baseline characteristics and treatment effects of DrotAA were evaluated. At baseline, 29% (454/1568) of patients had overt DIC. Overt DIC was a strong predictor of mortality, independent of APACHE II score and age. Placebo-treated patients with overt DIC had higher mortality than patients without (43 vs. 27%). DrotAA-treated patients with overt DIC had a trend towards greater relative risk reduction in mortality than patients without (29 vs. 18%, P = 0.261) but both groups had greater relative risk reduction than placebo-treated patients. Serious bleeding rates during DrotAA infusion in patients with and without overt DIC were slightly increased (P = 0.498), compared with placebo, while clinically overt thrombotic events during the 28-day period were slightly reduced (P = 0.144). Modified ISTH overt DIC scoring may be useful as an independent assessment for identifying severe sepsis patients at high risk of death with a favorable risk/benefit profile for DrotAA treatment. Patients without overt DIC also received significant treatment benefit.

Quality of life and metabolic control in patients with diabetes mellitus type 1 treated by continuous subcutaneous insulin infusion or multiple daily insulin injections

OBJECTIVE

To assess the quality of life and metabolic control in patients with diabetes mellitus type 1 on continuous subcutaneous insulin infusion (CSII) in comparison with patients on multiple daily insulin injections (MDII).

RESEARCH DESIGN AND METHODS

The study included 49 patients (13 males, 36 females), aged 41.4+/-11.3 years (mean+/-SD) on CSII for >1 year and 79 patients (43 males, 36 females), aged 43.1+/-14.8 years on MDII for >1 year, from three Dutch diabetic clinics. There were no statistically significant differences in duration of diabetes, social class, level of education, marital status, smoking or recent admissions to hospital. The questionnaires used were a Diabetes Quality of Life scale adapted from the DCCT, the Diabetes Satisfaction Questionnaire (DTSQ), and the WHO Well-Being Questionnaire. HbA1c was measured with an HPLC method (reference range 4.3 to 6.1 %).

RESULTS

Using two-sided t-tests no statiscally significant differences were found between the patients on CSII and MDII with respect to quality of life (version A (<30 years) 4.32+/-0.22 vs 4.20+/-0.30; version B (> or =30 years) 4.18+/-0.25 vs 4.29+/-0.28), well-being (48.59+/-9.23 vs 50.99 +/-8.70), satisfaction with treatment (5.10+/-0.69 vs 5.15+/-0.71) and HbA1c (8.14+/-1.51 vs 8.47+/-1.40). Frequency of daily blood glucose monitoring was slightly higher in CSII than in MDII patients (4.52+/-1.19 vs 3.60+/-1.47; p<0.0001).

CONCLUSION

The present data indicate that patients on CSII have similar QoL based on questionnaires when compared with patients on MDII. These data suggest that in patients with less optimal control on MDII, converting the treatment strategy to CSII is not associated with decreased quality of life.

[Diagnostic and pharmaco-therapeutic options in acute severe blood loss]

In patients with excessive blood loss, coagulation is compromised by hypothermia, metabolic acidosis due to impaired tissue perfusion, loss of coagulation factors and platelets while their consumption is increased, and by massive infusion with plasma expanders. Currently available laboratory tests are insufficiently reliable and too time-consuming to enable the evaluation of the effect of pharmaco-therapeutic interventions during severe blood loss. Several haemostatic drugs appear to be effective in the treatment of blood loss after elective surgery, but have been insufficiently investigated in patients with severe bleeding. A rational transfusion policy entailing the use of sufficient amounts of plasma is necessary in the treatment of patients with severe bleeding.

Psychological treatment of eating disorders. A review of the literature

The aim of this study is to review the existing literature (PubMed database) on the psychological treatments for eating disorders (EDs), subdivided in individual, group and family therapies. Moreover new approaches and directions in this field are addressed. An extensive literature review is performed to identify the psychological treatment trials in anorexia nervosa (AN) and bulimia nervosa (BN) published over the past 2 decades. Eighty-two studies focused on psychotherapeutic treatment of EDs are reviewed. Only a minor part of these studies are randomised and controlled. While there is evidence of the efficacy of cognitive behavioral therapy (CBT), this is still missing for other psychotherapeutic approaches. However, there is general agreement about the importance of psychotherapy in multimodal treatments. There is still a need for a shared concept of outcome in EDs, since the efficacy of psychological treatment is greatly influenced by the definition of outcome adopted (concerning symptoms, psychosocial functioning, personality).

Beta-receptor blockade decreases elevated plasma levels of factor VIII:C in patients with deep vein thrombosis

BACKGROUND

An elevated plasma level of factor VIII:C (FVIII:C) is a strong and dose-dependent risk factor for venous thromboembolism (VTE). The cause of elevated FVIII:C in patients with thrombophilia is as yet unknown. FVIII:C increases significantly after infusion of epinephrine, vasopressin or physical exercise. The aim of the present study was to investigate whether beta-receptor blockade will lower sustained elevated FVIII:C in patients with VTE.

METHODS AND RESULTS

Two cohorts of patients with documented deep vein thrombosis and an elevated FVIII:C (>175 IU dL(-1)) and healthy volunteers, were studied. One cohort was treated with the beta-receptor blocker, whereas the other cohort served as non-treatment controls. The patient treatment group and healthy volunteers were given 40 mg propranolol, thrice daily, for 14 days. The mean baseline level of FVIII:C was 220 IU dL(-1) and 102 IU dL(-1) in patients and healthy volunteers, respectively. After 2 weeks of propranolol a significant 23% reduction of FVIII:C (- 52 IU dL(-1); 95%CI:[-65; -39]) compared with no change over time in the patient no- treatment group (-1.8 IU dL(-1); 95%CI:[-34; 30]). After discontinuation of propranolol FVIII:C returned to its initial high level. In healthy volunteers propranolol had no effect on the plasma concentration of FVIII:C.

CONCLUSION

This study demonstrates that in patients with VTE a sustained elevated FVIII:C concentration can be decreased with the use of propranolol. This observation may be of potential clinical relevance, since it has been shown that each increase of 10 IU dL(-1) in FVIII:C concentration enhanced the risk of a recurrent VTE by 24%.

[Sepsis, a complicated syndrome with major medical and social consequences]

Severe sepsis is a life-threatening complication of infection. Due to associated organ-failure treatment in an Intensive Care Unit is usually indicated. Since sepsis is defined by the combination and progression of clinical events, correct definitions are essential to enable good comparison between study results and determination of suitable treatment. Severe sepsis is associated with a mortality of 20-60% and decreases the health-related quality of life in survivors. It is estimated that annually in the Netherlands 9000 patients are admitted to an Intensive Care Unit with severe sepsis. Direct medical costs of severe sepsis are estimated at [symbol: see text] 19,500 per patient. Costs correlate strongly with the length of stay. Annually Euro dollar 168,6 million is spent on severe sepsis, which represents 0.5% of all health-care costs and 1.7% of the annual hospital budget in the Netherlands.

Critical bleeding in surgery: conventional therapy and new prospects

Perioperative bleeding is one of the most frequent complications of surgery. Management of bleeding consists of local control (surgical or endoscopic hemostasis), measures to retain adequate circulation and proper transfusion procedures. In this review we will discuss various agents with a prohemostatic potential and their efficacy to reduce perioperative blood loss. Desmopressin increase the plasma concentration of Von Willebrand factor giving an augmentation of primary hemostasis. The use of recombinant activated factor VII is based on the evidence that activation of coagulation in vivo predominantly proceeds by the tissue factor/factor VII (a) pathway. Agents that exerts anti-fibrinolytic activity are aprotinin and the group of lysine analogues. The prohemostatic effect is due to inhibition of fibrinolysis and to a protective effect on platelets. Prohemostatic therapy may achieve an improvement of hemostasis, by amelioration of primary hemostasis, stimulation of fibrin formation or inhibition of fibrinolysis and seems to be effective in reducing perioperative blood loss and transfusion requirements.

[Extent and quality of anti-coagulation treatment with coumarin derivatives by the Dutch Thrombosis Services]

OBJECTIVE

To obtain an impression of the extent and quality of the anti-coagulation treatment with coumarin derivatives carried out by the Thrombosis Services in the Netherlands.

DESIGN

Descriptive.

METHOD

Data were drawn from the medical annual reports of 62 of the 63 Thrombosis Services in the Netherlands over the period 1998-2002. In 2002 the Thrombosis Services treated 325,072 patients and performed 4,469,730 INR laboratory tests. The half-yearly figures produced by the Thrombosis Services were calculated as an average percentage per year per thrombosis service and then recalculated as a percentage per year.

RESULTS

Seventy-three per cent of the patients were treated for an arterial and 27% for a venous indication. Depending on the required intensity of anticoagulation a mean of 74-78% of the long-term treated patients fell within the therapeutic range and a mean of 6-10% below. The mean number of major bleedings per 100 treatment years was 1.0. A mean of 79% of the patients was treated with acenocoumarol and 21% with phenprocoumon. When acenocoumarol was used, a mean of 72-77% fell within the therapeutic range and in the case of phenprocoumon 79-82%. In the last few years the number of patients had increased due to a growing number of patients treated for atrial fibrillation. The percentages of INR within the therapeutic range were unchanged or showed a slight increase.

CONCLUSION

The quality of the anticoagulation therapy with coumarin derivatives was good or acceptable.

Local activation of coagulation and inhibition of fibrinolysis in the lung during ventilator associated pneumonia

BACKGROUND

Fibrin deposition is a hallmark of pneumonia. To determine the kinetics of alterations in local coagulation and fibrinolysis in relation to ventilator associated pneumonia (VAP), a single centre prospective study of serial changes in pulmonary and systemic thrombin generation and fibrinolytic activity was conducted in patients at risk for VAP.

METHODS

Non-directed bronchial lavage (NBL) was performed on alternate days in patients expected to require mechanical ventilation for more than 5 days. A total of 28 patients were studied, nine of whom developed VAP.

RESULTS

In patients who developed VAP a significant increase in thrombin generation was observed in the airways, as reflected by a rise in the levels of thrombin-antithrombin complexes in NBL fluid accompanied by increases in soluble tissue factor and factor VIIa concentrations. The diagnosis of VAP was preceded by a decrease in fibrinolytic activity in NBL fluid. Indeed, before VAP was diagnosed clinically, plasminogen activator activity levels in NBL fluid gradually declined, which appeared to be caused by a sharp increase in NBL fluid levels of plasminogen activator inhibitor 1.

CONCLUSION

VAP is characterised by a shift in the local haemostatic balance to the procoagulant side, which precedes the clinical diagnosis of VAP.

Systematic review of survival after acute mesenteric ischaemia according to disease aetiology

BACKGROUND

Differentiation of acute mesenteric ischaemia on the basis of aetiology is of great importance because of variation in disease progression, response to treatment and outcome. The aim of this study was to analyse the published data on survival following acute mesenteric ischaemia over the past four decades in relation to disease aetiology and mode of treatment.

METHOD

A systematic review of the available literature from 1966 to 2002 was performed.

RESULTS

Quantitative analysis of data derived from 45 observational studies containing 3692 patients with acute mesenteric ischaemia showed that the prognosis after acute mesenteric venous thrombosis is better than that following acute arterial mesenteric ischaemia; the prognosis after mesenteric arterial embolism is better than that after arterial thrombosis or non-occlusive ischaemia; the mortality rate following surgical treatment of arterial embolism and venous thrombosis (54.1 and 32.1 per cent respectively) is less than that after surgery for arterial thrombosis and non-occlusive ischaemia (77.4 and 72.7 per cent respectively); and the overall survival after acute mesenteric ischaemia has improved over the past four decades.

CONCLUSION

There are large differences in prognosis after acute mesenteric ischaemia depending on aetiology. Surgical treatment of arterial embolism has improved outcome whereas the mortality rate following surgery for arterial thrombosis and non-occlusive ischaemia remains poor.

[Job-sharing in postgraduate medical training: not automatically a nice duet]

Part-time work is an increasingly common phenomenon amongst medical professionals. Therefore many postgraduate training programmes for resident physicians also offer the opportunity of part-time work, which is usually in the form of an 80% full-time equivalent post. A new initiative has created the possibility of job-sharing, in which each of the participants fulfills 50% of one training position. Although the experience of the participants is mainly positive, it is unclear how this development will impact the quality of patient care and how it will affect the fulfillment of the training objectives. A more systematic evaluation of job-sharing in postgraduate medical training programmes is required to clarify these points.

[Reasons why patients do or do not participate in clinical trials; a systemic review of the literature]

OBJECTIVE

To assess the factors that may influence a patient's consent to participate in a clinical trial.

DESIGN

Systematic literature survey.

METHOD

Studies on the characteristics of patients, trials, the physicians requesting informed consent and the informed consent procedures were looked for in Medline, Embase, and Cinahl. Articles published in English, German, Dutch or French in the period 1980-2002 and originating in Europe, the United States, Canada, New Zealand or Australia were included. Studies on non-adults, healthy experimental subjects or less than 30 patients were excluded.

RESULTS

Thirty suitable studies were retrieved. Factors that may affect the granting of consent to participate in a clinical trial included: uncertainty of the patient, randomisation and the use of a placebo, the relationship between the person asking for informed consent and the patient, and the dissemination of information during the informed consent procedure. Since these factors are often interrelated, no single factor could be identified as decisive for participation in a clinical trial; they can influence the decision of the patient to participate in a trial in either a positive or a negative direction.

CONCLUSION

Optimalization of the information concerning informed consent, the way the information is provided and the attitude of the person requesting informed consent are important and sometimes decisive factors that may determine the participation process.

Recombinant nematode anticoagulant protein c2, an inhibitor of tissue factor/factor VIIa, attenuates coagulation and the interleukin-10 response in human endotoxemia

The tissue factor-factor (F)VIIa complex (TF/FVIIa) is responsible for the initiation of blood coagulation under both physiological and pathological conditions. Recombinant nematode anticoagulant protein c2 (rNAPc2) is a potent inhibitor of TF/FVIIa, mechanistically distinct from tissue factor pathway inhibitor. The first aim of this study was to elucidate the pharmacokinetics and pharmacodynamics of a single intravenous (i.v.) dose of rNAPc2. The second aim was to study its effect on endotoxin-induced coagulation and inflammation. Initially, rNAPc2 was administered to healthy volunteers in three different doses. There were no safety concerns and the pharmacokinetics were consistent with previous studies, in which rNAPc2 was administered subcutaneously. rNAPc2 elicited a dose-dependent reduction of the endogenous thrombin potential and a selective prolongation of prothrombin time. Subsequently, the effect on endotoxin-induced coagulation and inflammation was studied. The administration of rNAPc2 completely blocked the endotoxin-induced thrombin generation, as measured by plasma prothrombin fragment F1+2. The endotoxin-induced effect on fibrinolytic parameters such as plasmin-antiplasmin complexes and plasminogen activator inhibitor type 1 was not affected by rNAPc2. The administration of rNAPc2 attenuated the endotoxin-induced rise in interleukin (IL)-10, without affecting the rise in other cytokines. In conclusion, rNAPc2 is a potent inhibitor of TF/FVIIa, which was well tolerated and could safely be used intravenously in this Phase I study in healthy male volunteers. A single i.v. dose rNAPc2 completely blocked endotoxin-induced thrombin generation without affecting the fibrinolytic response. In addition, rNAPc2 attenuated the endotoxin-induced rise in IL-10, without affecting the rises in other cytokines.

Individualized duration of oral anticoagulant therapy for deep vein thrombosis based on a decision model

BACKGROUND

The optimal duration of oral anticoagulant therapy for patients with a first episode of deep vein thrombosis (DVT) is still a matter of debate. However, according to the ACCP consensus strategy a limited stratification in treatment duration is advocated, i.e. 3 months for patients with a transient risk factor and 1 year or longer for patients with recurrent disease or a consistent risk factor such as thrombophilia or cancer. This consensus strategy is founded on the mean optimal duration of therapy obtained in large cohorts of patients and is mainly based on the risk of recurrent venous thromboembolism (VTE), with only minimal consideration for the patient's bleeding risk.

OBJECTIVE

The aim of this study is to optimize the anticoagulant treatment strategy with vitamin K antagonists for the individual patient with DVT.

METHODS

Based on an extensive literature study, a mathematical model was constructed to balance the risk of recurrent VTE against the risk of major hemorrhagic complications. The following parameters are incorporated in the model: baseline estimates and risk factors for recurrent VTE and bleeding, clinical course of DVT, and efficacy of treatment with vitamin K antagonists. With the use of these parameters, the risk for a recurrent VTE and a bleeding episode can be calculated for the individual patient. The optimal duration of anticoagulant therapy can be defined as the timepoint at which the benefit of treatment (prevention of VTE) is counterbalanced by its risk (bleeding).

RESULTS/CONCLUSIONS

How long a patient should receive anticoagulant treatment is a matter of balancing the benefits and risks of treatment. The model shows that the optimal treatment duration varies greatly from patient to patient according to the patient's unique bleeding and recurrence risk.

Recombinant factor VIIa reverses the in vitro and ex vivo anticoagulant and profibrinolytic effects of fondaparinux

BACKGROUND

Fondaparinux is a synthetic pentasaccharide, which selectively inhibits coagulation factor (F) Xa, and is registered for prevention of venous thromboembolism following hip fracture, hip replacement, and knee replacement surgery. Recently, it was shown that recombinant FVIIa (rFVIIa) reverses anticoagulant effects of fondaparinux in healthy volunteers.

OBJECTIVES

In this study, we have explored the in vitro and ex vivo effects of rFVIIa on clot formation and thrombin-activatable fibrinolysis inhibitor (TAFI)-mediated down-regulation of fibrinolysis after fondaparinux administration.

METHODS

In vitro clot lysis assays were performed in pooled normal plasma from healthy volunteers to which fondaparinux was added, and in serial samples from healthy volunteers who received a single bolus dose of fondaparinux, a single bolus dose of rFVIIa, or both.

RESULTS AND CONCLUSIONS

Fondaparinux significantly delayed clot formation, and clot lysis was significantly increased due to decreased activation of TAFI. Addition of recombinant FVIIa corrected the inhibited clot formation induced by fondaparinux, and the acceleration of clot lysis was partially reversed. In vivo administration of fondaparinux (10 mg) to healthy volunteers similarly resulted in accelerated plasma clot lysis. Subsequent administration of rFVIIa (90 microg kg(-1)) normalized the clot lysis time up to 6 h postadministration. rFVIIa might be a good therapeutic option in patients treated with fondaparinux who develop bleeding complications, since both clot formation as well as fibrinolytic resistance are improved.