Effect of age on the performance of a diagnostic strategy based on clinical probability, spiral computed tomography and venous compression ultrasonography

A Qualitative Study to Appraise Patients and Family Members Perceptions, Knowledge, and Attitudes towards Venous Thromboembolism Risk

Objective

This study aimed to examine perception, knowledge and concerns developed by patients and their family as regards venous thromboembolism (VTE) risk.

Methods

We conducted a qualitative study. Participants were: (1) patients with unprovoked VTE with either factor V Leiden mutation or G20210A prothrombin gene mutation or not; and (2) their first-degree relatives. Interviews took place mostly at Brest University Hospital. Participants produced narratives of the patient’s illness, stressing their perception of the disorder, its mechanisms, etiology, circumstances and risk factors. Interviews were audiotaped and transcribed verbatim. On an ongoing basis, central themes were identified and data from narratives were categorized by these themes.

Results

A total of ten patients and 25 first-degree relatives were interviewed. Analyses of patient’s narratives suggested 4 main themes: (1) concerns about initial symptoms and suspicion of VTE. The longer the duration of the initial phase, the more likely anxiety took place and persisted after diagnosis; (2) underestimation of potential life-threatening episode once being managed in emergency; (3) possible biographical disruption with inability to cope with the event; and (4) secondary prevention attitudes motivated by remains of the episode and favoring general prevention attitudes. Analyses of the first-degree relatives narratives suggested 3 main themes: (1) common interpretation of the VTE episode shared within the family; (2) diverse and sometimes confusing interpretation of the genetic status; and, (3) interpretation of clinical signs linked to VTE transmission within the family.

Conclusions

Construction of the risk of VTE is based on patient’s initial experience and shared within the family. Collection of narratives illustrates the gap between these perceptions and current medical knowledge. These results support the need to collect the perceptions of the VTE episode and its consequences, as a prerequisite to any health education process.

Validation of the Oudega diagnostic decision rule for diagnosing deep vein thrombosis in frail older out-of-hospital patients

OBJECTIVE

We aimed to validate the Oudega diagnostic decision rule-which was developed and validated among younger aged primary care patients-to rule-out deep vein thrombosis (DVT) in frail older outpatients.

METHODS

In older patients (>60 years, either community dwelling or residing in nursing homes) with clinically suspected DVT, physicians recorded the score on the Oudega rule and d-dimer test. DVT was confirmed with a composite reference standard including ultrasonography examination and 3-month follow-up. The proportion of patients with a very low probability of DVT according to the Oudega rule (efficiency), and the proportion of patients with symptomatic venous thromboembolism during 3 months follow-up within this 'very low risk' group (failure rate) was calculated.

RESULTS

DVT occurred in 164 (47%) of the 348 study participants (mean age 81 years, 85% residing in nursing homes). The probability of DVT was very low in 69 patients (Oudega score ≤3 points plus a normal d-dimer test; efficiency 20%) of whom four had non-fatal DVT (failure rate 5.8%; 2.3-14%). With a simple revised version of the Oudega rule for older suspected patients, 43 patients had a low risk of DVT (12% of the total population) of whom only one had DVT (failure rate 2.3%; 0.4-12%).

CONCLUSIONS

In older suspected patients, application of the original Oudega rule to exclude DVT resulted in a higher failure rate as compared to previous studies. A revised and simplified Oudega strategy specifically developed for elderly suspected patients resulted in a lower failure rate though at the expense of a lower efficiency.

Pulmonary embolism

Pulmonary embolism (PE) remains one of the most challenging medical diseases in the emergency department. PE is a potentially life threatening diagnosis that is seen in patients with chest pain and/or dyspnea but can span the clinical spectrum of medical presentations. In addition, it does not have any particular clinical feature, laboratory test, or diagnostic modality that can independently and confidently exclude its possibility. This article offers a review of PE in the emergency department. It emphasizes the appropriate determination of pretest probability, the approach to diagnosis and management, and special considerations related to pregnancy and radiation exposure.

Systematic review: diagnostic accuracy of clinical decision rules for venous thromboembolism in elderly

BACKGROUND

Physicians committed to the care of elderly patients, are challenged with the diagnosis of venous thromboembolism (VTE: deep venous thrombosis and pulmonary embolism) due to a higher incidence, co-morbidities masking signs and symptoms and burdening referrals. Clinical decision rules (CDRs) have been developed and implemented for VTE. Yet, until now, no study has evaluated the existing evidence of the diagnostic accuracy of CDRs for VTE in elderly.

PURPOSE

To assess the effect of increasing age on diagnostic accuracy of CDRs for VTE in elderly.

DATA SOURCES

A computerized systematic search was performed in Medline and Embase from 1950 to 2010. After checking reference lists and field experts, all key journals were hand searched.

STUDY SELECTION

After review of 1538 eligible citations, nine articles were included and critically appraised on methodological quality by two reviewers using the QUADAS criteria.

DATA EXTRACTION

Data on age subgroups, type of CDRs, sensitivity, specificity, safety, efficiency and the prevalence of deep venous thrombosis (DVT) and pulmonary embolism (PE) were extracted.

DATA SYNTHESIS

Although sensitivity and safety of the CDRs for VTE in elderly remained high, the specificity and efficiency decreased substantially in older age groups.

LIMITATIONS

A limited number of studies met our inclusion criteria. Possible referral bias due to inclusion of relatively high risk elderly patients.

CONCLUSIONS

This diagnostic review demonstrates an increase of prevalence of PE with age and a strong decrease of specificity and efficiency for CDRs of VTE in older patients. Moreover, due to referral bias the decrease in specificity in the elderly may even be underestimated. Although the safety of CDRs for VTE is high, adapting these rules for elderly is much needed to make them more efficient for aged patients.

Diagnosis of venous thromboembolism: an update

Deep vein thrombosis (DVT) and pulmonary embolism (PE) cannot be diagnosed solely on a clinical basis owing to the lack of sensitivity and specificity of clinical signs and symptoms. Phlebography and pulmonary angiography are invasive and resource-demanding imaging modalities. Because the prevalence of DVT and PE is relatively low (typically 20% or less) among clinically suspected individuals, submitting all of them to imaging would not be cost-effective. Therefore, non-invasive diagnostic algorithms have been developed that include clinical probability assessment and D-dimer measurement. These initial steps allow the selection of patients who require non-invasive imaging: compression ultrasonography in cases of suspected DVT and multidetector computed tomography (CT) angiography in cases of suspected PE. This review gives a critical appraisal of the sequential steps of the diagnostic work-up in suspected DVT or PE.

Contemporary management of pulmonary embolism: the answers to ten questions

Pulmonary embolism (PE) cannot be diagnosed solely on a clinical basis, because of the lack of sensitivity and specificity of clinical signs and symptoms. Pulmonary angiography is invasive and resource demanding. Because the prevalence of PE is relatively low (20% or less) amongst individuals who are clinically suspected of having the disease, submitting all of them to imaging (multi-detector CT angiography or ventilation/perfusion lung scintigraphy) would not be cost-effective. Therefore, diagnostic algorithms have been developed that include clinical probability assessment and D-dimer measurement to select the patients who require noninvasive imaging. Once the diagnosis is suspected or confirmed, therapy must be started to avoid potentially fatal recurrence. Treatment starts for an initial 3-month period with a 5-day course of parenteral unfractionated or low-molecular-weight heparin or fondaparinux overlapping with and followed by oral vitamin K antagonists monitored to maintain an international normalized ratio of 2-3. This initial period of 3 months may then be followed by a long-term secondary prevention period in patients who experience an idiopathic thromboembolic event and are at low risk of bleeding. New oral anticoagulants that do require patient monitoring and might exhibit a more favourable benefit-risk balance are currently under extensive clinical testing and might change the situation in the near future. A critical appraisal of the contemporary management of suspected PE is given in this overview with the discussion of 10 practical questions.

[Pulmonary embolism: the extent of computerized tomography]

The use of computerised tomography in the diagnosis of pulmonary embolism has been the subject of clinical research while, at the same time, technical progress has provided the current multidetector-row spiral equipment. Computerised tomography has been assessed both with respect to reference strategies as well as in extensive pragmatic trials. The preliminary evaluation of the clinical probability and the assay of d-dimers has progressively become imperative. The value of the venous doppler ultrasound of the legs, in particular in the elderly, is limited by the variable accessibility according to the centre. In rare cases, uncertainty persists, for example with a good quality negative multidetector-row spiral computerised tomography associated with a high clinical probability, leaving room for complementary explorations. The confrontation between clinicians and radiologists is then all the more pertinent.

Acute respiratory failure in the elderly: diagnosis and prognosis

Acute respiratory failure (ARF) in patients over 65 years is common in emergency departments (EDs) and is one of the key symptoms of congestive heart failure (CHF) and respiratory disorders. Searches were conducted in MEDLINE for published studies in the English language between January 1980 and August 2007, using 'acute dyspnea', 'acute respiratory failure (ARF)', 'heart failure', 'pneumonia', 'pulmonary embolism (PE)' keywords and selecting articles concerning patients aged 65 or over. The age-related structural changes of the respiratory system, their consequences in clinical assessment and the pathophysiology of ARF are reviewed. CHF is the most common cause of ARF in the elderly. Inappropriate diagnosis that is frequent and inappropriate treatments in ED are associated with adverse outcomes. B-type natriuretic peptides (BNPs) help to determine an accurate diagnosis of CHF. We should consider non-invasive ventilation (NIV) in elderly patients hospitalised with CHF or acidotic chronic obstructive pulmonary disease (COPD) who do not improve with medical treatment. Further studies on ARF in elderly patients are warranted.

Diagnosis of pulmonary embolism: in transition

PURPOSE OF REVIEW

To discuss reports published in 2005 on the diagnosis of clinically suspected nonmassive pulmonary embolism.

RECENT FINDINGS

Progress has been made in assessing the clinical probability of pulmonary embolism, in addressing diagnosis in the elderly, in evaluating the diagnostic performance of single-detector and multidetector row helical computed tomography, and in the role of D-dimer measurement and lower limb venous compression ultrasonography in the diagnostic work-up of pulmonary embolism.

SUMMARY

Diagnosing venous thromboembolism depends mainly on noninvasive diagnostic tools that are used sequentially. In most patients, a noninvasive work-up is feasible and the diagnostic algorithms are becoming simpler. This review focuses on developments in clinical probability assessment, pulmonary embolism in the elderly, potential new uses of D-dimer measurement, advent of multidetector row helical computed tomography, and utility of ultrasonography in detecting deep vein thrombosis in patients with suspected pulmonary embolism. With the development of potentially more sensitive diagnostic tests for pulmonary embolism, physicians are now facing the risk of overdiagnosis and hence overtreatment. The issue will no longer be just to detect clots but to identify patients who must be treated using anticoagulants, a complicated question.

Management of venous thromboembolism in the elderly

In this review the authors discuss the use of oral and parenteral anticoagulants for the prevention and treatment of venous thromboembolism (VTE) in the elderly. The use of anticoagulant agents in VTE prophylaxis and treatment in the elderly is complicated by an increase with age in the presence of multiple risk factors and co-morbidities that may increase the risk of both VTE and bleeding. Age itself is identified as an independent risk factor for thromboembolism. VTE is underdiagnosed in the elderly population, and routine prophylaxis frequently falls short of the levels required according to level of risk. Although appropriate anticoagulation of at-risk patients offers a means of reducing the significant VTE burden in this population, concerns have been raised over the use of anticoagulants in a patient group in whom multiple risk factors are common. Bleeding in the elderly can be exacerbated by reduced renal clearance and hypersensitivity to oral anticoagulants that may lead to over-anticoagulation. Although bleeding due to anticoagulant therapy is a serious issue in the elderly, it is often overemphasized, given the therapeutic value otherwise observed in treating this patient group. Warfarin is still used in VTE prophylaxis after orthopaedic surgery and for long-term VTE treatment. Unfractionated and low-molecular-weight heparins (LMWHs) have been shown to be safe and effective in the prophylaxis of VTE, and are now being shown to be as effective as warfarin in the initial and long-term treatment of VTE. LMWHs confer the advantage over unfractionated heparin of subcutaneous once-daily administration with no requirement for laboratory monitoring of their anticoagulant effect, which allows for the convenience of outpatient therapy. New anticoagulants that may be of potential benefit in this patient population include fondaparinux sodium, but clinical experience of this drug in the elderly remains limited.