Assessing clinical probability of pulmonary embolism in the emergency ward: a simple score

Prevalence of pulmonary embolism in acute exacerbations of COPD: a systematic review and metaanalysis

BACKGROUND

Nearly 30% of all exacerbations of COPD do not have a clear etiology. Although pulmonary embolism (PE) can exacerbate respiratory symptoms such as dyspnea and chest pain, and COPD patients are at a high risk for PE due to a variety of factors including limited mobility, inflammation, and comorbidities, the prevalence of PE during exacerbations is uncertain.

METHODS

A systematic review of the literature was performed to determine the reported prevalence of PE in acute exacerbations of COPD in patients who did and did not require hospitalization. The literature search was performed using MEDLINE, CINAHL, and EMBASE, and complemented by hand searches of bibliographies. Only cross-sectional or prospective studies that used CT scanning or pulmonary angiography for PE diagnosis were included.

RESULTS

Of the 2,407 articles identified, 5 met the inclusion criteria (sample size, 550 patients). Overall, the prevalence of PE was 19.9% (95% confidence interval [CI], 6.7 to 33.0%; p = 0.014). In hospitalized patients, the prevalence was higher at 24.7% (95% CI, 17.9 to 31.4%; p = 0.001) than those who were evaluated in the emergency department (3.3%). Presenting symptoms and signs were similar between patients who did and did not have PE.

CONCLUSIONS

One of four COPD patients who require hospitalization for an acute exacerbation may have PE. A diagnosis of PE should be considered in patients with exacerbation severe enough to warrant hospitalization, especially in those with an intermediate-to-high pretest probability of PE.

Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC)

Non-thrombotic PE does not represent a distinct clinical syndrome. It may be due to a variety of embolic materials and result in a wide spectrum of clinical presentations, making the diagnosis difficult. With the exception of severe air and fat embolism, the haemodynamic consequences of non-thrombotic emboli are usually mild. Treatment is mostly supportive but may differ according to the type of embolic material and clinical severity.

Challenges in the diagnosis of acute pulmonary embolism

The state of the art of diagnostic evaluation of hemodynamically stable patients with suspected acute pulmonary embolism was reviewed. Diagnostic evaluation should begin with clinical assessment using a validated prediction rule in combination with measurement of D-dimer when appropriate. Imaging should follow only when necessary. Although with 4-slice computed tomography (CT) and 16-slice CT, the sensitivity for detection of pulmonary embolism was increased by combining CT angiography with CT venography, it is not known whether CT venography increases the sensitivity of 64-slice CT angiography. Methods to reduce the radiation exposure of CT venography include imaging only the proximal leg veins (excluding the pelvis) and obtaining discontinuous images. Compression ultrasound can be used instead. In young women, radiation of the breasts produces the greatest risk of radiation-induced cancer. It may be that scintigraphy is the imaging test of choice in such patients, but this pathway should be tested prospectively. A patient-specific approach to the diagnosis of pulmonary embolism can be taken safely in hemodynamically stable patients to increase efficiency and decrease cost and exposure to radiation.

D-Dimer for venous thromboembolism diagnosis: 20 years later

Twenty years after its first use in the diagnostic workup of suspected venous thromboembolism (VTE), fibrin D-dimer (DD) testing has gained wide acceptance for ruling out this disease. The test is particularly useful in the outpatient population referred to the emergency department because of suspected deep vein thrombosis (DVT) or pulmonary embolism (PE), in which the ruling out capacity concerns every third patient clinically suspected of having the disease. This usefulness is based on the high sensitivity of the test to the presence of VTE, at least for some assays. Due to its poor specificity precluding its use for ruling in VTE, DD testing must be integrated in comprehensive, sequential diagnostic strategies that include clinical probability assessment and imaging techniques such as lower limb venous compression ultrasonography for suspected DVT or multi-slice helical computed tomography for suspected PE. The present narrative review updates the data available on the use of the various commercially available DD assays in the diagnostic approach of clinically suspected VTE in distinct patient populations or situations, including outpatients and inpatients, patients with cancer, older age, pregnancy, a suspected recurrent event, limited thrombus burden, and patients already on anticoagulant treatment.

Troponin I and right ventricular dysfunction for risk assessment in patients with nonmassive pulmonary embolism in the Emergency Department in combination with clinically based risk score

To determine whether troponin I (cTnI) and right ventricular (RV) dysfunction predict adverse in-hospital outcomes in patients admitted to the Emergency Department (ED) with definite nonmassive pulmonary embolism (PE) independent of and in addition to a recently validated clinical prognostic risk score. From a pool of 168 patients with suspected PE, 89 had nonmassive PE confirmed by spiral lung angio-computed tomography. By the clinical prognostic score, in our study sample, 14% had very low risk; 17% had low risk, 20% had intermediate risk, whereas high risk and very high risk were identified in 29 and 20%, respectively. Prevalence of elevated cTnI (>0.1 microg/L, 57%) at admission was comparable among patients grouped by clinical prognostic score (P = NS); echocardiographic RV dysfunction (54%) was more prevalent with intermediate or high clinical risk score (P < 0.02). Increased cTnI predicted primary end-point (development of hemodynamic instability, overall 33 cases, 37%) independent of and in addition to the clinical risk class and RV dysfunction (P < 0.01 for interaction). Fatal events (12 cases, 14%, 5 definite, 7 possible PE-related) were predicted by higher clinical risk score (P < 0.05). In patients with nonmassive central PE admitted to the ED, increased cTnI contributed to identifying those with increased risk of development of hemodynamic instability independent of and in addition to a validated clinically based risk score.

Transthoracic echocardiography for suspected pulmonary embolism in the intensive care unit: unjustly underused or rightfully ignored?

Transthoracic echocardiography (TTE) is an established part of modern medical practice, and its use in documenting cardiac disorders has long been recognized. Since the introduction of 2-dimensional TTE, the right-sided heart chambers have become amenable to fairly accurate analysis, enabling the evaluation of morphologic and functional abnormalities associated with many cardiopulmonary diseases, including pulmonary embolism (PE). The availability of small, portable echocardiographic units combined with an increasing number of intensive care specialists trained in echocardiography makes TTE an attractive modality for the diagnosis of PE in the intensive care unit (ICU). In the ICU setting, prompt decision-making and appropriate triage of critically ill patients can facilitate early institution of therapy for PE while awaiting patient stabilization and further definitive testing. Although several prior reviews incorporate TTE in the overall approach and clinical decision algorithms pertaining to the diagnosis and treatment of pulmonary embolism, no dedicated review exists that focuses purely on TTE. We attempt to fill that gap by reviewing the available literature pertaining to use of TTE in the diagnosis of suspected PE, and by better defining the use of TTE in the ICU setting. Emphasis is placed on the use of TTE as a clinical triage tool for suspected PE.

The value of ischemia-modified albumin compared with d-dimer in the diagnosis of pulmonary embolism

Study objective

The primary aim of this study was to investigate whether IMA levels are helpful in the diagnosis of pulmonary embolism (PE). The secondary aim was to determine whether IMA was more effective alone or in combination with clinical probability scores in the diagnosis of PE. Thirdly, the sensitivity and specificity of IMA is compared with D-dimer both with and without clinical probability scores in patients with suspected PE.

Methods

Consecutive patients presenting to the emergency department with suspected PE were prospectively recruited, and healthy volunteers were also enrolled as controls. D-dimer and IMA levels were measured for the entire study group. Wells and Geneva scores were calculated and s-CTPA was performed on all suspected PE patients.

Results

The study population consisted of 130 patients with suspected PE and 59 healthy controls. Mean IMA levels were 0.362 ± 0.11 ABSU for Group A, the PE group (n = 75); 0.265 ± 0.07 ABSU for Group B, the non-PE group (n = 55); and 0.175 ± 0.05 ABSU for Group C, the healthy control group (p < 0.0001). At a cut-off point of 0.25 ABSU, IMA was 93% sensitive and 75% specific in the diagnosis of PE. PPV was 79.4% and NPV was 78.6%. Mean D-dimer levels were 12.48 ± 10.88 μg/ml for Group A; 5.36 ± 7.80 μg/ml for Group B and 0.36 ± 0.16 μg/ml for Group C (p < 0.0001). The D-dimer cut-off point was 0.81 μg/ml with a sensitivity of 98.9% and a specificity of 62.7%, PPV of 69.4% and NPV of 83.3%. The use of IMA in combination with Wells and Geneva clinical probability scores was determined to have a positive impact on these scores' sensitivity and negative predictive values.

Conclusion

IMA is a good alternative to D-dimer in PE diagnosis in terms of both cost and efficiency. Used in combination with clinical probability scores, it has a similar positive effect on NPV and sensitivity to that of D-dimer. The PPV of IMA is better than D-dimer, but it is still unable to confirm a diagnosis of PE without additional investigation.

Pulmonary embolism despite negative ELISA D-dimer: a case report

Pulmonary embolus (PE) can be fatal, but is often treatable if recognized early. Unfortunately, the clinical presentation of PE is often variable and misleading. The D-dimer assay has recently come into favor as a method to exclude PE; however, this test has an acceptable safety margin only in low-risk populations. What is unclear is the exact composition of this low risk population. This is the report of a 26-year-old woman with over 2 weeks of chest pain and intermittent dyspnea. The patient was initially seen in the Emergency Department (ED) and hospitalized. She returned to the ED 2 weeks later with similar symptoms. Although enzyme-linked immunosorbent assay (ELISA) D-dimer assays were normal on the initial and subsequent ED visits, pulmonary embolism (PE) was diagnosed by computed tomography scan on the second visit. This report highlights the risk of misdiagnosing PE if relying solely on ELISA D-dimer for exclusion. The approach to PE should include a measure of clinical probability. This report documents the presentation of PE despite having two unremarkable ELISA D-dimer measurements, and highlights the importance of clinical suspicion.

Computerised tomography for the detection of pulmonary emboli in intensive care patients--a retrospective cohort study

Pulmonary emboli are frequently considered as a cause for respiratory deterioration in intensive care unit (ICU) patients, however empirical observation suggests that computerised tomographic (CT) angiography is infrequently positive after the first 24 hours. This study aimed to determine the rate and risk factors for detection of pulmonary emboli by CT angiography in ICU patients. All patients undergoing CT angiography > 24 hours after ICU admission for respiratory deterioration from April 2000 until January 2004 were included. The positivity rate for pulmonary emboli was determined and risk factors analysed. Seven (6%) out of 113 CT angiograms were positive for pulmonary emboli. All were found in trauma patients. Comparing positive to negative scans, predefined risk factors including head injury (5/7 positive scans, 71% vs. 23/106 negative scans, 22%, P = 0.005), spine injury with neurological impairment (4/7, 57% vs. 9/106, 8%, P = 0.002) and lower limb injury (3/7, 43% vs. 12/106, 9%, P = 0.039) were significantly more frequent in patients with positive scans. Deep vein thrombosis prophylaxis was employed less frequently prior to a positive scan (in 3/7, 43% patients with positive scans vs. 91/106, 86% patients with negative scans P = 0.015). Only the predefined risk factors were independently associated with positive CT angiography on limited logistic regression (OR 24.7 per risk factor, 95% CI 2.38 to 255.1, P = 0.007). Pulmonary emboli were infrequently diagnosed using CT angiography in ICU patients admitted for more than 24 hours and found only in patients with recognised risk factors.

Advances in the detection of pulmonary embolism

BACKGROUND

Diagnosing or excluding pulmonary embolism is a complex challenge. Many diagnostic instruments can be used in patients with clinically suspected pulmonary embolism nowadays, all with their own (dis-)advantages. Methods/objectives: In this review, these (dis-)advantages are discussed for the following diagnostic instruments: clinical probability assessment, D-dimer concentration, the combination of clinical probability assessment and D-dimer concentration, bilateral compression ultrasonography, ventilation/perfusion scintigraphy, computerized tomographic pulmonary angiography, pulmonary angiography and magnetic resonance pulmonary angiography. A diagnostic strategy, which can be adjusted to local facilities, is provided and discussed.

CONCLUSION

Using combinations of some of these diagnostic tools, many diagnostic strategies are possible and every hospital should make its own local protocol suited for the local situation.

Pretest risk assessment in suspected acute pulmonary embolism

RATIONALE AND OBJECTIVES

To assess the pretest practices of US clinicians who treat patients with acute pulmonary embolism (PE).

MATERIALS AND METHODS

We surveyed 855 practicing physicians selected randomly from three professional organizations. We asked participants to estimate how often and by what method they determine the likelihood of PE before they request confirmatory studies. Participants reported their awareness of four published clinical practice guidelines dealing with acute PE and selected options for further diagnostic testing after reviewing clinical data from three hypothetical patients presenting with low, intermediate, and high probability of acute PE.

RESULTS

We received completed surveys from 240 physicians practicing in 44 states. Although most (98.3%) report that they assess pretest probability of PE before testing, slightly more than half do so routinely. A total of 72.5% prefer an unstructured approach to pretest assessment, whereas 22.9% use published prediction rules. Most (93.0%) are aware of at least one published guideline for assessing acute PE, but only 44.2% report using one or more in daily practice. Respondents who use published prediction rules, estimate pretest probability routinely, or use at least one practice guideline were more likely to request additional testing when reviewing a low probability clinical scenario. No differences in testing frequency or preferences were observed for intermediate or high probability clinical scenarios.

CONCLUSIONS

The majority of clinicians we surveyed use an unstructured approach when estimating the pretest probability of acute PE. With the exception of low probability scenario, clinicians agreed on testing choices in suspected acute PE, regardless of the method or frequency of pre-test assessment.

Comparison of the revised Geneva score with the Wells rule for assessing clinical probability of pulmonary embolism

BACKGROUND

The revised Geneva score, a standardized clinical decision rule in the diagnosis of pulmonary embolism (PE), was recently developed. The Wells clinical decision is widely used but lacks full standardization, as it includes subjective clinician's judgement. We have compared the performance of the revised Geneva score with the Wells rule, and their usefulness for ruling out PE in combination with D-dimer measurement.

METHODS

In 300 consecutive patients, the clinical probability of PE was assessed prospectively by the Wells rule and retrospectively using the revised Geneva score. Patients comprised a random sample from a single center, participating in a large prospective multicenter diagnostic study. The predictive accuracy of both scores was compared by area under the curve (AUC) of receiver operating characteristic (ROC) curves.

RESULTS

The overall prevalence of PE was 16%. The prevalence of PE in the low-probability, intermediate-probability and high-probability categories as classified by the revised Geneva score was similar to that of the original derivation set. The performance of the revised Geneva score as measured by the AUC in a ROC analysis did not differ statistically from the Wells rule. After 3 months of follow-up, no patient classified into the low or intermediate clinical probability category by the revised Geneva score and a normal D-dimer result was subsequently diagnosed with acute venous thromboembolism.

CONCLUSIONS

This study suggests that the performance of the revised Geneva score is equivalent to that of the Wells rule. In addition, it seems safe to exclude PE in patients by the combination of a low or intermediate clinical probability by the revised Geneva score and a normal D-dimer level. Prospective clinical outcome studies are needed to confirm this latter finding.

Vena cava inferior thrombosis detected by venous hum: a case report

We describe a patient in which a venous hum, heard during abdominal auscultation, lead to the diagnosis of a vena cava inferior thrombosis.

Clinical characteristics of patients with acute pulmonary embolism: data from PIOPED II

BACKGROUND

Selection of patients for diagnostic tests for acute pulmonary embolism requires recognition of the possibility of pulmonary embolism on the basis of the clinical characteristics. Patients in the Prospective Investigation of Pulmonary Embolism Diagnosis II had a broad spectrum of severity, which permits an evaluation of the subtle characteristics of mild pulmonary embolism and the characteristics of severe pulmonary embolism.

METHODS

Data are from the national collaborative study, Prospective Investigation of Pulmonary Embolism Diagnosis II.

RESULTS

There may be dyspnea only on exertion. The onset of dyspnea is usually, but not always, rapid. Orthopnea may occur. In patients with pulmonary embolism in the main or lobar pulmonary arteries, dyspnea or tachypnea occurred in 92%, but the largest pulmonary embolism was in the segmental pulmonary arteries in only 65%. In general, signs and symptoms were similar in elderly and younger patients, but dyspnea or tachypnea was less frequent in elderly patients with no previous cardiopulmonary disease. Dyspnea may be absent even in patients with circulatory collapse. Patients with a low-probability objective clinical assessment sometimes had pulmonary embolism, even in proximal vessels.

CONCLUSION

Symptoms may be mild, and generally recognized symptoms may be absent, particularly in patients with pulmonary embolism only in the segmental pulmonary branches, but they may be absent even with severe pulmonary embolism. A high or intermediate-probability objective clinical assessment suggests the need for diagnostic studies, but a low-probability objective clinical assessment does not exclude the diagnosis. Maintenance of a high level of suspicion is critical.

Newer modalities for detection of pulmonary emboli

Pulmonary embolism (PE) is the third most common cardiovascular disease after myocardial infarction and stroke in the United States. Early and accurate diagnosis of this condition is imperative because many patients die within hours of presentation. Clinical and laboratory tests can be used to accurately determine the pretest probability of PE. When necessary, imaging techniques are then used to exclude or diagnose PE. Pulmonary angiography is the reference standard for the diagnosis of PE, but it is invasive and has a high morbidity and mortality rate. Ventilation and perfusion (V/Q) scanning in the past has been recommended as the initial diagnostic test for PE; however, this technique also has limitations. Recently, new modalities for the diagnosis and exclusion of PE have been evaluated. These techniques include V/Q single photon emission computed tomography (SPECT), single- and multi-detected computed tomography, and magnetic resonance angiography (MRA) including gadolinium-enhanced MRA, real-time magnetic resonance imaging (RT-MR), and magnetic resonance perfusion imaging.

Transthoracic echocardiography for pulmonary embolism in the ICU: finding the "right" findings

BACKGROUND

Use of transthoracic echocardiography (TTE) in documenting cardiac disorders is well accepted. This study reviews institutional experience with TTE in the clinical setting of pulmonary embolism (PE).

STUDY DESIGN

Retrospective review of surgical ICU patients who underwent TTE within 72 hours of diagnosis of PE, from January 2005 to March 2007. Collected data included symptoms, clinical suspicion of PE, preexisting conditions, operative procedures, TTE findings, presence of deep venous thrombosis, and treatments used for PE. Preexisting TTEs, when available, were compared with those obtained after acute PE. TTEs subsequent to the first post-PE study were analyzed for change in severity of findings.

RESULTS

Thirty-one patients (12 men, 19 women, mean age 66 years, APACHE II 18.1) were included. Twenty-two had high, and nine had moderate, clinical suspicion for PE. Radiographic diagnosis of PE was made by computed tomography (25 of 31) and by ventilation-perfusion scans (6 of 31). Twelve of 31 patients had extremity deep venous thrombosis by duplex ultrasonography. Tricuspid regurgitation was the most common TTE finding (28 of 31), followed by pulmonary hypertension (24), dilated right ventricle (23), right heart strain (19), and underfilled, hyperdynamic left ventricle (17). Seventeen patients had previous or "baseline" echocardiograms, and when compared with the post-PE TTE, all patients demonstrated worsening in at least one TTE finding.

CONCLUSIONS

This study identified findings that can be used in prospective evaluation of TTE for suspected PE. The importance of baseline TTE has also been emphasized. Additional prospective evaluation of TTE in diagnosis of suspected PE in the ICU is warranted.

A prospective reassessment of the utility of the Wells score in identifying pulmonary embolism

OBJECTIVE

To assess whether a cumulative clinical risk score (Wells score) can optimise imaging strategies in patients with suspected pulmonary embolism (PE).

DESIGN, SETTING AND PARTICIPANTS

Prospective, consecutive series of 633 studies on 595 patients referred to a major teaching hospital for ventilation/perfusion (V/Q) scanning for suspected acute PE between September 2004 and November 2005. Ventilation scintigraphy was performed using technetium-99m Technegas, and V/Q results were interpreted in conjunction with Wells scores.

MAIN OUTCOME MEASURES

Likelihood of PE for each Wells score interval; overall prevalence of PE.

RESULTS

The likelihood of PE for a given Wells score in our study was not significantly different from the likelihood in the original study by Wells et al. Scores of < 2 in our study were associated with a 4% risk of PE, scores between 2 and 6 with a 13% risk, and scores > 6 with a 67% risk. The overall prevalence of PE in our study was significantly less than that in the original study (9% v 16%; P < 0.01), attributable to a significantly larger proportion of our patients having scores of < 2 (66% v 40%; P < 0.0001).

CONCLUSION

The Wells score remains a robust clinical tool for stratifying the likelihood of PE. Patients with Wells scores of > 2 warrant imaging assessment for PE, but for those with scores < 2, further imaging may be problematic.

Influence of age on the cost-effectiveness of diagnostic strategies for suspected pulmonary embolism

BACKGROUND

Age has a marked effect on the diagnostic yield of D-dimer measurement and lower limb compression ultrasonography (CUS) in patients with suspected pulmonary embolism (PE), suggesting that specific diagnostic strategies may be needed in elderly patients.

OBJECTIVE

To evaluate the cost-effectiveness of including D-dimer and CUS in the workup of PE, with particular attention to patient age.

SUBJECTS AND METHODS

We analyzed data from two recent outcome studies that enrolled 1721 consecutive outpatients with suspected PE. Both studies used a sequential diagnostic strategy that included assessment of clinical probability, D-dimer measurement, CUS, and helical computed tomography (hCT). A decision analysis model was created for analyzing cost-effectiveness according to six classes of age. The main outcome measures were 3-month quality-adjusted expected survival and costs per patient managed.

RESULTS

All strategies were equally safe, with variations in the 3-month survival never exceeding 0.5% as compared to the most effective strategy. D-dimer measurement was highly cost-saving under the age of 80 years. Above 80 years, the cost-sparing effect of D-dimer was diminished, but not completely abolished. Inclusion of CUS increased the costs of diagnostic strategies irrespective of age. Results were unchanged over a wide range of the variables of interest (costs, sensitivity, and specificity of the tests).

CONCLUSIONS

Diagnostic strategies using D-dimer are less expensive. The cost-sparing effect of D-dimer is reduced but not abolished above 80 years, suggesting that adapting specific diagnostic strategies in elderly outpatients is not mandatory. CUS is costly, and only marginally improves the safety of diagnostic strategies for PE.

Integrated strategies for the diagnosis of venous thromboembolism

Diagnosis of deep vein thrombosis (DVT) and pulmonary embolism (PE) is an important medical problem because of the high fatality rate from PE and the large number of cases not diagnosed before causing death. Over the last decade, there has been considerable research into the diagnostic process. It is widely accepted that venous ultrasound imaging is an accurate test for the diagnosis of DVT and is the imaging test of choice. For PE, computer tomographic pulmonary angiography (CTPA) is replacing ventilation perfusion lung scanning. Technology for CTPA is rapidly evolving and multi-row detector scans have quite reasonable sensitivity and specificity. Despite the accuracy of imaging tests, the post-test probability of disease is highly dependent on pretest probability. Clinical evaluation tools have developed that enable us to accurately categorize patients' risk prior to diagnostic imaging. One advantage of this characterization is an ability to exclude the diagnosis of DVT or PE if clinical probability is sufficiently low and when the D-dimer is negative. There are now a number of D-dimer assays that have well-defined specificities and sensitivities, which enable use in conjunction with clinical probability. A careful combination of clinical assessment, D-dimer and imaging enables safe PE rule out protocols without imaging, an ability to suspect false positive imaging results, and more accurate determination of true positive imaging. These integration strategies result in safer, more convenient and cost-effective care for patients.

Examination of hospital referral practices for CT pulmonary angiography

Guidelines for the evaluation of venous thromboembolism (VTE) include a history and physical examination in conjunction with computed tomographic pulmonary angiography (CTPA), Doppler ultrasonography, and D-dimer measurements. We performed a retrospective analysis to evaluate the diagnostic yield of CTPA at our facility. Patients between the ages of 18 and 100 with a CTPA completed through the emergency department and/or any inpatient service over a 6-month period were reviewed and a retrospective Simplified Wells Score was calculated. Three hundred and three patients underwent CTPA for acute VTE. A Simplified Wells Score was calculated for 279 subjects, with a mean score of 1.6 +/- 1.6. Twenty CTPA procedures demonstrated VTE, a positive rate of 7.2%, which was lower than expected. This result likely reflects lack of adherence to a clinical algorithm for assessment of VTE and an overly cautious approach to symptom evaluation.

Evaluation of the Elderly Patient with Acute Chest Pain

Chest pain is one of the most common and serious chief complaints. Geriatricians must be well versed in evaluating elderly patients who have chest pain. This article discusses the initial diagnostic evaluation of elderly patients with chest pain. Specific emphasis is placed on identifying acute coronary syndromes, aortic dissection, pulmonary embolism, and pericarditis with cardiac tamponade. By understanding the different presentations of these potentially life-threatening emergencies, the geriatrician will be better prepared to distinguish them from less dire conditions and to initiate prompt treatment.

Can multislice CT alone rule out reliably pulmonary embolism? A prospective study

PURPOSE

To evaluate the safety of withholding anticoagulation in patients with suspected acute pulmonary embolism after negative multislice computed tomography (MSCT) pulmonary angiography and lower-limb venography.

MATERIALS AND METHODS

A total of 383 consecutive patients with suspected acute pulmonary embolism were prospectively studied. Patients underwent MSCT pulmonary angiography and lower-limb venography, as well as pulmonary scintigraphy and lower-limb ultrasound examination. Patients with negative MSCT results for both pulmonary embolism and venous thrombosis were not administered anticoagulants and were followed up for 6 months to rule out thromboembolism.

RESULTS

At MSCT, 156 patients were positive for pulmonary embolism, venous thrombosis, or both; 224 were negative; and findings were inconclusive in three. False-negatives were five patients with high probability scintigram and two with venous thrombosis detected at US. A total of 184 patients with negative MSCT and without anticoagulation were followed up for 6 months. During this period of time just one recurrence of pulmonary embolism was detected. The negative predictive value of MSCT pulmonary angiography plus lower-limb venography was 95.8% (183/191).

CONCLUSION

MSCT is efficacious in diagnosing pulmonary embolism, with negative predictive values reported in the literature ranging from 94% to 100%. This enables omission of anticoagulation in patients with suspected pulmonary embolism after negative MSCT findings without the need for other diagnostic tests.

Pulmonary embolism risk assessment screening tools: the interrater reliability of their criteria

BACKGROUND

Diagnostic evaluation for suspected pulmonary embolism (PE) is challenging. Dimerized plasmin fragment D (D-dimer) assays are increasingly used but have been validated only in "low-risk" patients. The accurate interpretation and application of risk assessment criteria are critical to the appropriate use of D-dimer. We sought to determine the interrater agreement of attending and third-year resident emergency medicine physicians in the specific elements of the Canadian and the Charlotte risk stratification tools and their clinical application.

METHODS

We prospectively enrolled a convenience sample of patients presenting to an urban university emergency department with suspected PE. Standardized data collection sheets were used by an attending physician and a third-year resident physician to determine the presence or absence of risk factors included in published PE prediction instruments. Each physician was blinded to the other's results and the patients' D-dimer result. Interrater agreement was measured using kappa statistics (with 95% confidence intervals).

RESULTS

Two hundred seventy-one patients were screened. The kappa scores for each risk criterion were as follows: previous deep vein thrombosis, 0.90 (95% confidence interval, 0.83-0.97); malignancy, 0.87 (0.76-0.97); deep vein thrombosis symptoms, 0.54 (0.39-0.70); immobilization, 0.41 (0.26-0.57); unexplained hypoxia, 0.58 (0.42-0.74); tachycardia, 0.94 (0.89-0.98); hemoptysis, 0.76 (0.51-1.0); and PE more likely than another diagnosis, 0.50 (0.36-0.64).

CONCLUSIONS

Interrater agreement was only fair for several important risk criteria. Small differences in determining pretest probability can lead to significant variability in risk assessment and how, or whether, the diagnosis of PE is evaluated. This study raises questions about the reliability and applicability of published PE screening criteria in clinical settings.

Increased troponin I predicts in-hospital occurrence of hemodynamic instability in patients with sub-massive or non-massive pulmonary embolism independent to clinical, echocardiographic and laboratory information

INTRODUCTION

Whether in patients with acute central sub-massive or non-massive pulmonary embolism, mild troponin I increase (>0.03 mug/L) predicts in-hospital occurrence of hemodynamic instability and death independent to prognostically relevant clinical, laboratory and echocardiographic information is not fully established.

METHODS AND RESULTS

We evaluated consecutively patients admitted to the Emergency Room for pulmonary embolism; those in stable hemodynamics in whom central pulmonary embolism was confirmed by spiral-computed tomography were recruited. All participants underwent standardized study protocol, including clinical and diagnostic evaluation for assessment of severity of pulmonary embolism; therapy was established accordingly; troponin I was measured, but treatment protocol was not affected by knowledge of troponin I levels. Of 90 patients enrolled in the study, 33 (37%) developed hemodynamic instability during hospitalization (on average, 90 h +/-20 from admission). Troponin I was >0.03 microg/L in 56% of the study population at admission, and predicted occurrence of hemodynamic instability during hospitalization (adjusted hazard ratio 9.8, 95% confidence interval 1.2-79.2), independent to age, gender, co-morbidity, systolic blood pressure, CK-MB, echocardiographic right ventricular dysfunction and other covariates. Twelve patients died during hospitalization (mean time to event 107 h +/-24 from admission); troponin I >0.03 microg/L predicted mortality in univariate analysis, but not after accounting for age, sex and clinical variables. Nevertheless, higher troponin as continuous variable correlated with higher likelihood of in-hospital death (adjusted likelihood ratio 2.2/microg/L, 95% confidence interval 1.1-4.3) in multivariate analysis. In a further multivariate model, CK-MB predicted mortality independent of covariates and troponin I.

CONCLUSIONS

In patients with acute central sub-massive or non-massive pulmonary embolism, even mild increase in troponin I >0.03 microg/L may provide relevant short-term prognostic information independent to clinical, laboratory and echocardiographic data.

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.

Emergency medicine practitioner knowledge and use of decision rules for the evaluation of patients with suspected pulmonary embolism: variations by practice setting and training level

BACKGROUND

Several clinical decision rules (CDRs) have been validated for pretest probability assessment of pulmonary embolism (PE), but the authors are unaware of any data quantifying and characterizing their use in emergency departments.

OBJECTIVES

To characterize clinicians' knowledge of and attitudes toward two commonly used CDRs for PE.

METHODS

By using a modified Delphi approach, the authors developed a two-page paper survey including 15 multiple-choice questions. The questions were designed to determine the respondents' familiarity, frequency of use, and comprehension of the Canadian and Charlotte rules. The survey also queried the frequency of use of unstructured (gestalt) pretest probability assessment and reasons why physicians choose not to use decision rules. The surveys were sent to physicians, physician assistants, and medical students at 32 academic and community hospitals in the United States and the United Kingdom.

RESULTS

Respondents included 555 clinicians; 443 (80%) work in academic practice, and 112 (20%) are community based. Significantly more academic practitioners (73%) than community practitioners (49%) indicated familiarity with at least one of the two decision rules. Among all respondents familiar with a rule, 50% reported using it in more than half of applicable cases. A significant number of these respondents could not correctly identify a key component of the rule (23% for the Charlotte rule and 43% for the Canadian rule). Fifty-seven percent of all respondents indicated use of gestalt rather than a decision rule in more than half of cases.

CONCLUSIONS

Academic clinicians were more likely to report familiarity with either of these two specific decision rules. Only one half of all clinicians reporting familiarity with the rules use them in more than 50% of applicable cases. Spontaneous recall of the specific elements of the rules was low to moderate. Future work should consider clinical gestalt in the evaluation of patients with possible PE.

Diagnostic pathways in acute pulmonary embolism: recommendations of the PIOPED II investigators

PURPOSE

To formulate comprehensive recommendations for the diagnostic approach to patients with suspected pulmonary embolism, based on randomized trials.

METHODS

Diagnostic management recommendations were formulated based on results of the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II) and outcome studies.

RESULTS

The PIOPED II investigators recommend stratification of all patients with suspected pulmonary embolism according to an objective clinical probability assessment. D-dimer should be measured by the quantitative rapid enzyme-linked immunosorbent assay (ELISA), and the combination of a negative D-dimer with a low or moderate clinical probability can safely exclude pulmonary embolism in many patients. If pulmonary embolism is not excluded, contrast-enhanced computed tomographic pulmonary angiography (CT angiography) in combination with venous phase imaging (CT venography), is recommended by most PIOPED II investigators, although CT angiography plus clinical assessment is an option. In pregnant women, ventilation/perfusion scans are recommended by many as the first imaging test following D-dimer and perhaps venous ultrasound. In patients with discordant findings of clinical assessment and CT angiograms or CT angiogram/CT venogram, further evaluation may be necessary.

CONCLUSION

The sequence for diagnostic test in patients with suspected pulmonary embolism depends on the clinical circumstances.