Clinical policy: critical issues in the evaluation and management of adult patients presenting with suspected lower-extremity deep venous thrombosis

Deep Venous Thrombosis

Deep venous thrombosis (DVT) is a frequently encountered condition that is often diagnosed and treated in the outpatient setting. Risk stratification is helpful and recommended in the evaluation of DVT. An evidence-based diagnostic approach is discussed here. Once diagnosed, the mainstay of DVT treatment is anticoagulation. The specific type and duration of anticoagulation depend upon the suspected etiology of the venous thromboembolism, as well as risks of bleeding and other patient comorbidities. Both specific details and a standardized approach to this vast treatment landscape are presented.

Holistic ultrasound in trauma: An update

Holistic ultrasound is a total body examination using an ultrasound device aiming to achieve immediate patient care and decision making. In the setting of trauma, it is one of the most fundamental components of care of the injured patients. Ground-breaking imaging software allows physicians to examine various organs thoroughly, recognize imaging signs early, and potentially foresee the onset or the possible outcome of certain types of injuries. Holistic ultrasound can be performed on a routine basis at the bedside of the patients, at admission and during the perioperative period. Trauma care physicians should be aware of the diagnostic and guidance benefits of ultrasound and should receive appropriate training for the optimal management of their patients. In this paper, the findings of holistic ultrasound in trauma patients are presented, with emphasis on the lungs, heart, cerebral circulation, abdomen, and airway. Additionally, the benefits of ultrasound imaging in interventional anaesthesia techniques such as ultrasound-guided peripheral nerve blocks and central vein catheterization are described.

Risk stratification using D-dimers in patients presenting to the emergency department with nonspecific complaints

BACKGROUND

Patients with nonspecific complaints (NSC) such as generalized weakness present frequently to acute care settings. These patients are at risk of adverse health outcomes. The aim of our study was to test the hypothesis whether D-dimers are predictive for 30-day mortality in patients with NSCs.

METHODS

Delayed type cross-sectional diagnostic study with a 30-day follow-up period, registered with ClinicalTrials.gov (NCT00920491). This study took place in 2 EDs in Northwestern Switzerland. Patients were enrolled in the study if they were over 18years of age, gave informed consent, and if they presented with NSCs such as generalized weakness. D-dimer levels were determined at ED presentation.

RESULTS

The final study population consisted of 524 patients. Median age was 82years (IQR=75 to 87years); 40.5% were men. There were 489 survivors and 35 non-survivors at 30-day follow-up. Twenty-one (60%) of the non-survivors were males. D-dimer levels were significantly higher in non-survivors than in survivors (p<0.001). Univariate Cox regression models for D-dimer resulted in a C-index of 0.77 for prediction of mortality. A model including sex, age, Katz ADL and D-dimer in a multivariate Cox regression lead to a C-Index of 0.80.

CONCLUSION

D-dimer testing might be an effective risk stratification tool in patients with NSC by helping to identify patients at low risk of short-term mortality with a sensitivity of 0.97 and a negative likelihood ratio of 0.121. The use of D-dimers for risk stratification in patients with NSC should be confirmed with prospective studies.

Fatal pulmonary embolization after negative serial ultrasounds

BACKGROUND

Isolated distal deep vein thrombosis (DVT) is not traditionally viewed as a potentially life-threatening condition. There are conflicting recommendations regarding its evaluation and treatment, and wide variability in clinical practice. The presentation of this case highlights the fatal potential of this condition.

CASE REPORT

This is the report of a previously healthy young woman who presented to the emergency department with calf pain concerning for a DVT. She received two radiologist-performed duplex ultrasound examinations of the affected extremity, both of which were negative, but suffered a sudden cardiac arrest several hours after the second study. Autopsy attributed the death to DVT and pulmonary embolism. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the risk for fatal pulmonary embolization, even after normal serial ultrasound examinations to exclude DVT.

The dynamics of D-dimer level fluctuation in patients after the cemented and cementless total hip and total knee replacement

INTRODUCTION

The number of total hip and total knee replacement procedures performed worldwide has tended to surge in recent years, due to the combination of such factors as the increased life expectancy, improved quality of life, advances in medical technology as well as pre-operative and post-operative patient management.Numerous studies confirm that patients undergoing major orthopaedics procedures involving lower extremities, for instance total hip and total knee replacement, constitute the highest risk group for the development of post-operative venous thromboembolism (VTE), primarily manifested as deep vein thrombosis (DVT).

PURPOSE

The purpose of the research was to assess the dynamics of D-dimer level fluctuation during the post-operative period in patients after the cemented or cementless total hip replacement (THR) or total knee replacement (TKR), in order to prove or reject the thesis that the cemented and cementless THR or TKR affects the post-operative D-dimer levels.

MATERIAL AND METHODS

The study group consisted of 47 patients aged 29-82 years. Of them, 23 had the cementless THR, 12 subjects had the cemented THR and another 12 patients had the TKR. All of the patients performed to measure the concentration of D-dimers in the peri-operative period at predetermined time points. For the peri-operative period was adopted from time 1 day before surgery to 10-day hospitalization. The subarachnoid block (SAB) was performed in all patients.

RESULTS

The distribution of D-dimer values throughout the entire post-operative period (up to 10th post-operative day) followed the sinusoid pattern with two peaks in all patients. It was not specific in any group.

CONCLUSIONS

1. The D-dimer level almost doubles during the post-operative period in patients after THR or TKR.2. Higher level of D-dimers in post-operative period in the research group of patients does not relate to higher risk of thromboembolic disease.

Comparative study on the effectiveness of myofascial release manual therapy and physical therapy for venous insufficiency in postmenopausal women

OBJECTIVES

Venous insufficiency is present in a large number of postmenopausal women, increasing their risk of disability. The objective of this study was to determine the effects of myofascial release therapy and conventional kinesiotherapy on venous blood circulation, pain and quality of life in postmenopausal patients with venous insufficiency.

METHODS

A randomised controlled trial was undertaken. We enrolled 65 postmenopausal women with stage I or II venous insufficiency on the clinical, aetiological, anatomical and physiopathological (CEAP) scale of venous disorders, randomly assigning them to a control (n=32) or experimental (n=33) group. The control and experimental group patients underwent physical venous return therapy (kinesiotherapy) for a 10-week period, during which the experimental group patients also received 20 sessions of myofascial release therapy. Main outcome measures determined pre- and post-intervention were blood pressure, cell mass, intracellular water, basal metabolism, venous velocity, skin temperature, pain and quality of life.

RESULTS

Basal metabolism (P<0.047), intracellular water (P<0.041), diastolic blood pressure (P<0.046), venous blood flow velocity (P<0.048), pain (P<0.039) and emotional role (P<0.047) were significantly higher in the experimental group than in the control group after the 10-week treatment programme.

CONCLUSION

The combination of myofascial release therapy and kinesiotherapy improves the venous return blood flow, pain and quality of life in postmenopausal women with venous insufficiency.

Fibrinolysis and thrombectomy for massive pulmonary embolus

Treatment options for massive and submassive pulmonary embolus may include hemodynamic support, fibrinolysis, anticoagulation, and thrombectomy. Selection of the appropriate therapy requires scrutiny of the patient's hemodynamic status, preexisting conditions, risk of complications, and availability of services at the treatment center. This article illustrates a case of successful fibrinolysis and thrombectomy in a woman with massive pulmonary embolus. A discussion of the indications, benefits, and disadvantages of several pharmacologic, radiologic, and surgical interventions considered in pulmonary embolus will follow.

The accuracy of limited B-mode compression technique in diagnosing deep venous thrombosis in lower extremities

BACKGROUND

Deep vein thrombosis (DVT) is prevalent in the emergency departments. Nearly 60% of them may lead to pulmonary embolism. A complete color-flow duplex ultrasound (CFDU), performed by the radiologists, is the most common diagnostic method used to detect DVT. A limited B-mode compression technique (BMCT) can also be useful for the emergency specialists visiting suspicious cases.

OBJECTIVES

The purpose of this study was to compare the sensitivity, specificity, and accuracy of a BMCT done by emergency medicine residents with that of a CFDU in diagnosing the proximal DVT of lower extremities.

METHODS

This prospective study was conducted on 74 patients (41 men and 33 women) presenting with painful and swollen lower limbs in the emergency department of Imam Khomeini Hospital. First, the affected lower extremity was examined by a BMCT carried out by one of the 2 emergency medicine residents. Then, the CFDU was performed by a radiologist blinded to the results of the BMCT. The sensitivity, specificity, and accuracy of the BMCT were compared with that of the CFDU as a gold standard.

RESULTS

The mean age of the patients was 55.16 ± 17.4 years. Positive results were reported in 35 patients (47.3%) using the 2 tests. Compared with CFDU, BMCT had a sensitivity, specificity, accuracy, positive predictive values, and negative predictive values of 100%.

CONCLUSION

These findings suggest that BMCT performed by the emergency medicine specialists to diagnose proximal DVT of lower extremities is not only an acceptable method but also less time-consuming when compared with CFDU.

A novel point of care diagnostic device: impedimetric detection of a biomarker in whole blood

There is an unmet medical need for a more reliable and earlier assessment of patients suspected of having a deep vein thrombosis. We describe a novel approach which is developing a highly reliable, accurate, portable and handheld prototype medical diagnostic device to improve radically the speed, accuracy and reliability with which DVT and related blood clotting conditions can be assessed. The device will measure whole blood concentration of D-dimer, a recognized biomarker of increased blood clotting activity, and through innovation in the development of a novel detection, measurement and reporting system, will offer the opportunity to use the test in the point of care setting. The device combines innovation in antibody bio-engineering for high specificity immunoassay-based diagnostics and nano/micro engineered impedimetric analysis electrodes incorporating a biocompatible polymer substrate with development of a disposable microfluidic manifold specifically enabling diagnostics at the point-of-first-contact.

Patient follow-up after negative lower extremity bedside ultrasound for deep venous thrombosis in the ED

OBJECTIVES

To evaluate the rate of patient compliance with follow-up ultrasound (US) examinations 5 to 7 days after emergency physician EP performed US exams to rule out lower extremity deep venous thrombosis (DVT) in the ED.

METHODS

This was a prospective observational study at a level I ED with a residency program, US training program, and an annual census of 75000. Hospital-based emergency US credentialing is available and derived from American College of Emergency Physicians guidelines. Five US-credentialed emergency physicians participated in the study. All patients who received negative lower extremity DVT US exams were eligible. All higher risk patients were given verbal and written instructions and provided with prescriptions to have a follow-up US examination 5 to 7 days after their examination in the ED. Those classified as "low risk" based on Wells criteria were excluded. After 3 months, patients were contacted via telephone and asked questions regarding their follow-up US examinations, reasons for not following up, continued symptoms, and thromboembolic events. Statistical methods included descriptive statistics.

RESULTS

One hundred fifty-nine patients were eligible for enrollment during the 10-month study period. Eighty-five patients (54%) fell into the higher risk category of these; 54 (64%) were contacted successfully. Fifteen (28%) of the patients contacted had obtained a follow-up US exam. Of the 39 who did not follow-up, 29% were told by their physician that a follow-up US was unnecessary, 21% forgot to follow-up, 8% did not follow-up for financial reasons, 16% felt better, 5% could not arrange a study, 21% were unsure. One patient died from sepsis before a follow-up scan. Two patients were diagnosed with DVT, one at 7 days follow-up and the other 9 months later (this particular patient had their 7-day scan cancelled by their primary care physician).

CONCLUSION

Patients who were instructed to obtain follow-up lower extremity US examinations to rule out propagation of unseen, distal DVTs did so at a very low rate in our study. One of the largest impediments in our study population was a patients' primary care physician who may not understand the need for a follow-up US examination.

Sensitive and quantitative, 10-min immunofluorometric assay for D-Dimer in whole blood

INTRODUCTION

Normal concentrations of D-Dimer can be used to exclude venous thromboembolism (VTE). However, methods for sensitive and quantitative D-Dimer measurements at the point-of-care (POC) are still limited.

MATERIALS AND METHODS

We developed a 10-min, non-competitive immunofluorometric assay for D-Dimer in citrated whole blood and plasma using pre-dispensed reagents dried in single assay wells. The simple, automated assay procedure comprises a 1:50 sample dilution, one-step incubation, washing, and time-resolved fluorometric measurement directly from the wet well surface.

RESULTS

The limits of detection (background + 3SD) and quantification (CV <15%) were 0.05 and 0.2 mg/L D-Dimer, respectively, and the assay was linear up to 400 mg/L. Correlations to Roche TinaQuant (r=0.726, n=200) and Biopool Auto.Dimer (r=0.190, n=149) were carried out using citrated plasma. Diagnostic sensitivity, specificity, and negative (NPV) and positive (PPV) predictive values were 98.7%, 64.4%, 99.1% and 55.1%, and 92.2%, 81.0%, 95.9% and 68.3%, respectively, using cut-off values of 0.6 and 1.0 mg/L, respectively, in outpatients with deep vein thrombosis (DVT) and/or pulmonary embolism (PE) (n=77) compared with outpatients with various other diseases (n=174). The within- and between-run CVs near the cut-off values were < or =10% in both whole blood and plasma. The 95th percentile upper range in apparently healthy individuals was 0.68 mg/L of whole blood (n=101).

CONCLUSIONS

The high sensitivity and NPV suggest that the rapid immunofluorometric assay could be valuable for rapid exclusion of VTE in outpatients. With appropriate cut-offs, the assay could potentially be used as a stand-alone test or combined with clinical probability assessment, but further studies are required.

Ultrasound diagnosis of deep venous thrombosis

The ultrasound diagnosis of deep venous thrombosis by an emergency physician is occurring with increased frequency. The examination is simple to perform and, when combined with a clinical pretest probability or D-dimer, can aid in the rapid disposition ofa patient with lower extremity pain and swelling. The technique and findings of the limited lower extremity ultrasound and the data to support its use in the emergency department are discussed.