Ultrasound diagnosis of deep venous thrombosis

Differential Diagnosis of Acute Calf Pain and Swelling with Emergency Ultrasound

Acute calf pain and swelling are common causes of emergency department attendance. Differential diagnoses may mimic each other causing confusion and uncertainty in management. With emergency ultrasound, most of the differential diagnoses for acute calf pain and swelling can be identified with confidence. We present two cases of calf pain and swelling utilising ultrasound to clarify the diagnosis.

Advanced Therapies in Venous Thromboembolism

Advanced therapies are available for both deep venous thrombosis and pulmonary embolism when anticoagulation alone is not sufficient to improve clinical outcomes. In some cases, clinical deterioration ensues despite anticoagulation, and this requires unique techniques that can ameliorate the clinical course. Such advancements are described in this upcoming article.

Critical Care Basic Ultrasound Learning Goals for American Anesthesiology Critical Care Trainees: Recommendations from an Expert Group

OBJECTIVE

In this review, we define learning goals and recommend competencies concerning focused basic critical care ultrasound (CCUS) for critical care specialists in training.

DESIGN

The narrative review is, and the recommendations contained herein are, sponsored by the Society of Critical Care Anesthesiologists. Our recommendations are based on a structured literature review by an expert panel of anesthesiology intensivists and cardiologists with formal training in ultrasound. Published descriptions of learning and training routines from anesthesia-critical care and other specialties were identified and considered. Sections were written by groups with special expertise, with dissent included in the text.

RESULTS

Learning goals and objectives were identified for achieving competence in the use of CCUS at a specialist level (critical care fellowship training) for diagnosis and monitoring of vital organ dysfunction in the critical care environment. The ultrasound examination was divided into vascular, abdominal, thoracic, and cardiac components. For each component, learning goals and specific skills were presented. Suggestions for teaching and training methods were described.

DISCUSSION

Immediate bedside availability of ultrasound resources can dramatically improve the ability of critical care physicians to care for critically ill patients. Anesthesia--critical care medicine training should have definitive expectations and performance standards for basic CCUS interpretation by anesthesiology--critical care specialists. The learning goals in this review reflect current trends in the multispecialty critical care environment where ultrasound-based diagnostic strategies are already frequently applied. These competencies should be formally taught as part of an established anesthesiology-critical care medicine graduate medical education programs.

Descriptive analysis of a bilingual and cross-cultural introductory ultrasound course facilitated by simultaneous translation

Study objective

The increasing use of focused ultrasonography by non-specialists emphasizes the need for standardized trainings. We analyze physicians’ skill acquisition after the implementation of an ultrasound introductory course. As part of an international educational collaboration, we also investigate the impact on training efficiency of language and cultural differences.

Methods

We organized a 2-day training for emergency physicians. Lectures were given in French with simultaneous Chinese translation. At the end of the training, physicians were asked to conduct, on healthy live models, a complete ultrasound examination including 11 images and two procedures (cardiac, abdominal, vascular and bone ultrasonography). Quality was assessed by two independent observers and a 60-s time limit per view/procedure was set. Ultrasound examination was successful only if both quality and length objectives were achieved.

Results

Seventeen attending emergency physicians participated in the study. None withdrew from the training. The overall success rate of image and procedure acquisition was 97.3% (364 out of 374). Six physicians had failed cases and mainly on cardiac examination (eight failures out of ten). Failure rate for the complete sequence (1 or more failure out of the 11 images/procedure) was 24% (8/34). Median time to capture a single image was 13 s (5–24), while the whole examination took 182 s (141–238) excluding time for probe change.

Conclusion

A 2-day introductory course on focused ultrasonography leads to very good skill acquisition. Language and cultural differences do not seem to alter training efficiency.

A case of lower extremity venous thrombosis in the pediatric emergency department: associations with May-Thurner syndrome and isotretinoin use

Unilateral calf swelling and pain is not a common complaint in the pediatric emergency department. We present a case of a 17-year-old adolescent boy with no past medical history who presented with left leg swelling and pain while taking prednisone and isotretinoin. He was found to have an extensive occlusive thrombus throughout the deep venous system in his left leg. He was later diagnosed with May-Thurner syndrome, an anatomic variant in which the right iliac artery compresses the left iliac vein. We review the differential diagnosis, diagnostic workup, and initial ED management of deep venous thrombosis and provide a brief discussion of May-Thurner syndrome and the association of isotretinoin and vascular thrombi.

[Modern ultrasound diagnostics of deep vein thrombosis in lung embolism of unknown origin]

PURPOSE

We compared innovative ultrasound techniques such as tissue harmonic imaging (THI) and cross-beam technique with speckle reduction imaging (SRI) to conventional fundamental B scan in the diagnosis of deep vein thrombosis.

MATERIAL AND METHODS

We investigated a total number of 185 patients with clinical symptoms of acute vein thrombosis. We documented the thrombosis in the patients using multifrequency ultrasound probes (5-7 MHz, 6-9 MHz, 9-14 MHz, Logig 9, GE) and recorded ultrasound sequences in fundamental B scan, THI, and cross-beam technique with SRI (grade 2). Three blinded ultrasound investigators ranked the marking of the thrombosis in each of these image modalities and graded them with the numbers 5 = weak, 4 = moderate, 3 = satisfactory, 2 = good, and 1 = excellent. We calculated the median and a t-test for each of these image modalities.

RESULTS

We diagnosed 115 thromboses (62%) in 185 investigated patients. This group could be divided as follows: 11 patients (6%) with three-level thrombosis, 37 patients (20%) with two-level thrombosis, and 67 (36%) with one-level thrombosis. The one-level thrombosis group included five (3%) patients with muscle vein thromboses, seven (4%) cases of thrombophlebitis without involvement of the deep vein system, and three (2%) cases of thrombophlebitis with involvement of the deep vein system. The t-test for unconnected samples showed significant differences (p <0.05) in iliac veins and highly significant differences (p <0.001) in the veins of the lower extremity due to the superior capabilities for detection of thrombosis using the cross-beam technique with SRI compared to THI and the fundamental B scan.

CONCLUSION

The use of high-resolution linear ultrasound probes with the concomitant application of THI and cross-beam technique with SRI facilitates the diagnosis of deep vein thrombosis. The employment of these new ultrasound modalities is an advantage in distinguishing the veins from the surrounding tissue structures and helps in evaluating the compressibility of venous vessels.

A patient with deep vein thrombosis presenting to a chiropractic clinic: a case report

OBJECTIVE

The objective of this article is to present and discuss a case of deep vein thrombosis in a chiropractic clinic setting.

CLINICAL FEATURES

A 33-year-old male patient presented for follow-up chiropractic care for a long-term low back complaint. A working diagnosis of facet joint syndrome was made. Despite improvement of low back symptoms, the patient experienced right-sided groin pain. The patient was referred to the hospital with a provisional diagnosis of deep vein thrombosis.

INTERVENTIONS AND OUTCOMES

The patient consulted a physician, and within 2 hours of chiropractic consultation, his entire leg had become painful. Doppler ultrasound revealed extensive thrombosis. He was placed on heparin and was hospitalized for 8 days. On discharge, a full-length right leg stocking and moderate exercise were recommended. Consecutive checkups were scheduled with the clot almost resolved at 19 months postdiagnosis.

CONCLUSION

This case report highlights the importance for the manipulative therapist to be aware of cardiovascular disease mechanisms and associated risk factors, so comanagement via referral to the appropriate specialist can occur.

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.