The authors have no acknowledgments.

All procedures performed in studies involving human participants were in accordance with the ethical standards of the Duke University Health System institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The protocol was performed using inputs from the following publications3,10. Images were performed on the authors themselves for normal images and as part of routine educational ultrasound ...

<ol>
	<li>Beckman, M. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Venous+thromboembolism:+A+public+health+concern.">Venous thromboembolism: A public health concern.</a> American Journal of Preventive Medicine. 38, 495-501 (2010).</li><li>Kearon, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Natural+history+of+venous+thromboembolism.">Natural history of venous thromboembolism.</a> Circulation. 107 (23), 22-30 (2003).</li><li>Schafer, J. M., Stickles, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sonoguide:+Ultrasound+guide+for+emergency+physicians.">Sonoguide: Ultrasound guide for emergency physicians.</a> American College of Emergency Physicians. , (2020).</li><li>Pomero, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy+of+emergency+physician-performed+ultrasonography+in+the+diagnosis+of+deep-vein+thrombosis:+A+systematic+review+and+meta-analysis.">Accuracy of emergency physician-performed ultrasonography in the diagnosis of deep-vein thrombosis: A systematic review and meta-analysis.</a> Thrombosis and Haemostasis. 109 (1), 137-145 (2013).</li><li>Theodoro, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+B-mode+ultrasound+in+the+ED+saves+time+in+the+diagnosis+of+deep+vein+thrombosis+(DVT).">Real-time B-mode ultrasound in the ED saves time in the diagnosis of deep vein thrombosis (DVT).</a> American Journal of Emergency Medicine. 22 (3), 197-200 (2004).</li><li>Burnside, P. R., Brown, M. D., Kline, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+review+of+emergency+physician-performed+ultrasonography+for+lower-extremity+deep+vein+thrombosis.">Systematic review of emergency physician-performed ultrasonography for lower-extremity deep vein thrombosis.</a> Academic Emergency Medicine. 15 (6), 493-498 (2008).</li><li>Adhikari, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolated+deep+venous+thrombosis:+Implications+for+2-point+compression+ultrasonography+of+the+lower+extremity.">Isolated deep venous thrombosis: Implications for 2-point compression ultrasonography of the lower extremity.</a> Annals of Emergency Medicine. 66 (3), 262-266 (2015).</li><li>Cogo, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distribution+of+thrombosis+in+patients+with+symptomatic+deep+vein+thrombosis.+Implications+for+simplifying+the+diagnostic+process+with+compression+ultrasound.">Distribution of thrombosis in patients with symptomatic deep vein thrombosis. Implications for simplifying the diagnostic process with compression ultrasound.</a> Archives of Internal Medicine. 153 (24), 2777-2780 (1993).</li><li>Badgett, D. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Duplex+venous+imaging:+Role+for+a+comprehensive+lower+extremity+examination.">Duplex venous imaging: Role for a comprehensive lower extremity examination.</a> Annals of Vascular Surgery. 14 (1), 73-76 (2000).</li><li>Kory, P. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy+of+ultrasonography+performed+by+critical+care+physicians+for+the+diagnosis+of+DVT.">Accuracy of ultrasonography performed by critical care physicians for the diagnosis of DVT.</a> Chest. 139 (3), 538-542 (2011).</li><li>Bates, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diagnosis+of+DVT:+Antithrombotic+therapy+and+prevention+of+thrombosis,+9th+ed:+American+College+of+Chest+Physicians+Evidence-Based+Clinical+Practice+Guidelines.">Diagnosis of DVT: Antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.</a> Chest. 141 (2), 3512 (2012).</li><li>Wolf, S. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=American+College+of+Emergency+Physicians+Clinical+Policies+Subcommittee+(Writing+Committee)+on+Thromboembolic+Disease.+Clinical+policy:+Critical+issues+in+the+evaluation+and+management+of+adult+patients+presenting+to+the+emergency+department+with+suspected+acute+venous+thromboembolic+disease.">American College of Emergency Physicians Clinical Policies Subcommittee (Writing Committee) on Thromboembolic Disease. Clinical policy: Critical issues in the evaluation and management of adult patients presenting to the emergency department with suspected acute venous thromboembolic disease.</a> Annals of Emergency Medicine. 71 (5), 59-109 (2018).</li><li>Elliott, C. G., Goldhaber, S. Z., Jensen, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delays+in+diagnosis+of+deep+vein+thrombosis+and+pulmonary+embolism.">Delays in diagnosis of deep vein thrombosis and pulmonary embolism.</a> Chest. 128 (5), 3372-3376 (2005).</li><li>Musil, D., Kovacik, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delay+between+clinical+presentation+and+treatment+of+deep+venous+thrombosis+in+the+lower+limbs+and+regression+of+thrombosis.">Delay between clinical presentation and treatment of deep venous thrombosis in the lower limbs and regression of thrombosis.</a> Phlebology. 37 (2), 120-124 (2022).</li><li>Laursen, C. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focused+sonography+of+the+heart,+lungs,+and+deep+veins+identifies+missed+life-threatening+conditions+in+admitted+patients+with+acute+respiratory+symptoms.">Focused sonography of the heart, lungs, and deep veins identifies missed life-threatening conditions in admitted patients with acute respiratory symptoms.</a> Chest. 144 (6), 1868-1875 (2013).</li><li>Barosse-Antle, M. E., Patel, K. H., Kramer, J. A., Baston, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Point-of-care+ultrasound+for+bedside+diagnosis+of+lower+extremity+DVT.">Point-of-care ultrasound for bedside diagnosis of lower extremity DVT.</a> Chest. 160 (5), 1853-1863 (2021).</li><li>Frankel, H. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Guidelines+for+the+appropriate+use+of+bedside+general+and+cardiac+ultrasonography+in+the+evaluation+of+critically+ill+patients-Part+I:+General+ultrasonography.">Guidelines for the appropriate use of bedside general and cardiac ultrasonography in the evaluation of critically ill patients-Part I: General ultrasonography.</a> Critical Care Medicine. 43 (11), 2479-2502 (2015).</li><li>Bernardi, E., Camporese, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diagnosis+of+deep-vein+thrombosis.">Diagnosis of deep-vein thrombosis.</a> Thrombosis Research. 163, 201-206 (2018).</li><li>Caronia, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resident+performed+two-point+compression+ultrasound+is+inadequate+for+diagnosis+of+deep+vein+thrombosis+in+the+critically+ill.">Resident performed two-point compression ultrasound is inadequate for diagnosis of deep vein thrombosis in the critically ill.</a> Journal of Thrombosis and Thrombolysis. 37 (3), 298-302 (2014).</li></ol>

Venous thromboembolism is a common disease, affecting approximately 300,000-600,000 people in the United States annually, with serious complications including pulmonary embolism. Mortality rates in these patients range from 10%-30%2,3,4. Studies have consistently found significant delays in the diagnosis of DVT, with one prospective study of 1,152 patients across 70 medical centers identifying a delay of greater than 1 week in 2...

Deep venous thrombosis (DVT) is the formation of a thrombus in the deep peripheral veins of the extremities. It is a common and important finding, affecting about 300,000-600,000 people in the United States annually1. The propagation of DVT into a pulmonary embolism can occur in 10%-50% of patients and can be deadly, with a mortality rate of 10%-30%, which is higher than the in-hospital mortality for myocardial infarction1,2,3. The risk factors for thrombus formation include hypercoagulable states from genetic factors (family history of DVT, factor V Leiden, protein C or S deficiency), acquired factors (older age, malignancy, obesity, antiphospholipid antibodies, and others), and situational factors (pregnancy, oral contraceptives, recent surgery, travel, trauma, or prolonged immobilization, including from hospitalizations)1.
Early diagnosis of DVT in critically ill patients can expedite patient care and potentially prevent life-threatening complications such as pulmonary embolism, pulmonary infarct, and cardiac involvement1,2,3. A systematic review by Pomero et al. showed a pooled prevalence of 23.1% for DVT in critically ill patients4. Screening for lower extremity DVT has traditionally been performed by radiology ultrasound technicians conducting comprehensive whole-leg duplex exams including both grayscale compression ultrasound and color/spectral Doppler. However, several smaller or community clinical sites lack the direct availability of a sonographer during certain times of the day, such as on nights or weekends, thus creating a delay in patient care5. More recently, acute care providers have devised methods of screening for proximal lower extremity DVTs using point-of-care ultrasound (POCUS)-focused imaging protocols, which demonstrate similarly high sensitivity and specificity in critically ill patients3,4,6. Proximal lower extremity DVTs are defined as DVTs occurring anywhere in the groin, thigh, or knee within the femoral or popliteal venous system. Falling outside of this category are DVTs in the following locations: calf veins (where DVTs are of uncertain clinical significance) and pelvic veins (i.e., the common, external, and internal iliac veins), which are only detectable indirectly using the color and spectral Doppler portion of consultative lower extremity venous ultrasound exams2,3.
Understanding the typical anatomic distribution of DVTs makes performing these bedside exams rapid and easy. First, 70%-99% of proximal lower extremity DVTs involve the femoral or popliteal regions7,8,9. Second, grayscale compression ultrasound is a simple and accurate method for evaluating DVTs; when enough pressure is applied to indent an adjacent artery, normal veins should collapse fully, whereas veins harboring a DVT will not. Combining these principles, the two-zone or three-zone lower extremity DVT POCUS examinations center on compression ultrasound of veins in the inguinal, thigh, and popliteal areas. These techniques have been clinically validated in prior intensive care and emergency medicine studies, demonstrating high sensitivity (96.1%, with a 95% confidence interval (CI) of 90.6%-98.5%) and specificity (96.8%, with a 95% CI of 94.6%-98.1%), with high overall diagnostic accuracy (95%)3,4,6. However, in the experience of the authors, the DVT POCUS exam remains grossly underutilized in the care of critically ill patients, possibly because clinicians are not familiar with the image acquisition sequence. This narrative review with associated visual aids describes an image acquisition protocol for performing a POCUS exam to screen for proximal lower extremity DVTs to assist providers in proper expedited image acquisition during clinical care.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Edge 1 ultrasound machine</td>
			<td>SonoSite</td>
			<td>n/a</td>
			<td>Used to obtain normal images/clips</td>
		</tr>
		<tr>
			<td>SPARQ ultrasound machine</td>
			<td>Philips</td>
			<td>n/a</td>
			<td>Used to obtain abnormal images/clips</td>
		</tr>
	</tbody>
</table>

point-of-care ultrasound screening for proximal lower extremity deep venous thrombosis

Acute lower extremity deep venous thrombosis (DVT) is a serious vascular disorder that requires accurate and early diagnosis to prevent life-threatening sequelae. While whole leg compression ultrasound with color and spectral Doppler is commonly performed in radiology and vascular labs, point-of-care ultrasound (POCUS) is becoming more common in the acute care setting. Providers appropriately trained in focused POCUS can perform a rapid bedside examination with high sensitivity and specificity in critically ill patients. This paper describes a simplified yet validated approach to POCUS by describing a three-zone protocol for lower extremity DVT POCUS image acquisition. The protocol explains the steps in obtaining vascular images at six compression points in the lower extremity. Beginning at the level of the proximal thigh and moving distally to the popliteal space, the protocol guides the user through each of the compression points in a stepwise manner: from the common femoral vein to the femoral and deep femoral vein bifurcation, and, finally, to the popliteal vein. Further, a visual aid is provided that may assist providers during real-time image acquisition. The goal in presenting this protocol is to help make proximal lower extremity DVT exams more accessible and efficient for POCUS users at the patient&#39;s bedside.

We describe the interpretation of proximal lower extremity DVT POCUS in patients with an initial suspected DVT.
The attached Figure 2 demonstrates negative POCUS ultrasound images for DVT in the left and right lower extremities, with multi-point compression from the proximal to distal veins as demonstrated in Figure 1 (from thigh to knee). In a negative DVT study, the veins are completely collapsible, with the anterior wall touching t...

Watch this Scientific Journal Video about Point-Of-Care Ultrasound Screening for Proximal Lower Extremity Deep Venous Thrombosis at JoVE.com

Point-Of-Care Ultrasound Screening for Proximal Lower Extremity Deep Venous Thrombosis

Traditionally, lower extremity deep venous thrombosis (DVT) is diagnosed by radiology-performed venous duplex ultrasound. Providers appropriately trained in focused point-of-care ultrasound (POCUS) can perform a rapid bedside examination with high sensitivity and specificity in critically ill patients. We describe the scanning technique for focused POCUS DVT lower extremity examination.

Acute lower extremity deep venous thrombosis (DVT) is a serious vascular disorder that requires accurate and early diagnosis to prevent life-threatening ...

Our protocol describes a simplified yet validated approach to diagnostic point-of-care ultrasound by describing a three-zone protocol for lower extremity DVT image acquisition. Providers appropriately trained in focused point-of-care ultrasound can perform a rapid bedside DVT examination with high sensitivity and specificity in critically ill patients. Diagnostic POCUS exams can expedite the diagnosis of DVT and thereby initiate earlier treatment with potentially decreased complication rates and improved patient clinical outcomes.Key steps for appropriate DVT image acquisition include proper patient positioning, adequate gain and depth, and complete compression of the veins'vessel walls to ensure no thrombus is present. Select the high frequency linear transducer for the deep venous thrombosis or DVT scan to ensure a high resolution image of the veins. Next, set the depth, gain, and focus.Set the depth so that the target vessels appear in the middle one-third of the ultrasound screen by pressing the up or down depth button. Then set the gain so that the vessels contain a few spots of gray but are otherwise black by pressing the right or left gain button and turning the dial. If the machine has the capability, aim the focus beam at or slightly below the level of the target vessels by clicking the box on the screen and moving it while holding down the button and then release.Set the machine mode. Click on B-mode, which is a two-dimensional gray scale ultrasound exam, to obtain both the non-compressed and compressed images. For optimal scanning ergonomics, place the machine with the ultrasound in a direct line of sight with the ultrasound probe.Before scanning, expose the patient's entire leg from the groin to the knee. Place the patient supine for DVT examination of the common femoral and femoral veins. Place the patient in the frog-leg position to enable better visualization and scanning of the distal veins.For B-mode scanning of the groin and thigh, apply gel to the patient's skin in a linear path that traces out the expected path of the ultrasound transducer to increase the efficiency of motion. For B-mode scanning of the knee, apply gel to the transducer itself, as a generous gel application will facilitate the scanning efficiency. Next, for transducer orientation, place the transducer in a transverse position with the orientation marker directed toward the patient's right side to ensure that images captured during scanning correspond to the anatomical direction of the structures.Place the probe perpendicular to the path of the vein to visualize the vein in a short axis view. Center the venous structure on the screen. Add long axis imaging in ambiguous cases by rotating the probe 90 degrees so the marker points towards the patient's head.For compression sequence, begin scanning immediately coddle to the inguinal crease. Progress distally sequentially with downward compression and then release at each point. Compress such that the entire vein collapses with the anterior wall touching the posterior wall while the artery remains pulsatile.Do not apply resting surface pressure between each compression, as it can obscure the visualization of the veins. The vein should collapse fully when enough pressure is applied with the transducer to indent an adjacent artery. Click save clip and compress.Then release the common femoral vein or CFV and femoral artery or FA just below the inguinal ligament. Slide the probe distally about one centimeter and record the same compression and release technique at the CFV and FA at the intake of the great saphenous vein or GSV. Click save clip, then compress and release the probe at the CFV at the bifurcation of the FA into the superficial femoral artery or SFA and deep femoral artery or DFA.Between the SFA and DFA, there will be a lateral perforator vein draining from the lateral to medial into the CFV. Ensure that both the lateral perforator vein and GSV are compressible. Click save clip, then compress and release the probe at the CFV at the bifurcation of the CFV into the femoral vein or FV and deep femoral vein or DFV.Again, click save clip, compress, and release the probe at the popliteal vein behind the knee. Once points one to five are fully compressible, scan the FV along the thigh from proximal to distal until the vein disappears into the adductor canal. During this scanning process, attempt to compress the vein approximately every one to two centimeters.In this study, left leg vascular anatomy with negative and positive lower extremity DVT examples in transverse views, are shown here. In a negative DVT study, the veins are completely collapsible with the interior wall touching the posterior wall during compression ultrasound in all the zones. In a positive DVT study, proximal vein POCUS can both directly visualize a thrombus or detect non-compressibility of the proximal veins, which is diagnostic of a non-occlusive thrombus.The protocol explains the steps in obtaining DVT images at six compression points in the lower extremity from the proximal thigh, moving distally, to the popliteal space.

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10.5K vistas.  Duke University School of Medicine. Nuestro protocolo describe un enfoque simplificado pero validado para el ultrasonido de diagnóstico en el punto de atención al describir un protocolo de tres zonas para la adquisición de imágenes de TVP de las extremidades inferiores. Los proveedores debidamente capacitados en ultrasonido focalizado en el punto de atención pueden realizar un examen rápido de TVP junto a la cama con alta sensibilidad y especificidad en pacientes críticamente enfermos. Los exámenes POCUS de diagnóstico...