Point of Care Ultrasound For Family Practice Residents April 25, 2018 Kamloops Prepared by Shane Barclay MD

Learn the techniques for: Vascular Access. DVT scanning. Goals and Objectives Learn the techniques for: Vascular Access. DVT scanning. Bloom’s taxonimy

Vascular access Peripheral Line access. Central line access.

Peripheral IV access This technique is for routine, non urgent IV access. In a trauma/resuscitation, if after 2 unsuccessful IV attempts, go to an intraosseous device. Used primarily for arm IV access, either above or below the elbow. However can be used for any vein access as well.

Arm anatomy

Transverse arm anatomy

Transverse arm anatomy Right Arm

Transverse arm anatomy

Transverse arm anatomy Median nerve Basilic vein Brachial artery Brachial veins Humerus Right Arm

Peripheral IV access So, given the anatomy, try for cannulation of the cephalic vein as it is isolated with no other important structures nearby. By contrast, the brachial vein is within the brachial neurovascular bundle.

Peripheral IV access Success is greatly improved with veins being: Visible for more than 1 cm in length (ie no angles or bends in the vein) Vein diameter greater than 3 mm. Vein less than 1.5 cm deep in the tissue.

Tips for Peripheral IV access Externally rotate the arm Use a linear array probe, depth at minimum, frequency to maximum. Using a Q tip or other small blunt instrument, indent the skin over the vein with the probe to identify the vein. Use light probe pressure otherwise the vein will collapse. If above the elbow, use local anesthetic as IV starts above the elbow are painful.

Tips for Peripheral IV access 6. You can either mark a proximal and distal identification of the vein with marker pen. Note the depth of the vein. Then use IV cannula to attempt IV start. 7. Other methods are ‘direct visualization, either ‘longitudinal’ or ‘transvers’ cannulation which allows you to visualize the IV going in. Transverse visualization is much harder.

video on u/s guided IV cannulation The web page on REMSTARBC.ca has videos on peripheral IV cannulation.

External Jugular vein And often forgotten IV access site is the external jugular. It can be relatively easy to cannulate if you are in a situation without intraosseous devices and you do not feel comfortable doing a central line. The video on the web page shows the technique.

Central line access 95% of internal jugular veins are either above or lateral to the internal carotid artery. Message: palpation of the carotid is not that accurate a landmark. 22% 50% 22%

Central line access Tips: Turn the head slightly but not too far as this can cause the Internal Jugular (IJ) to move directly over (anterior) or even medial to the carotid artery. Avoid neck flexion or extension. Start scanning just above the clavicle to identify the IJ, for if the patient is hypovolemic the IJ may be flat more cephalad. However try not to cannulate right above the clavicle as you risk a lung puncture.

Central line access Tips: 5. If the diameter is less than 5 mm – caution. Maybe look for other IV sites. 6. Start with the probe transverse over the IJ and confirm with compression. 7. A needle entering the skin at 45 degrees will have to travel 1.4 times the depth to penetrate the vein. 8. In longitudinal plane, remember the ‘width’ of the probe beam is barely as thick as a credit card!

Central line access The video on the REMSTARBC.ca website covers more of the details of central line insertion. Recommended viewing.

POCUS for DVT POCUS of the proximal femoral and popliteal veins has a sensitivity for DVT of ~ 90-100% because the vast majority of DVTs occur at the bifurcation.

POCUS for DVT Technique for Femoral DVT: 1. Using linear array probe set at ~ 5 – 6 cm depth. 2. Have patient either lie flat on the stretcher or in reverse Trendelenberg to help dilate the veins. 3. Externally rotate the thigh 20 degrees. 4. Know your anatomy.

POCUS for DVT Technique for Femoral DVT: 5. Place probe in transverse plane just below inguinal ligament. 6. Identify Common Femoral Vein (CFV) and then slide proximally until you loose the vein in bowel gas. 7. Then start sliding distally. 8. Assess from the proximal CFV until a point 2 cm distal to where the superficial and deep vein divides. 9. Compress the vein every cm, until the vein collapses.

POCUS for DVT Technique for Femoral DVT: 10. The amount of pressure to collapse the vein should never be more than the pressure to collapse the artery. 11. If the artery begins to collapse but the vein has not yet collapsed, consider the diagnoses of acute DVT. 12. Thrombi usually develop at the bifurcations.

POCUS for DVT Technique for Femoral DVT: 13. Continue to compress the CFV until it bifurcates into the Deep Femoral vein and the CFV becomes the “Femoral Vein” or the “Superficial Femoral Vein”. 14. Continue for another 2-3 cm along the Femoral Vein.

POCUS for DVT Technique for Popliteal DVT: The knee should be flexed 10 – 30 degrees or the popliteal vein can collapse. Patient can turn on their side with affected leg on top, or sit with leg over edge of the stretcher. Place probe behind the knee. Find the Popliteal Vein and go proximally until you see the Popliteal artery and vein lateral to each other. Continue down until you see all 3 posterior tibial veins.

POCUS for DVT Positive Scan Any vein that fails to completely collapse under pressure of the probe at any level is strongly suggestive of DVT. Failure to see an echogenic clot is NOT a sign to exclude a DVT. Note: sensitivity of calf POCUS is low – 35 – 70%. Note: a negative D-dimer and a negative 2 point compression POCUS has a less than 1% risk of DVT at 3 month follow-up.

POCUS for DVT False Negative Scans: Pelvic vein DVT Duplicate Popliteal Vein False Positive Scans: Lymph nodes (can use color doppler or rotate the probe) Superficial thrombophlebitis in the GSV as it goes behind the knee. Baker’s cyst. (no flow on Doppler)

POCUS for DVT Clinical Algorithm: D-dimer negative and POCUS negative – unlikely DVT. D-dimer positive and POCUS negative - either start on LMWH and rescan the next day or if possible get formal ultrasound next day +/- start LMWH. D-dimer positive and POCUS positive. Start LMWH and get formal ultrasound at some point to further evaluate size and location.

The end.