BRIPPED Protocol:
The BRIPPED scan is an effective screening tool for shortness of breath that evaluates pulmonary B-lines, Right ventricle size and strain, Inferior Vena Cava (IVC) collapsibility, Pleural and Pericardial Effusion, Pneumothorax, Ejection Fraction of the left ventricle, and lower extremity Deep Venous Thrombosis.
B-lines: Sonographic pulmonary B-lines have been shown to correlate with congestive heart failure.1-4, 7, 8 A high-frequency linear probe is used to evaluate at minimum 2 mid clavicular apical lung windows.
RV strain: Right ventricular (RV) enlargement can be caused by a Pulmonary Embolus (PE), acute RV infarct, Congestive Heart Failure (CHF), pulmonary valve stenosis or pulmonary hypertension, and is a risk factor for early mortality in PE.9 A low frequency phased array probe is used to evaluate RV strain in an apical 4 chamber view.
IVC-size and collapsibility: Using an IVC size cut off of 2.0 cm has been shown to have a sensitivity of 73% and specificity of 85% for a Right Atrial Pressure (RAP) above or below 10 mmHg. The collapsibility during forced inspiration of less than 40% has even greater accuracy for elevated RAP (sensitivity 91%, specificity 94%, NPV 97%).10 A low frequency phased array or curvilinear probe is used to visualize the IVC long axis, and dynamic imaging is used to assess collapsibility as either complete or less than 40%.
Pneumothorax: Bedside ultrasound is more accurate than supine chest x-ray with diagnostic ability approaching that of CT. 11, 12 The same windows for B-lines are utilised for pneumothorax screening. Additionally, any area of decreased breath sounds or crepitus palpated along the chest wall is evaluated for pneumothorax with a high-frequency linear probe.
Pleural effusion: EUS has been shown to have an accuracy similar to a CXR for evaluation of pleural effusion.6, 7 A low frequency phased array or curvilinear probe is used to evaluate each midaxillary line at the costophrenic angle in the sitting patient.
Pericardial effusion: EUS has a sensitivity of 96% and specificity of 98% compared to formal echocardiography. 13 A low frequency phased array probe is used to evaluate pericardial effusion from an apical 4 chamber view and a parasternal long axis view of the heart.
EF: The qualitative assessment of left ventricular ejection fraction by emergency physicians has been shown to correlate well with an assessment by a cardiologist.14-17 The same low-frequency probe and parasternal long axis used to evaluate pericardial effusion are used to evaluate ejection fraction. Dynamic qualitative assessment of ejection fraction is classified as normal, depressed, or severely depressed.
DVT in lower extremities: Ultrasound was performed by emergency physicians using a two-point compression venous ultrasound on patients with suspected lower extremity DVT. This approach had a 100% sensitivity and 99% specificity in diagnosing DVT, compared to a reference venous ultrasound in radiology.18 A high-frequency linear probe evaluates compressibility of the common femoral and popliteal veins with dynamic scanning. If pre-test probability is higher for DVT, then additional fields are included, starting below the inguinal ligament at the common femoral vein, and each segment of vessel is compressed every 2 cm to the trifurcation of the popliteal artery distally.
The BRIPPED protocol can be performed in its entirety from a head to toe approach, switching between transducers, or completing the exam with one transducer then switching to the next. An example of the latter would be to first use the low-frequency probe to evaluate the parasternal long axis and apical 4 chambers, noting the presence or absence of pericardial effusion, ejection fraction, and RV strain. Then the long axis of the IVC is evaluated for dynamic collapsibility. Moving laterally, the costophrenic angles are evaluated bilaterally for pleural effusion. The probe is switched to the high-frequency probe to evaluate each lung apex is evaluated in the midclavicular line for the presence of pneumothorax and B lines. Lastly, the dynamic 2 point DVT screening is performed with compression ultrasound. The BRIPPED protocol and other bedside ultrasound resources can be viewed here:
Intravenous Access
Patients presenting to the Emergency Department (ED) with shortness of breath may have characteristics that impede intravenous (IV) access. Such characteristics may include hypotension, dialysis dependence, morbid obesity, or histories of diabetes, sickle cell disease, or IV drug use. One prospective observational study identified nearly one in every 9 to 10 adults presenting to an urban ED had difficult venous access requiring 3 or more IV attempts.19 If peripheral IVs are not established, patients may need a central venous catheter placed for life-saving medications administered. In addition to requiring physician skill, central venous catheter insertion carries a risk of complications including infection, arterial puncture or aneurysm, and pneumothorax. Ultrasound-guidance for peripheral IV placement (UGPIV) has prevented the need for central venous catheter placement in 85% of patients with difficult IV access.20 UGPIV has been performed by Emergency Medical Technicians (EMTs) in prehospital settings, as well as nurses and physicians. Patients who have been identified as having difficult access, have higher patient satisfaction scores when ultrasound is used in peripheral IV access attempts.21
Frequently, the large veins of the antecubital fossa are sufficient to place large bore peripheral IVs needed for resuscitation. The brachial and basilica veins are easy to locate. The brachial artery is generally flanked by 2 smaller veins and the median nerve. Anatomically, these structures are medial to the insertion of the medial biceps tendon. This tendon is palpable in the antecubital fossa as the patient flexes then extends the elbow. The basilic vein is located medial to the brachial vessels. Generally, it is more superficial, larger, and does not have an accompanying artery or nerve at the level of the antecubital fossa. As you move proximally up the arm (towards the head) the basilic vein dives deeper toward the humerus, and longer angiocatheters may be required for cannulation.
When considering vascular access, there are 2 views, a short and long axis view. Cannulation from the short axis is considered “out of plane” since the needle is perpendicular to the probe. A short axis approach “looks” at a cross-section of the vessel. Long axis uses and “in-plane” approach with the needle entering from the probe marker end, and “looks” along the length of the vessel. While both approaches may be used for UGPIV placement, the benefit for the short axis is the ability to identify target veins as well as accompanying non-target (arteries and nerve) structures.
Identify the Vein: Remember the C’s
The two C’s to remember for UGPIV access or for central venous cannulation are Compression and Color (or Power) Doppler. Veins are thinner walled and more easily compressed than arteries. This author advocates for finding a vessel first in the short plane, and compressing the vessel to ensure it is indeed a vein, rather than a lessor non-compressible artery. Colour or Power Doppler may be utilised to determine if the pulsatile flow is consistent with an artery or vein. Color Doppler uses red and blue to determine flow towards or away from the probe respectively. Power Doppler detects flow without concern for direction. Colour should not be relied on alone to determine arterial or venous flow due to the colour scale setting can be flipped or reversed, or aliasing can occur. Arterial flow is more pulsatile than venous. Venous flow may require distal augmentation (by squeezing the forearm distal to the probe) to appreciate the blush of colour. Once the target vein is identified, the depth from the skin surface should be noted. A common mistake is to use an angio catheter that is too long or too short. A general rule of thumb is to use a catheter length that is more than twice the depth of the vessel to ensure at least half the catheter lies within the vein. Sterile ultrasound gel should be used, with a covered probe to prevent infection. To prevent the risk of multiple punctures, this author advocates for first bouncing the needle on the skin over the point of entry. The tissue should deform at the top of the screen, and confirm the needle is over the target vessel. One the skin is punctured, the needle tip is kept in view by angling the ultrasound probe until the target vessel is punctured.
To confirm placement, either a “bubble study” with agitated saline may be performed or Color (or Power) Doppler utilised to visualise saline flow through the cannulated vessel. A vessel that is not properly cannulated will demonstrate extravasation of saline around the vessel into the tissue before the tissue swells to a degree which is palpable on the surface of the skin.
References
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10 Kucher, N., et al., Prognostic role of echocardiography among patients with acute pulmonary embolism and a systolic arterial pressure of 90 mm Hg or higher. Arch Intern Med, 2005; 165(15):1777-81.
11 Brennan, J.M., et al., Reappraisal of the use of inferior vena cava for estimating right atrial pressure. J Am Soc Echocardiogr, 2007; 20(7):857-61.
12 Kirkpatrick, A.W., et al., Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the Extended Focused Assessment with Sonography for Trauma (EFAST). J Trauma, 2004; 57(2): 288-95.
13 Xirouchaki N, Magkanas E, Vaporiid K, et al., Lung ultrasound in critically ill patients: Comparison with bedside chest radiography. Intensive Care Med, 2011; 37(9):1488-1493.
14 Mandavia, D.P., et al., Bedside echocardiography by emergency physicians. Ann Emerg Med, 2001; 38(4):377-82.
15 Alexander, J.H., et al., Feasibility of point-of-care echocardiography by internal medicine house staff. Am Heart J, 2004; 147(3): 476-81.
16 Moore, C.L., et al., Determination of left ventricular function by emergency physician echocardiography of hypotensive patients. Acad Emerg Med, 2002; 9(3):186-93.
17 Randazzo, M.R., et al., Accuracy of emergency physician assessment of left ventricular ejection fraction and central venous pressure using echocardiography. Acad Emerg Med, 2003; 10(9): 973-7.
18 Crisp, J.G., L.M. Lovato, and T.B. Jang, Compression ultrasonography of the lower extremity with portable vascular ultrasonography can accurately detect deep venous thrombosis in the emergency department. Ann Emerg Med, 2010; 56(6): 601-10.
19 Fields, J.M., Piela, N.E., Au, A.K., Ku, B.S., Risk factors associated with difficult venous access in adult ED patients. Am J Emerg Med. 2014 Oct; 32(10):1179-82.
20 Au, A.K., Rotte, M.J., Grzybowski, R.J., Ku, B.S., Fields, J.M., Decrease in central venous catheter placement due to use of ultrasound guidance for peripheral intravenous catheters. Am J Emerg Med. 2012 Nov;30(9):1950-4.
21 Schoenfield, E., Shokoohi, H., Boniface, K. Ultrasound-guided peripheral intravenous access in the emergency department: patientcentered survey. West J Emerg Med. 2011 Nov;12(4):475-7.
Virginia M Stewart MD RDMS RDCS RDMSK
Emergency Ultrasound Director, Emergency Ultrasound Fellowship Director
Department of Emergency Medicine
Tel: (757) 594 2000
