Clinical application
Assess for leg vein thrombosis (Figure 4.12).
BOTTOM LINE/CLINICAL PEARLS
Elevate head of bed or place patient in reverse Trendelenburg to maximize venous distension of lower extremities.
Do not assume an anechoic lumen is a patent lumen. An acute clot may be anechoic.
Baker’s cyst or lymph nodes may be mistaken for clot.
Table 4.5 RUSH exam protocol.
| RUSH exam | Hypovolemic shock | Cardiogenic shock | Obstructive shock | Distributive shock |
|---|---|---|---|---|
| Pump | Hyperconstractile heart Small heart size | Hypoconstractile heart Dilated heart size | Pericardial effusion RV strain Hyperconstractile heart | Hyperconstractile heart (early sepsis) Hypoconstractile heart (late sepsis) |
| Tank | Flat IVC Flat IJV Peritoneal fluid Pleural fluid | Distended IVC Distended IJV Lung rockets Pleural effusions, ascites | Distended IVC Distended IJV Absent lung sliding (PTX) | Normal/small IVC Normal/small IJV Pleural fluid (empyema) Peritoneal fluid (peritonitis) |
| Pipes | AAA Aortic dissection | Normal | DVT | Normal |
Management/treatment algorithm
Multiple point‐of‐care US protocols have been proposed for the rapid diagnosis of undifferentiated shock.
The Rapid Ultrasound in SHock (RUSH) exam is a stepwise resuscitative US protocol developed in 2010 that incorporates many of the core US principles proposed and validated in prior studies (Table 4.5).
The RUSH exam simplifies bedside physiologic assessment into three steps: evaluation of ‘the pump,’ ‘the tank,’ and ‘the pipes.’
Reading list
1 Koenig SJ, Narasimhan M, Mayo PH. Thoracic ultrasonography for the pumonary specialist. Chest 2011; 140(5):1332–41.
2 Mayo PH, et al. American College of Chest Physicians/La Société de Réanimation de Langue Francaise Statement on Competence in Critical Care Ultrasonography. Chest 2009; 135:1050–60.
3 Mayo PH, Doelken P. Pleural ultrasonography. Clin Chest Med 2006; 27:215–27.
4 Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically ill. Emerg Med Clin N Am 2010; 28(1):29–56.
5 Schmidt G, Koenig S, Mayo PH. Shock: ultrasound to guide diagnosis and therapy. Chest 2012; 142(4):1042–8.
6 Seif D, et al. Bedside ultrasound in resuscitation and the rapid ultrasound in shock protocol. Crit Care Res Pract 2012; 2012:1–14.
7 Volpicelli G, et al. Point‐of‐care multiorgan ultrasonography for the evaluation of undifferentiated hypotension in the emergency department. Intensive Care Med 2013; 39:1290–8.
Suggested websites
www.emcrit.org/rush‐exam/original‐rush‐article/
Images
Figure 4.1 Probe types. (A) Linear. (B) Phased array. (C) Large curvilinear.
Figure 4.2 Standard bedside ECHO views. (A) Parasternal long axis, systole; aortic valve open, MV closed. (B) Parasternal short axis, mid‐papillary muscle level. (C) Apical four chamber view. (D) Subxiphoid view.
Figure 4.3 Right ventricular strain. RV size exceeds LV size; RV pressure flattens or bows interventricular septum into LV during diastole (apical four chamber window).
Figure 4.4 IVC transitions into RA to confirm visualization of IVC versus abdominal aorta.
Figure 4.5 M‐mode chest with ‘seashore’ signal. The thicker first horizontal line (arrow) is the pleural line. Above the pleural line are (normal) horizontal lines due to the chest wall. Below the pleural line, where the lung is present, note the ‘sandy’ appearance diagnostic of lung sliding. Lung sliding rules out a complete pneumothorax.
