Patients who present to the emergency department (ED) commonly report chest pain, shortness of breath, or dyspnea on exertion. They are often tachycardic or even hypotensive. Unfortunately, history and physical examination alone often lack the sensitivity and specificity to accurately diagnose the underlying etiology. Focused bedside echocardiography (FBE) is a valuable and increasingly available imaging modality that can be used to better manage these patients.
When emergent interventions such as intubation, fluid resuscitation, or pressors are indicated, FBE should not delay the initiation of such treatment. While FBE can be difficult to perform in patients presenting in extremis or during ongoing resuscitations, the information obtained through FBE can be lifesaving. Anesthesia is generally not necessary for the sonographic evaluation of the heart, great vessels, and pleural spaces.
Benefits of FBE include the following:
Decreases time to diagnosis for pericardial effusions
Helps diagnose pericardial effusions in cases of pulseless electrical activity
Helps assess left ventricular function, even with limited views
or in the setting of hypotension
Helps assess volume status and central venous pressure (CVP)
Helps diagnose decompensated congestive heart failure (FBE has been shown in some instances to even be more accurate than chest radiographs.
It can be used alone or in conjunction with N-terminal pro-brain-type natriuretic peptide [NT-ProBNP] levels to help differentiate between congestive heart failure [CHF] and chronic obstructive pulmonary disease [COPD] in patients with shortness of breath.
Helps diagnose deep vein thrombosis (DVT)
While not sensitive for pulmonary embolism (PE), FBE findings can prompt pursuit of this diagnosis or risk stratify those patients who are found to have PE.
Can be learned and integrated into clinical practice with limited training
Can be performed at the bedside to avoid removing critically ill patients from the immediate clinical area
The components of FBE include the following:
Subxiphoid 4-chamber view
Parasternal long-axis and short-axis views
Apical 4-chamber view
Subxiphoid long-axis view of the inferior vena cava (for assessment of CVP and volume status)
Assessment of the internal jugular vein (for assessment of CVP and volume status)
Examination of the femoral and popliteal veins (if DVT is suspected).
Indications for focused bedside echocardiography (FBE) include the following:
Any patient presenting with chest pain, shortness of breath, or dyspnea on exertion
Code or arrest situations such as pulseless electrical activity (PEA)
Suspected left- or right-sided heart failure
Suspected pulmonary embolism
Suspected cardiac tamponade
Assessment of central venous pressure and volume status
On average, most patients have at least one good or adequate view of the heart (subxiphoid, parasternal, or apical). If a given view is difficult to obtain, try dragging the probe cephalad or caudad one interspace or toward the sternum or midclavicular line. Patients with chronic obstructive pulmonary disease (COPD) tend to have poor parasternal views but good subxiphoid views, as their hyperexpanded lungs tend to push the heart inferiorly. Patients who are obese tend to have poorer subxiphoid views and better parasternal views.
If the subxiphoid view is difficult to obtain because of bowel gas, use the transducer-probe to perform gentle, graded compression. This can often stimulate the bowel to peristalse out of the way. Another technique is to reattempt the view from a position just to the right of midline and try to use more of the liver as an acoustic window.
The parasternal long-axis (PLA) view should visualize the aortic root. If the aortic root is absent, the image is most likely oblique. In this case, angle the transducer slightly in either direction to optimize the image.
The parasternal short-axis view should be obtained with the image plane at the level of the papillary muscles. This ensures a true transverse cut through the left ventricle and allows for proper evaluation of left ventricle function.
If the meniscus of the internal jugular (IJ) vein is not identifiable, try having the patient sit up (if central venous pressure [CVP] is high, the top of the IJ may be impossible to see unless the patient sits up) or lie down (if CVP is low, the top of the IJ may be impossible to see unless the patient lies down).