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
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 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 vein is not
identifiable, try having the patient sit up, if central venous pressure is
high, the top of the internal jugular 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.
Bibliography
Jang, T., & Oakley, E. (2013, Sept 30). medscape.com.
Retrieved from Cardiac Evaluation using Bedside Ultrasonography:
http://emedicine.medscape.com/article/104401-overview
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