Transthoracic echo (TTE) in prone patients with COVID-19
In a case series involving 15 patients on prone ventilation, it was
found that raising the patient’s left arm and placing a pillow or a
folded sheet underneath the mid-thoracic wall to maintain the left
hemithorax slightly elevated to allow a comfortable transducer
manipulation resulted in successful apical four and five chamber views
and related measurements in 14 out of 15 patients who were
studied[49]. In another case series involving 8 patients, an
alternative method has been proposed for obtaining adequate TTE windows
in prone patients. Rather than extending the patient’s left arm above
the head, the lower thoracic section of the patient’s air mattress was
temporarily deflated, taking advantage of the gravitational effect of
the heart and its shift toward the chest wall while obtaining an apical
four chamber view\sout. In addition to the traditional apical four
chamber view, the apical five chamber view was also obtainable by
tilting the probe in this position. These views were adequate to
estimate the left ventricular ejection fraction (LVEF), mitral annular
plane systolic excursion, mitral valve and annular Doppler velocities,
aortic valve Doppler velocity, TAPSE and PASP from the tricuspid
regurgitation peak Doppler velocity. Adequate measurements were possible
in seven out of eight patients who were included in this case
series[50].