Description:
During the COVID-19 pandemic, we performed a series of transthoracic
echocardiograms (TTE) using subcostal view and observed that the
evaluation of the pulmonary valve (PV) and the right ventricular outflow
tract (RVOT) was possible in prone position (PP).1
After placing in PP during invasive mechanical ventilation (IMV), the
patient’s left arm was extended overhead, and a pillow was placed only
under the left hemithorax to elevate it and facilitate subcostal view
(Figure 1). The transducer was placed under the patient, in the left
subcostal position, and an orientation index marker pointing towards the
patient´s left shoulder was used to observe the four cardiac chambers
(Figure 1B). Subsequent subtle upward movement of the transducer tail
permitted us to view the PV and a small portion of the RVOT (Figure 1C,
2A and 2B). A further counter-clockwise rotation of the transducer
allowed us to view the short axis of the RVOT (Figure 1D and 2C). This
approach allowed us to observe the opening of the PV by 2D visualization
and the transpulmonary flow by colour Doppler (Figure 2D). Continuous
Doppler allowed us to calculate the gradients of the PV (Figure 2E), and
pulsed Doppler at RVOT level helped us estimate the pulmonary pressure
based on the shape of its curve and by measuring the acceleration time
(Figure 2F).
TTE has emerged as an alternative for monitoring patients in the PP
during IMV, with adequate imaging achieved because of a proximity of the
heart to the chest wall in PP.2 Previous studies have
reported that apical views allow evaluation of ventricular and valve
function and that of the inferior vena cava.3Recently, a study has reported the performance of a subcostal view
examination in PP and briefly described the PV.1However, it is not described a detailed evaluation of the PV or RVOT.
Our technique has the advantage of allowing evaluation of the PV
function and the presence of pulmonary hypertension.4This is a novel possibility to perform TTE in the PP, where we could
discard the PV disease and evaluate the pulmonary pressure by a
different approach.