Fig. 1
A Regional ventilation, perfusion, intrapulmonary shunt and deadspace assessed by lung ultrasound(DC-40S Mindray, Shenzhen, China) and EIT(PulmoVista 500, Dräger Medical, Lübeck, Germany) in a D-pattern case. EIT measurements were continuously recorded at 20 Hz, which were digitally filtered using a low-pass filter with a cutoff frequency of 0.67 Hz to eliminate periodic cardiac-related impedance changes. PEEP = 8 cm H2O from left to right, ultrasound: demonstrated pleural effusion and massive consolidation in the right lower lobe, and color Doppler ultrasound found an absent vascularity in the consolidation region. Pleural effusion frequently appears as an echo-free zone between visceral and parietal pleura, of which the distance indicates the depth of pleural effusion(white arrow). Inside the pleural effusion, a floating consolidated lobe could easily be distinguished. The consolidated region appears tissue-like pattern with no aeration. Within consolidated regions, blood flow signals were defined as pulsatile flow shaped of dot, tube, curve, or branch using Doppler with color-flow mapping in the color mode. Absent vascularity was defined as no pulsatile blood flow was present if the background noise of color Doppler appeared as a colored snowstorm across the image. EIT ventilation image: upper right (UR) 8%, upper left (UL) 48%, lower right (LR) 16%, lower left (LL) 27% (% denoted the ventilation distribution portion in each region of interest). Low ventilated regions are marked in dark blue and high ventilated regions in light blue to white. EIT perfusion image: UR 9%, UL 45%, LR 6%, LL 40%. Regions with high perfusion are marked in red and low perfusion in green. EIT V-Q matching image: percentage of Shunt% area in red was 10.34% of the lung regions, DeadSpace% area in grey 32.41%, and VQ Match% region in yellow 57.24%. Details of the V-Q distribution calculation were described in a previous study [5]. PEEP = 14 cmH2O After lung recruitment and drainage of pleural effusion, from left to right ultrasound: demonstrated decreased pleural effusion and recruited consolidated lung tissue in the right lower lobe. The tissue like pattern disappeared, and the corresponding region appeared subpleural debris and B line. Color Doppler ultrasound also showed the absent vascularity. EIT ventilation image: UR 18%, UL 20%, LR 23%, LL 38%. EIT perfusion image: UR 15%, UL 57%, LR 9%, LL 20%. EIT V-Q matching image: Shunt% 19.23%, DeadSpace% 45.13%, and VQ Match% 35.64%. The white spots (red arrow) moves synchronously with tidal ventilation indicates dynamic air-bronchogram. P = pleural effusion, Lu = lung, Li = Liver, D = diaphragm. B Regional perfusion, ventilation and intrapulmonary shunt assessed by lung ultrasound and EIT in a S-pattern case. SP (supine): from left to right: Ultrasound: demonstrated pleural effusion and tissue-like pattern consolidation in the right (R) lower lobe and the corresponding region on color-mode all visualized two parallel coarse blood flows (white arrows). Red: Pulmonary vessels with blood flow moving towards the probe. Blue: Pulmonary vessels with blood flow moving away from the probe. EIT ventilation image: UR 29%, UL 37%, LR 9%, LL 25%. Perfusion image: UR 11%, UL 17%, LR 30%, LL 43%. V/Q match image: Shunt% 18.53%, DeadSpace% 26.14%, and V/Q Match% 55.33%. PP (prone positioning): from left to right, ultrasound: demonstrated decreased pleural effusion and recruited consolidated lung tissue in the right lower lobe, and color Doppler ultrasound also showed the decreased vascularity. EIT ventilation image: UR 31%, UL 13%, LR 26%, LL 30%. EIT perfusion image: UR 22%, UL 13%, LR 33%, LL 32%. EIT V-Q matching image: Shunt% 14.81%, DeadSpace% 11.78%, and VQ Match% 73.40%