Results
In these 20 studied infants, as Table 1, the mean (SD) age was 11.6 (9.1) month-old and the mean (SD) body weight was 6. 8 (2.4) kg. The mean (SD) operative time of this SPI study was 5.7 (1.2) minutes.
In the collected 40 sets of study data, the measured mean (SD) PIP in the pharynx were 4.1 (3.3), 21.9 (7.0), 42.2 (12.3) and 65.5 (18.5) cmH2O at SPI duration of 0.0, 1.0, 3.0 and 5.0 seconds, respectively. These PIP levels were all positively and significantly (p<0.001) correlated to the durations of the SPI in second.
The corresponding levels of PIP, expansion scores, images of each SPI mode of pharyngeal and laryngeal lesion were illustrated in the Figure 2 and Figure 3, respectively. On the same row, all four images were taken at similar location of same infant but with different PIP levels generated by different SPI modes. Obviously, in these changes of image sequences, there show progressive and significant space expansion, positive correlation, and also greater lumen dimension scores to the associated PIP levels in all locations of the PLS. Especially, when there existed pathologic lesions such as these presented pharyngomalacia, uvular cyst, vallecular cyst, etc. During FB assessment, these created lumen expansions might also help to accurate and comprehensive evaluation of those lesions which were not visible in the low PIP but apparently with the high PIP of long SPI duration.
All these SPI studies were successfully completed. Throughout the whole study, there was no any study-related complication such as upper airway bleeding, subcutaneous emphysema, pneumothorax, desaturation or bradycardia.