Results
In these 20 studied infants (Table
1), the mean (SD) age was 11.6 (9.1) months and the mean (SD) body
weight was 6. 8 (2.4) kg. There were 40 sets of measured data. The mean
(SD) operative time of this SPI study was 5.7 (1.2) minutes.
Table 2 presents the details of the intrapharyngeal PIP, lumen expansion
scores, locations and number of detected lesions on these four SPI
modes. In the collected 40 sets of measurements, the 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, 1, 3 and 5 seconds,
respectively. As shows in the Figure 2, there is positive and
significant (p<0.001) linear increase in PIP levels with SPI
duration from 0 through 5 seconds. In these changes of image sequences,
there was progressive space expansion and significant greater lumen
expansion scores (p<0.001) in all locations of the PLS.
Those pressure-sensitive dynamical lesions, such as pharyngomalacia,
laryngeal malacia, laryngeal cleft, glottic malacia, etc., which might
be overlooked with a low PIP level of short duration SPI. But after
adequate lumen expansion with a high PIP level, definite diagnosis could
be achieved. Significantly higher number of lesions could be detected
with higher PIP levels (p=0.004). With the SPI of 5 seconds, the highest
PIP, and lumen expansion score were achieved, and FB identified the most
number of lesion (p<0.001).
The corresponding levels of PIP, expansion scores, images of each SPI
mode of pharyngeal and laryngeal lesion were illustrated in the Figure 3
and Figure 4, 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 durations. In these changes of image
sequences, there was a progressive and significant space expansion and
greater lumen dimension scores in all locations of the PLS, especially
with existing airway pathologic lesions such as pharyngomalacia, uvular
cyst, vallecular cyst, etc. During FB assessment, these created lumen
expansions also facilitated accurate and comprehensive evaluation of
lesions which were not visible in the low PIP levels but became apparent
with the high PIP levels of longer SPI duration.
All these SPI studies were successfully completed. There was no any
study-related complication such as upper airway bleeding, subcutaneous
emphysema, pneumothorax, desaturation (<90%) or bradycardia
(<100 beat/min).