Abbreviated title: Sustained pharyngeal inflation effects in
upper airway
Abstract
OBJECTIVE: Sustained pharyngeal inflation (SPI) with pharyngeal
oxygen and nose-close (PhO2-NC) can create positive peak
inflation pressure (PIP) inside the pharyngolaryngeal space (PLS). This
study measured and compared effects of four different SPI durations in
the PLS.
METHOD: In this prospective observational study, 20 consecutive
infants aged less than 3 years, scheduled for elective
flexible-bronchoscopy were enrolled. SPI was performed twice in four
different durations (0, 1, 3 and 5 seconds) sequentially in each infant.
PIP was measured for each SPI in the pharynx, and simultaneously took
images at two locations of oropharynx and supra-larynx. Infants’
demographic details and PIP levels, lumen expansion scores and images of
PLS were measured and analyzed.
RESULTS: Twenty infants with 40 measurements were collected.
The mean (SD) age and weight were 11.6 (9.1) months and 6.8 (2.4) kg,
respectively. The measured mean (SD) pharyngeal PIPs were 4.1 (3.3),
21.9 (7.0), 42.2 (12.3) and 65.5 (18.5) cm H2O at SPI
duration of 0, 1, 3 and 5 seconds, respectively; which showed
significant positive association (p<0.001). At assigned
locations, the corresponding PLS images also show significant increase
in lumen expansion scores and number of detected lesions with increase
in SPI duration (p<0.001). The mean (SD) study time was 5.7
(1.2) minutes. No study related complication was noted.
CONCLUSIONS: SPI with PhO2-NC up to 5 seconds
is a simple, safe and feasible clinical ventilation modality. It may
provide enough PIP to expand the PLS and facilitate
flexible-bronchoscopy performance in infants.