Patients with airway foreign bodies have varied presentations. The presence of any radiologic finding suggests that endoscopy should be performed, as a foreign body is probable. The absence of any history or physical examination finding was associated with a low likelihood of a foreign body.
Objective-Determine the role of mastoid volume in middle ear pressure (MEP) regulation. The hypothesis was that inert gas exchange between blood and middle ear (ME) is slower for larger mastoid volumes.
Study Design-ProspectiveMethods-For 21 enrolled subjects, the bilateral surface areas and volumes of the mastoid and tympanum were measured from CT scans in 20 with a wide range of mastoid volumes. Then, 19 subjects were reclined in a chair, fitted with a non-rebreathing mask and breathed room air for 20 minutes (acclimation), a gas composition of 25% N2O, 20% O2, balance N2 for 30 minutes (experiment) and room air for 30 minutes (recovery). Bilateral MEPs were recorded by tympanometry every 2 minutes. The slopes of the MEP-time functions during N20 breathing were calculated to the first observation of Eustachian tube opening and divided by the estimated blood-ME N2O gradient to yield a N2O time-constant. Sufficient data were available for 16 right and 11 left MEs to calculate the time-constant.Results-MEP did not change during the baseline period but, within 10 minutes of breathing the N2O mixture, showed a progressive increase. The right-left correlation for the time-constant was 0.87 (n=10 ears, p=0.001). Regression of the time-constants on ME volume showed an inverse relationship (n=23 ears, r=−41, p=0.05). A better data fit was the curvilinear relationship predicted by a mathematical model of the mastoid acting as a ME ear gas reserve.
Conclusion-These results support the tested hypothesis that the mastoid could serve as ME gas reserve.
Children with DS who underwent AT demonstrated significant reductions in both obstructive and central apneic indices on PSG. A significant number of patients with central sleep apnea demonstrated resolution postoperatively. Additional analysis demonstrated a significant interaction between CO2 retention, adenoid size, and postoperative CAI reduction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.