Combination of Bernouilli effect producing maneuver-induced pharyngeal narrowing rate with body mass index as predictive tool for obstructive sleep apnea syndrome

The impact of modified tongue base suspension on CPAP levels in patients with severe OSA

The aim of this study was to evaluate the effects of modified tongue base suspension (mTBS) procedure on continuous positive airway pressure (CPAP) levels in patients with severe obstructive sleep apnea (OSA). From November 2011 to December 2012, a total of 31 patients with severe OSA who underwent mTBS were included into this prospective case series with planned data collection. Prior to surgery, all the patients were subjected to a polysomnography (PSG) and CPAP titration on two separate nights. Following the surgery, patients were subjected to a control PSG and CPAP titration at the sixth month of follow-up period. The preoperative and postoperative mean apnea hypopnea index (AHI), CPAP titration values, AHI during CPAP use and amount of sleeping time with CPAP were compared. Median age was 48 years (range 31-66), and most patients were male (87.0 %). Postoperative mean AHI (44.73 ± 17.05 vs. 19.96 ± 19.52), optimal CPAP value (12.64 ± 1.60 vs. 8.00 ± 1.77) and AHI during CPAP use (3.79 ± 1.78 vs. 2.25 ± 1.81) were decreased, and the amount of sleeping time with CPAP (5.29 ± 0.84 vs. 6.52 ± 0.89) was increased significantly (p < 0.001 for all parameters). The surgery was considered to be successful when 50 % reduction in the mean AHI and/or the decrease of AHI below 20/h were obtained. A total of 24 patients (77.4 %) met the surgical success criteria. The mTBS is a safe and feasible procedure with favorable effects on CPAP levels in patients with severe OSA.

Fractal quantitative endoscopic evaluation of the upper airway in patients with obstructive sleep apnea syndrome

Objective: To analyze computer-assisted quantitative measurements of endoscopic images taken during fiberoptic nasopharyngoscopy with Müller's maneuver that were processed with the use of fractal geometry and correlate them with the apnea-hypopnea index of patients with obstructive sleep apnea syndrome as well as habitual snorers.

Study Design: Diagnostic test assessment for the analysis of images acquired through fiberoptic nasopharyngoscopy with Müller's maneuver and processed with the use of fractal geometry.

Setting: Sleep laboratory in a tertiary care private hospital in Athens, Greece.

Subjects and Methods: A total of 42 subjects (25 patients, 17 control subjects) underwent fiberoptic endoscopic nasopharyngoscopy with Müller's maneuver and polysomnographic overnight testing. Endoscopic images were digitally analyzed, and fractal analysis software was used to determine fractal dimensions of postpalatal airway contour during quiet inspiration and Müller's maneuver. Findings were correlated with the apnea-hypopnea index.

Results: Fractal dimension of collapsed airway and airway collapsibility was shown to be correlated with the apnea-hypopnea index (r = −0.481 and 0.518). We used 9.5 percent airway collapsibility on the basis of fractal dimensions as a cutoff (decided according to a receiver operating characteristic curve) and found that the predictability of obstructive sleep apnea had a sensitivity of 92.0 percent (95% confidence interval 75.03-97.78) and a specificity of 82.4 percent (95% confidence interval 58.97-93.8), with a positive predictive value of 88.5 percent and a negative predictive value of 87.5 percent ( P < 0.0001).

Conclusion: Fractal analysis provides an additional measure of objectivity for the interpretation of computer-assisted quantitative endoscopic evaluation of patients with obstructive sleep apnea. Nevertheless, as confidence intervals show, some uncertainty remains regarding the real population estimate, and therefore additional studies involving larger population groups are encouraged.